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CR: A user’s guide to the

technology

A guide to the technology and technical

parameters of community radio in India

N. Ramakrishnan

CR: A user's guide to the technology (2007)

ISBN 81-89218-12-3

This publication may be produced in any media appropriately

acknowledging UNESCO

Published by :

The United Nations Educational Scientific & Cultural Organization

(UNESCO)

UNESCO House

B-5/29, Safdarjung Enclave

New Delhi - 110019, India

Phone: +91-11-26713000

Fax: +91-11-26713001/2

E-mail: newdelhi@unesco.org

Web: http://www.unesco.org/newdelhi

Author, Researcher: N.Ramakrishnan (Ideosync Media Combine)

Editorial Team: Seema Nair, Sajan Venniyoor, Gitanjali Sah

Cover & Binder Design: Inverted Commas, New Delhi

Inside page design and graphics: Mensa Computers Pvt. Ltd., New Delhi

Photo credits :

N.Ramakrishnan:Pages 4, 5, 6, 7, 13, 48, 57, 61, 73, 92-94, 96, 101,103,

104, 165-171, 204

Choy Arnaldo: Pages 14, 25, 26

UNESCO: Pages 11, 38, 76, 90, 100

All others images are courtesy the respective manufacturing companies

Photographs of CR groups in action appear with permission of Samudayik

Radio Mandakini Ki Awaaz and Hevalvaani Samudayik Radio, Uttarakhand

Please send in comments and your experiences with this manual to

newdelhi@unesco.org and:

N. Ramakrishnan

Ideosync Media Combine

177, Ashoka Enclave III

Sector 35, Faridabad - 121 003

Haryana - INDIA

Tel: +91-0129-4131883/6510156

Email: nram@ideosyncmedia.org

Disclaimer:

The author is responsible for the choice and the presentation of the facts

contained in this news piece and for the opinions expressed therein, which

are not necessarily those of UNESCO and do not commit the Organisation.

The designations employed and the presentation of materials throughout

the publication do not imply the expression of any opinion whatsoever

on the part of UNESCO concerning the legal status of any country,

territory, city or area or of its frontiers or boundaries.

(ii)

ABOUT THE AUTHOR

N.Ramakrishnan is a development communications professional, trainer

and author with more than a decade of experience in the development

sector. He is also a cinematographer, editor, director, and technology

enthusiast; and conducts workshops on community radio, developmental

filmmaking and low cost radio and video technology.

With extensive experience in developing community-derived and

community-oriented behaviour change materials, Ramakrishnan has worked

on a number of behaviour change communication tools, including the

National Award winning film Nirankush, on female infanticide in the Indian

state of Rajasthan; and the acclaimed Growing Up/Badhte Hum/Time of

Our Lives video module series on reproductive and sexual health for young

people.

Ramakrishnan works with Ideosync Media Combine, a communication for

development organization based in the NCR of Delhi, India,. He is currently

engaged on several community radio and radio for development initiatives,

including a cross border radio programme series on safe migration and

HIV for Nepali, Garhwali and Kumaoni migrants.

(iii)

ACKNOWLEDGEMENTS

This manual is the outcome of a number of years of practical field work, and

the inputs of a vast number of communication and audio/video professionals

that its has been my pleasure and privilege to work with over the last several

years. Their advice, tips and generosity in sharing their own experiences and

learning has been central to the compilation of the information contained in

these pages.

This manual has also been through an extensive process of review on the

Solution Exchange and CR India e-discussion lists. Mr.Arvind Kumar, Director

(Broadcasting Policy & Legislation), Ministry of Information & Broadcasting,

Govt. of India, participated in this discussion by placing the use of this manual

in the current context. The members of both lists have been more than

generous with their time, and in sharing their vast experience and

understanding of community radio technology and audio equipment for the

betterment of this manual. Their combined knowledge is a wonderfully rich

resource which I have made extensive use of in this volume.

In particular – and without in any way reducing the value of the contributions

by the other members of both lists – I would like to extend my gratitude and

thanks to the following community members who volunteered their time

and energy :

Ashish Bhatnagar, Prasar Bharati (Akashvani and Doordarshan), New Delhi

Ramnath Bhatt, VOICES, Bangalore

Benjamin Grubb, Queensland University of Technology, Brisbane, Australia

Douglas Bell, Education Development Center, Bangalore

Aaditeshwar Seth, University of Waterloo, Canada

Jayalakshmi Chittoor, Centre for Science, Development and Media Studies

(CSDMS), New Delhi

Michelle Chawla, Nomad India Network, Dahanu (Maharashtra)

Frederick Noronha, BytesForAll, Panaji (Goa)

My thanks also to Shri D.Singaravelu, Dy.Advisor (Wireless), WPC, Ministry

of Communication & Information Technology, for his key inputs on the

technical aspects of the guidelines governing CR policy in India; and to

Choy Arnaldo, who has provided several photographs in this manual

illustrating CR experiences from around the world.

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A special word of thanks to UNESCO, for understanding and responding to

the need for this manual; and specifically to Seema Nair at UNESCO, and

Sajan Venniyoor and Gitanjali Sah at Solution Exchange who jointly

constituted the editorial team for this manual. I thank them all for their

enthusiasm and hard work in rearranging, clipping and pruning this manual

into its final shape.

Last – but not least – my thanks and appreciation to my colleagues at Ideosync

Media Combine, who helped organize a vast number of resources into

something that I could use to write this manual; and to the members of

Hevalvaani and Mandaakini Ki Awaaz CR groups in Uttarakhand, who

provided valuable feedback on the kind of information that would make

this manual usable and accessible to its users.

NRK

New Delhi

November 2007

(v)

TABLE OF CONTENTS

Foreword................................................................................................... ix

What they said ........................................................................................ x

Introduction: Who is this manual for, and how should it be used?............ xii

Section A: Community Radio: An overview

Chapter 1: So what is radio, and how does it work? ...............................3

Radio broadcasting: The Process – and some terms .................................3

Radio waves: A brief look at some important concepts ............................ 8

Linking the technology to the production ..............................................10

Chapter 2: Technology I: Setting up a studio space ...............................15

Section A: Siting the CR station..............................................................15

Section B: Defining the spaces ............................................................... 17

Section C: Important considerations while setting up the spaces ............ 20

Chapter 3: Technology II: Studio Equipment.........................................39

Section A: The Broadcast Studio ............................................................39

Section B: The Production Studio .......................................................... 49

Chapter4: Technology III: Field recording equipment ........................... 61

Why do we need field recording equipment? ........................................ 61

What are the main considerations in selecting

field recording equipment? ....................................................................62

What should a field recording kit consist of? ..........................................63

Chapter 5: Technology IV: Transmission equipment ............................. 69

Chapter 6: Telecommunications & other ancillary equipment .............. 77

Section A: Telecommunications & Telephony ........................................ 77

Section B: Other office equipment .........................................................86

Chapter 7: Planning for maintenance & management ........................... 91

Setting rules & regulations in the studio .................................................91

Planning for maintenance ......................................................................92

Maintaining the documentation & plans ................................................93

Maintaining inventories of equipment ...................................................94

Assessing (and investing in) maintenance skills ......................................95

Assessing maintenance costs ..................................................................95

Annual Maintenance Contracts (AMCs) .................................................96

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Chapter 8: Assessing training requirements.........................................101

Assessing training needs ......................................................................102

Training resources ............................................................................... 104

Chapter 9: CR guidelines in India and their implications .................... 105

Section B: Detailed notes on equipment & audio concepts .................121

(See table of contents at beginning of Section B)

Section C: Appendices ........................................................................231

Appendix 1: Suggested setups for CR stations ......................................232

Appendix 2: Audio & Radio equipment manufacturers (Global list) ..... 245

Appendix 3: Index of advisory organizations & individuals .................. 254

Appendix 4: Audio & Radio equipment vendors in India .....................260

Appendix 5: Useful web-based resources ............................................ 265

Bibliography ....................................................................................... 269

Notes pages ......................................................................................... 270

(viii)

FOREWORD

The Government of India earlier this year announced its intention to establish

4000 community radio stations by 2008.

This has brought a flood of questions from prospective Community Radio

applicants/operators and in particular: what equipment do you need to set up

a community radio, and how much would it cost? While there are many solutions

that are available off the shelf, our main line of advice has been “Costs depend

on the context of the Community Radio Station you are trying to build”.

We also strive to bear in mind the Objectives of UNESCO’s programme

stressing promotion of community access and engagement, and the Action

Plan of the World Summit on the Information Society, (Tunis, 2005) which

emphasises values of inclusive and pluralist knowledge societies. It is more

to such inclusiveness and the level of participation of a community, together

with relevant programming rather than the technology, that we owe the

success of a community radio station.

Our further piece of advice therefore, is to “Begin small and grow inch-by-

inch with your community”.

This manual is designed to accompany you in the demystification of each

piece of equipment usually found in community radio stations; its role and

function within a wider social context; advantages and disadvantages of its

usage. For others who dare to be technically more adventurous detailed

notes on equipment are also provided.

As hands-on participatory community development specialists it is in your

interest to be aware of the different options open to you in sourcing,

maintenance and operation of the equipment that is most suited to your

individual needs. This manual is intended as a tool for such information and

we hope you will find it useful in applying this knowledge to your own local

environments.

It is through localisation not only of content, but also of technology that we

may assist in accelerating the community radio movement in India and making

the intentions of the Government a live reality.

Jocelyne Josiah

Advisor in Communication and Information for Asia

UNESCO New Delhi

(ix)

Radio could be the mostRadio could be the most

Radio could be the most

wonderful publicwonderful public

wonderful public

communication systemcommunication system

communication system

imaginable, a giganticimaginable, a gigantic

imaginable, a gigantic

system of channels – couldsystem of channels – could

system of channels – could

be, that is, if it werebe, that is, if it were

be, that is, if it were

capable not only ofcapable not only of

capable not only of

transmitting but oftransmitting but of

transmitting but of

receiving, of makingreceiving, of making

receiving, of making

listeners hear but alsolisteners hear but also

listeners hear but also

speak, not of isolating themspeak, not of isolating them

speak, not of isolating them

but of connecting them.but of connecting them.

but of connecting them.

Bertolt Brecht (1930) -

quoted in Lewis and Booth

(1989)

What they said...

This is a miraculous power. I see Shakti, the

miraculous power of God in it [radio].

Mahatma Gandhi

Radio is the theatrRadio is the theatr

Radio is the theatre of thee of the

e of thee of the

e of the

mind.mind.

mind. Steve Allen

You can make good radio,

interesting radio, great radio even,

without an urgent question, a

burning issue at stake.

Ira Glass

(x)

It’s a pleasure,

a gift, an honor,

to go in front of a

microphone and

communicate.

Larry King

Television is radio without the

imagination. Anonymous

TV gives everyone an image, but

radio gives birth to a million

images in a million brains.

Peggy Noonan

Wolfman Jack

You donYou don

You don’t work fort work for

t work fort work for

t work for

the radio station.the radio station.

the radio station.

You work for the peopleYou work for the people

You work for the people

out there.out there.

out there.

(xi)

Introduction

WHO IS THIS MANUAL FOR,

AND HOW SHOULD IT BE USED?

Congratulations! If you’re reading this, you have taken the first steps on a

long and satisfying journey that should (we hope) culminate in the setting up

and successful operation of a community radio station: A radio station by,

for and from the people. With the Government. of India allowing community

radio stations (CRS) in India in late 2006, a new chapter has begun for those

who have been working towards creating media and technology access for

communities – and to empower ourselves with an understanding of how to

use these technologies to highlight our concerns, our ideas, and our cultural

and traditional practices.

But in the excitement of gaining access to this truly participatory, inclusive

and inexpensive mass medium, we often forget that radio is a technological

medium – and that it calls for communities and civil society organizations

working with radio to have an understanding of the technology, the

equipment, and the processes and parameters that govern the setup, operation

and successful running of a community radio station. It is all too easy to

forget about the technology while we exult in the joy of hearing our own

voices and our ideas over a speaker or radio set; but it is important to realize

that the technology of radio is what allows us to preserve these thoughts and

send them out to our listeners.

That could be your cue to say, Uh-oh, I’m not a technical person; this looks

like it’s going to lead to a lot of tech stuff - I’m not going to get all of this!

How do I begin to understand all the jargon and the science?

Relax. That would be true – if this was a manual that intended to explain the

construction of electronic circuits or the repair of complex recording and

transmission equipment. But it’s not that kind of manual: This is a manual

for the everyman, the interested community member, the hobbyist, the NGO

worker and all those of us who run for help when our TV remotes and

cellular phones misbehave. In short, this is going to be an easy introduction

to the technology of radio.

Reading this manual may not bring you to a level of understanding where

you can take all the decisions and select all the equipment by yourself –

especially since radio equipment changes and evolves all the time – but if

you read this book cover to cover, it’s probably going to give you a feel of

the wide variety of technology options, decisions and concepts that you’ll

have to keep in mind while setting up a CRS. And it’s going to help you take

informed decisions on all those things.

(xii)

So, in a nutshell, what this manual hopes to present is -

1. A user level understanding of how to set up and equip a CRS, and a taste

of the kind of decisions you’ll have to take while planning your CR set up;

2. An understanding of the types of equipment that a CRS requires, their

functions and the costs involved;

3. An understanding of how the various components of a radio production

and the broadcast process work together;

4. An understanding of CR related regulations, technical parameters and

the licensing procedures applicable in India;

5. Enough insight into all the ‘tech stuff’ to inspire you to learn more about

the electronics and physics part!

What it’s not going to do is make you an expert on every aspect of radio and CRS

setup – that’s beyond the scope of any single book or document, and requires

years of practical experience and learning. It’s going to place some options in front

of you and it’s going to give you further resources you can access to learn more:

Web based and print material, as well as organizations and individuals who can

advise and assist you while you learn and build your CR setup.

It is also important to stress that community radio stations work out of single

rooms with basic equipment; as well as dedicated buildings housing multiple

studios and packed with all kinds of high technology. Both can produce

brilliant, locally relevant, interesting programmes. It’s up to you to decide

what kind of a setup is most appropriate for your station, a decision you

must base on five things:

1. The kind of programmes that you plan to broadcast;

2. The amount of money at your disposal;

3. The kind of spaces that are available for you to set up a CR station in the

area you will be operating in (rented or self owned; constructed to your

requirements or an existing space reconfigured);

4. Your ability to handle the costs and effort required to maintain your

equipment, and support the costs involved in acquiring consumables

and recurring costs like the spectrum fee; and finally

5. Your ability to access trained people to operate and maintain your

equipment (and/or training resources to build a pool of trained manpower

to fulfil these functions.)

Depending on a combination of these factors, you may mix and match and

adapt the ideas that you will find in this manual to arrive at a unique solution

which will meet your requirements.

In the same spirit of selection and adaptation, we have also tried to make this

manual as adaptable to your needs as possible: To start with, we’ve included

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several notes pages at the end of this manual so that you can add your own

notes and comments based on your own research and experimentation. We’ve

also included a variety of diagrams and illustrations/photographs to give

you an idea of the equipment, devices and setups referred to in the text.

We’ve also tried to include helpful notes and comments where possible,

identified by the following icons:

Warning! Things you must remember to avoid damage to

equipment or injury

Remember! Things you should keep in mind from the

information immediately preceding the icon.

Maintenance related information that you should remember

to keep your equipment in good working order.

Cross references to other parts of the manual. This symbol may

also refer you to the Detailed notes on equipment section (Section

B) that follows the main manual. This includes detailed

explanations of several concepts and types of equipment, to allow

you to understand equipment specifications better.

The appendices at the end of this manual give you lists of equipment vendors,

lists of advisers and organizations already working on CR and suggested

equipment setups on which you can base your own assessment of the

equipment combinations you require. All these lists will need revision as time

goes by: New equipment and equipment suppliers turn up all the time, so it is

probably a good idea to jot down information on any new vendor or piece of

equipment that you come across. All the costs are in Indian Rupees, and have

been converted from US Dollar rates at 1 USD = INR 40, the rate current at

the time of publication of this manual. (But the exchange rates and prices

change all the time too, so do check on this before you take any final decisions!)

Last, but not least, remember that this manual is not an encyclopaedia – and it’s

not trying to be one. This is a ready resource for the interested user, which you can

also use as training material. It is impossible to give a detailed understanding of

everything that is included in this manual in a single volume. But if this manual

leaves you feeling a little more confident about your understanding of the technology

of community radio, we’ll consider its job done.

We welcome your comments on the manual, so that we can

constantly update and revise this document. Please write in to the addresses

given on the first flyleaf of the book.

Once again, welcome to the world of community radio! We hope this manual

plays a part in improving your understanding of the medium and the

technology involved in running a community radio station.

(xiv)

United Nations Educational, Scientific and Cultural Organisation

Section A

Community Radio : An Overview

United Nations Educational, Scientific and Cultural Organisation

SO WHAT IS RADIO AND

HOW DOES IT WORK?

To many of us, the first time we listen to the radio can be a magical experience.

The prospect of using a device that seems to be an illimitable source of so

many different kinds of music and programmes is a stunning concept, and

many of us struggle to come to terms with it.

One of the trainees at a workshop I conducted, who came from a small

village in a remote part of the country, told me that the first time he saw and

heard a radio, he spent a lot of time debating whether he should open it up

and release all the people inside it. He didn't - but as he will attest to, the

experience is one to which we grow quickly accustomed - even addicted.

Few of us stop to ponder about the process by which the sound we are

hearing is captured, joined, corrected and sent out to the little box in front of

us. How does a programme get made and go on air, anyway? To understand

this, it's important to have an overview of the entire process of radio

broadcasting. We'll start by looking at the broad picture, and as we go

further along in this manual, we'll have a look at each of the processes and

equipment involved in greater detail.

Radio broadcasting: The processes - and some terms

The process of making and broadcasting radio programmes combines

teamwork, creativity, punctuality and technology. It often involves a number

of people working in tandem and with reference to each other; and it's an

intricate process where every part of the chain has to work correctly for the

programme to be of good quality and for it to reach the listener on time.

From a holistic point of view, radio broadcasting includes five discrete

processes:

1. Research and pre-production (ideation on the programme, and preparing

for the production)

2. Production (Recording or gathering the sounds that will be included in

the programme)

3. Post-production (Editing, or selecting the best portions of the recorded

sound, and assembling them together in a logical and coherent fashion;

and finalizing the programme)

Chapter 1

United Nations Educational, Scientific and Cultural Organisation

Members of a community radio group discuss programme

ideas with members of their community

4. Transmission/Broadcast (Sending the programme out over the airwaves,

so that your listeners can listen to it on their radio sets)

5. Feedback (Getting your listeners' opinions and inputs on the programme

that was broadcast, so that future programmes can be improved.)

Let's have a closer look at what exactly each of these steps involves:

1. Research and pre-production : As with most things in life, the process of

radio broadcasting begins with an idea - and research. The idea can be

based on your observations (say, problems with the water supply in your

area) or a recent event (say, someone in your area winning a dance contest);

or on the basis of a need felt by the listener group or 'audience' that you are

addressing (say, you receive a request to make a magazine programme on

local events). The research (often called formative research, because it

helps 'form' the programme) involves the process of reading any background

material that is available on the idea, along with meeting people within the

community who know more about the issues that need to be included in the

programme. Once you have gathered all this information, you start identifying

the specific people who you would like to interview or record for the

programme, as well as the other sounds that you will include in the

programme to give listeners a feel of the places and people who are presented

in the programme. The last step in this process, of course, is deciding the

logistics of the production - that is, the setting up of appointments, deciding

when to record your interviews and sounds, and deciding on and arranging

for the equipment that will be required.

As we shall see, this is the least technological of the four steps, as it primarily

requires only your notes, paper, pen - well, a computer if you have access to one -

a telephone (or other means to contact people)…and time. At the end of the pre-

production process, one should ideally have:



A complete outline script for the programme (if it's a fictional programme,

like a radio drama, then this will include the final dialogues for all the

United Nations Educational, Scientific and Cultural Organisation

characters; if it's a documentary or magazine programme, this will include

a reasonably detailed outline of what you expect the interviews to be like,

along with references to the sounds you will be recording);



A run down sheet, which is a production schedule, and gives a day by

day and hour by hour definition of when, where and what you will be

recording;



A time frame within which you expect to complete the recording and the

final programme. (This last may often not be completely in your hands,

especially if you are broadcasting on a regular basis - in which case, the

day and time each programme needs to go on air, every week, is really

how your schedules are decided.)

2. Production : This is the process of actually recording the voices and

sounds that you will need to make the programme - and this is where the

technical part of the broadcasting process really begins. We use a variety of

devices and material to record or store the sound we are gathering, so that

we can arrange it in the way we like later on.

For more on recorders and microphones, see Chapter 4: Field Recording

Equipment on Page 63

The recording process follows the schedule and script that were developed

during the first step. During this process, we ensure that the sounds we are

gathering are recorded at good quality - that is, following the technical

parameters that we need to store the sound in a way that mimics the original

sounds as closely as possible - and in a way which allows us to use and

discard portions of it. We also keep checking to ensure that our recordings

are relevant to the script for the programme.

A programme recording in process

At the end of the production process, typically, one should have:



A completed set of audio recordings and source materials (including

archival material, if required, and sound effects);

United Nations Educational, Scientific and Cultural Organisation



A field log sheet, which gives details on the audio recorded on each cassette

tape/disk used at the field recording stage. A good field log sheet will give

you a preliminary idea of the recordings you have managed to obtain.



Notes on how to rewrite the script, based on your outline script and on

your assessment of which recordings are good enough to be included in

the final programme.

3. Post-production : Post production starts with the process of listening to

the recordings we made during the production phase, and selecting the

portions that we would like to keep in the final programme. (The usual -

though not entirely recommended - practice is to record as much material as

possible within the time and resources that are at our disposal, so that we

have the luxury of selecting the best sections.) This process, called logging,

should result in a list of the relevant sections that you will refer to while

editing, which is the term for the process of selecting and ordering our

sections of sounds. Editing is the main part of the post production process,

because this is where the raw material that we have gathered is shaped into

the logical and orderly form suggested by the script we have written.

For more on editing equipment, see Chapter 3/Section II: The Production

Studio on Page 57

When the editing is complete, the music (if any) selected and the arrangement

finalized, we 'mix' the sound. Mixing involves the adjustment of the loudness

of the various sounds we have incorporated, so that the programme is

clearly audible, comfortable to hear, and feels seamless. The last step of the

post production process is the mastering of the programme, where we store

the final edited and mixed version of the programme in a way that allows us

to broadcast or transmit it.

4. Broadcast/Transmission : The final step of the radio broadcast process

involves using the transmission equipment to put the programme 'on air'.

Essentially, this means combining the sound of the final mastered programme

with a radio signal and broadcasting it (sending it) through an antenna that

A Volunteer at a CR station edits a programme

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allows the combined signal to reach across space to your listeners' radio

sets, where they can hear it.

For more on transmission equipment, see Chapter 5: Transmission Equipment

on Page 69

The process of transmission is nearly instantaneous, which means the

listeners can hear the programme almost exactly at the same time as it plays

out over the transmitter. It also involves a precise technological process of

controlling and refining the radio signal that is broadcast, so that listeners

can listen to it at a specific setting on their radios, which is how one identifies

a radio station. (90.4 MHz, say, or 102.8 MHz).

5. Feedback : Our work doesn't stop once the programme goes out over the

airwaves, of course - we also need to understand what our listeners think

about the programme and whether they understood it or not. When you are

standing face to face with someone, it is relatively easy to judge whether the

other person understands what you are saying (and what he or she thinks

about your programme) from their expressions, their responses and their

body language. But when the listener is unseen, as happens when using

electronic media like radio or television, we have to evolve processes that let

us obtain regular feedback. This usually involves mechanisms like a postal

or email address that listeners can write to; or a phone number or website

where listeners can leave their comments. It also means you have to look

regularly into these comments and inputs, and revise your programmes

accordingly. The radio station can also increase listener inputs and

interactivity by creating phone in shows where callers can call a 'live' number

and be heard as part of the broadcast.

For more on phone in equipment, see Chapter 3/Section I: The Broadcast

Studio on Page 46

Listeners' letters programmes, where selected letters received are read out

over the air, and request programmes, which offer listeners the opportunity

to request music or specific types of programming, are also an important

way to incorporate feedback.

A CR group volunteer records a listener's feedback

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Radio waves: A brief look at some important concepts

Before we move on, it's important that we understand some basic

concepts about radio - and radio waves in particular - so that some of

the terms we will be using as we move further make sense. (Some of you

may remember this from your physics classes in school!)

We've all seen ripples form in a pool of water when we toss in a pebble:

The ripples start at the point where the stone hits the water, and spread

out in concentric circles from that point outwards. Simply put, the energy

the flying pebble possessed at the moment it hit the water surface has

been converted into the up and down movement of the water particles,

which have now formed WAVES. So a 'wave' is an up-and-down or

side-to-side movement of the particles in a medium, which we usually

illustrate like this:

Radio waves are also similar to the ripples we see, except that they are

not mechanical (in the sense of the water actually rising and falling):

They are electromagnetic, which means they are actually rises and falls

in the strength of a electrical-magnetic field around the point where the

wave originates. (Visible light is also an electromagnetic wave - we don't

really see anything oscillating or rising and falling, but we can perceive

the light from an electric bulb perfectly well. In exactly the same way,

when radio waves are emitted, we don't see any physical movement of

any medium, but we can build electronic devices that can measure

these waves and interpret them for us.)

Radio waves are emitted naturally by radiant sources like the sun and by

radioactive minerals like uranium as they decay. But we can also build

artificial sources of radio waves - exciters or transmitters - that we can

control and use for our purposes.

Contd...

Fig 1-1. Simple sine wave

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There are three properties of a radio wave that we will be most concerned

with in our work with radio:

1. Amplitude : This is the difference between the highest and the lowest

portion of a wave, and is a measure of the strength of the wave. The

larger the amplitude, the higher the energy of the wave, and the greater

the distance the radio wave will travel.

Frequency is measured in Hertz (Hz); and where radio is concerned,

more often in KHz or MHz, which are measures equivalent to 1000 Hz

and 1,000,000 Hz respectively. (Now you know what FM 104.7 means

- the 104.7 refers to the frequency of the station, 104.7 MHz, which is

where we need to tune our radio sets to receive the station's signal.)

2. Frequency & wavelength : Frequency refers to the number of waves

that pass through a given point in space every second, like this:

Contd...

Fig 1-2. Amplitude

Fig 1-3. Frequency

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Wavelength refers to the distance between two successive waves, as

shown here:

If you'll think about it a bit, frequency and wavelength have an inverse

relationship, which means the greater the frequency of a wave, the

shorter the wavelength; and vice versa.

Linking the technology to the production

Back to figuring out where the technology part overlaps the stages of making

a radio programme, then. Let's understand where the technology plays a

part within each of these five processes we just saw:

1. Research & Pre-production: As we have seen, this is not a particularly

technology intensive phase. An understanding of computers - especially the ability

to write documents, and do research on the internet - could be the primary

'technological' requirement in this phase, as is one's ability to use a telephone to

make arrangements, talk to people and set up the production phase.

For more on office computer equipment, see Chapter 6: Telecommunication

& Other Ancillary Equipment on Page 86

2. Production: The very first part of the radio broadcasting system is the

conversion of the sound we want to preserve into electrical energy, so that

it can be stored (recorded). This is achieved with a microphone, a device

that converts - or transduces - sound energy into electrical energy.

For more on microphones, see Section B: Microphones on Page 198

Once the sound is converted into electrical energy, we can not only store it

and recreate the original sound from it a later time, we can make changes to

it in a variety of ways: The audio signal, as it is now called, can be amplified,

or made louder; it can be filtered to remove unnecessary portions of it - and

most importantly for us, it can be edited and joined to other audio signal

sections.

For more on recorders, see Section B: Field Recorders on Page 184

Fig 1-4. Wavelength

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The microphone is usually connected to a device that stores the audio

signal in a retrievable form. These devices, known as recorders, range from

small portable units to very large and highly accurate models.

The electrical signal may be stored through a second process of transduction,

in the form of analog or digital data on a magnetic medium (tapes, hard

disks), digital data on electronic solid state memories (compact flash and

secure digital cards), digital data on an optical medium (CDs, DVDs, Blu-Ray

or HD-DVD disks), or even as a combination of both (minidisks or MDs).

3. Post production: The post production phase is still more technology

intensive: Not only do we now have the audio signals recorded during the

production phase (in one or more of several media), we may want to record

more sounds to add to what we have already recorded: That means we have

more work for our microphones and recorders. We may also use a variety of

already recorded sounds from other source equipment - CD players, DVD

players, cassette decks - that will also provide us more audio signals.

For more on CD players, see Section B: Compact Disc Players on Page 141

For more on cassette decks, see Section B: Cassette Tapes & Cassette Recorders

on Page 134

Once all this is gathered together, and our selection of audio signals made,

we will edit the programme on an editing console or a computer using

suitable software that lets us pick, order and mix the audio signals.

For more on editing consoles, see Chapter 3/Section II: The Production

Studio on Page 57

If we are using modern digital equipment to edit, the process may involve

converting the audio signals once more from the format they were recorded

in into digital data, which can then be manipulated on a computer.

For more on digital audio, see Section B: Analog & Digital Audio on Page 124

CR volunteers learn to edit audio on a computerized editing system.

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The final mix or master can then be removed from the editing console or the

computer in whatever format we choose, and on our choice of media for

broadcast. We may also use a variety of signal processors - mixers, filters,

equalizers, limiters - at any point in this process to make corrections to the

quality of the audio.

For more on mixers, see Chapter 3/Section I: The Broadcast Studio on Page 44

and Chapter 3/Section II: The Production Studio on Page 54

For more on compressor/limiters consoles, see Section B: Compressor/Limiters

on Page 149

A recorder connected to a portable digital

editing console for the transfer of recorded

material. The transferred audio will then be

edited during post production.

4. Transmission/Broadcast: Perhaps the most purely technological step of

the entire broadcast process, transmission involves the combination of the

final audio signal of our programme along with a radio wave of highly

specific and identifiable characteristics; and the transmission or broadcast

of the combined radio signal. The three primary items of equipment required

to do this are a playback source to play back the final audio signal/programme

(say, a cassette deck or a CD player), a transmitter to combine the audio

signal with an internally generated radio wave; and an antenna that lets us

radiate the combined radio signal into the air.

For more on transmission equipment, see Chapter 5: Transmission Equipment

on Page 69

At the listener's end, this step requires the use of a radio receiver set - more

often shortened simply to 'radio' - to catch or receive the signal we have sent

out. The radio receiver allows the listener to tune the set to receive the

specific wave that we have broadcast, and extract the audio signal from it.

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Listeners in the community listen to a radio programme

The extracted audio signal, once again in the form of electrical energy, is

then subjected to a transduction process in a loudspeaker or a headphone

- devices that change the electrical energy back into sound, so that we can

listen to it.

5. Feedback: Strictly speaking, simple feedback processes don't need any

technology at all - the simplest feedback process is to ask listeners to write

letters to the station! The technology part becomes important if we ask

listeners to email or phone in their comments (in which case we need an

internet connection and a computer); a telephone line or mobile connection

(possibly with a recording system attached so that we can receive and store

comments that are phoned in); and if we're ambitious, an adapter that lets us

connect callers directly to the studio for a 'live' phone in programme where

they can be heard or recorded as part of the programme.

So that, then, is a summary of the way the technology, the creativity and the

teamwork that go into producing a radio programme go together.

Ready for more? Plunge on!

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CR volunteers from Radio Tambuli in the Phillipines learn about

radio recording equipment. Learning about radio and transmission

requires a sense of application and interest, rather than a

technical education or a background in engineering.

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TECHNOLOGY - I

DESIGNING THE STATION & STUDIO SPACES

Chapter 2

In an ideal world, members of every community would be able to build their

own CR stations to suit their own unique and specific requirements. But it’s

not an ideal world, and CR stations often have to adapt to whatever spaces

are available to it – usually a rented or community donated pre-built space

that may not entirely meet the station’s needs.

This makes understanding the station’s design and infrastructure doubly

important, because it means we have to be clear about each of the adaptations

we may have to make – why we need to do it, and how best to do it in order

to make it meet our requirements. Let’s start by looking at some basic issues

we need to address while setting up a community rardio station.

Section A: Siting the CR station

There are four primary criteria for selecting a site for your CR station:

1. Local geography and terrain;

2. The physical distribution of the community your station will be

broadcasting to;

3. The strength of the radio signal you will be transmitting;

4. Local noise levels

Of these four considerations, the primary consideration is easy accessibility

by the members of your community: The very essence of a CR station is that

members of the community should be able to participate in the process of

making programmes. So it won't do to have the station in a place where only

a few of your listeners will be able to access it. Many CR stations work out of

spaces close to the village panchayat or community center. Others are set

up near local crossroads or market places. Think about all the members of

your community when you decide a site for the station. Ideally it should be

a place which all sections of the community can access: Young and old,

men and women, able bodied and physically challenged.

Having said that, we also have to ensure that there isn't too much noise

around the CR station itself. Your recording areas and working areas may

need to be comparatively noise free to ensure good audio quality. A noisy

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marketplace, for instance, may force you to adopt much more extensive

measures to isolate yourself from the noise than usual.

In most cases, the antenna/mast and the station are located in close proximity

to each other for a variety of technical considerations. Since FM radio

transmission is line of sight, the transmission can only reach areas that can

electronically 'see' the transmitting antenna. This means we must choose a

site that does not have too many natural or man made obstacles in the path

of the radio signal - that is, it would be preferable to not choose a site where

a hill, mountain or high-rise building could prevent some of our potential

listeners from hearing the station's broadcast.

The line of sight principle, however, can present some direct benefits as

well: CR stations generally have transmitters of limited output, as they are

meant to service smaller areas - but selecting a good site for the station can

maximize your transmission range. Just as standing on a tall hill can give

you a commanding view of the surrounding area, placing your antenna at a

high vantage point can increase your effective range, and let you broadcast

to a larger audience.

Remember that these are just a few points you need to consider while selecting

the site for your CRS: There's always a trade off between all these criteria,

and a site that may be excellent from the point of view of one of these criteria

may fail miserably on another. You will have to weigh your options and

select a site which combines as many of these qualities as possible. Also

keep in mind that the spaces and sites a community is able to create or

develop for a CRS are often more a matter of convenience and ready availability

Fig 2-1. Radio shadow area caused by obstructions near antenna

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than any of these considerations - though it would be nice if the community

as a whole can be sensitized to these issues so that its members can weigh

possible options before taking a decision.

Section B: Defining the spaces

There are three types of spaces that a community radio station generally needs:

1. A broadcast studio: This is the primary studio space for the station, the

place where the programme audio is broadcast from and the programme

presenter (or compere) sits. This space is often used as the 'live' studio, from

where audio is played out to the transmitter, and where one or two person

interviews can be conducted by an interviewer.

For more on equipment for a broadcast studio, see Chapter 3/Section I:

The Broadcast Studio on Page 39

2. A production studio: This is the space where recordings can be done,

and programmes edited and refined for later broadcast. The production

studio is usually equipped with a sound booth or recording floor, where

sound can be recorded in carefully controlled conditions.

For more on equipment for a production studio, see Chapter 3/Section II:

The Production Studio on Page 49

3. Office space: Somewhere where we can meet visitors who visit the station,

and where the people working at the CR station can work together on

production related or administrative tasks.

For more on office and telecommunication equipment see Chapter 6:

Telecommunication & Other Ancillary Equipment on Page 77

A small CR setup may actually have a single space that fulfills all these

functions, and that's perfectly all right. The most common approach for

middle level CR stations is to have a single space setup that combines the

functions and necessities of both studio spaces - including a small recording

floor - with a separate office cum meeting space.

If you have more funds and access to more space, you might like to define

clearly demarcated spaces for all three; and there's really no limit to how

large and well equipped each of these spaces can be.

Thus a simple setup for a single room CR station could be like like the one

shown in Fig 2-2 (below).

The single room acts as both broadcast and production studio, or multi-

purpose studio, and is also used to store the studio materials and equipment.

Realistically, this space should be at least 12 feet long and 12 feet wide: Any

smaller, and it would really be cramped!

A two or three room CR station setup (Fig 2-3) on the other hand, gives us

a little more flexibility to arrange our spaces. It could still have a single studio

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Fig 2-2. Simple single room CR setup

space that combines the production and broadcast units, but could include

a separate space in which to meet people and run the administrative functions

of the station.

Fig 2-3. Simple three room CR setup

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A still more complex CR station setup could resemble something like this:

Fig 2-4. Larger CR setup A

In this kind of setup, the main office and reception lead to the studio spaces, but

can be kept quite separate in operation. More importantly, it means the production

studio can carry on with its work of preparing features and 'canned' (pre-recorded)

programmes for broadcast while programme hosts continue playing out

programmes and doing the live programmes from the broadcast studio.

Proposed

Production

Studio

Voice

Booth

Broadcast Studio

Programme

Manager’s Office

Bathroom

Outdoors

Reception

Area

Fig 2-5. Larger CR setup B

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Section C: Important considerations while setting up the spaces

Besides deciding the broad separation of your station and studio spaces,

there are some important additional considerations to keep in mind. Thinking

about these in advance helps to make operation and utilization of the station

facilities and studios easier, even while it helps us keep everything orderly

and easy to maintain.

1. Dust free atmosphere

The primary concern with all studio spaces is keeping them dust free and

clean. Dust and grime are the worst enemies of sensitive broadcast and

production equipment - and a major portion of the defects and breakdowns

that happen in studios could be avoided with simple dust proofing and

preventive maintenance.

For more information on maintenance see Chapter 7: Planning for

Maintenance & Management on Page 91

The doors leading to the studio spaces should fit well, and should be kept

closed (if not locked) whenever possible. You may have to equip some or

all of the doors with rubber gaskets in order to make them dust proof.

Since the studio spaces are likely to be entered and used frequently by

members of the community, it's probably also a good idea to build a work

ethic and a system where everyone can be inspired to treat the station

spaces as their own, and keep them neat and clean in much the way they

would their own homes. (Strategically placed signs all around the office

and within the studio may play a useful role here - inspire people to help

keep dust out!)

Dust free also means leaving all street shoes outside - a shoe rack for this

purpose is probably a good idea - with people in the studios either in socks

or barefoot. Some stations like to keep separate sets of slippers that are used

exclusively within the studio space.

Note that the diagrams given here are suggestions based on existing

CR setups - they are not meant for you to copy literally while setting

up your own CR station! Use these as a reference to conceptualize

your own setups, which will probably have to work with a different

layout. It's often a good idea to start with whatever spaces are available

and expand slowly rather than try and set up a sprawling multi-room

set up right away. The idea, after all, is to get programming on the air

first, rather than see the station as an end in itself! As your community's

programming needs increase and your volunteer base and staff

increase, you can expand and equip your station spaces bit by bit.

This will not only allow you keep your initial costs low, it will also

allow you to think about each section of the station as you set it up.

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Spaces that are used for CR studios are often not designed for a radio station

type setup, so they often have inconvenient doorways and windows. If you

are faced with multiple entrances and exits, it is wise to plan your space in

a way that allows you to use one of the doors as the primary access point.

Similarly, windows can be bricked up or otherwise built over to close the

space or - and this is usually much nicer - sealed with double pane glass, so

that dust stays out even while the light can still come in. Double glazing also

plays a dual role for acoustic treatment (see below).

Try to keep the space utilization logical and easily cleanable: Don't

design nooks and crannies that are hard to reach, because that is a

recipe for dirt and disaster.

2. Air conditioning

Air conditioning is by no means mandatory or even necessary for a CRS: If

your CRS is built around low cost cassette recorder based equipment, or

hardy solid state memory devices, it may be totally unnecessary to air-

condition the studios. Simple precautions like having an insulated terrace,

or housing your CRS in old-fashioned double walled or thick-walled high-

ceilinged buildings may be an equally effective solution to keeping equipment

cool and protected. If your station is situated in the hills, or by in a coastal

area, the weather conditions may be temperate enough to dispense with air

conditioning.

However, depending on the local weather conditions and the kind of

equipment that you have invested in, air-conditioning on some scale may

have to be considered. If we seal all the windows in order to keep the

studio(s) dust free, then air circulation and ventilation inside the studio spaces

can be a problem. So let's just say that if the outside temperature and dust

conditions warrant it, and if you can afford it, it may be wise to invest in air

conditioning units for the studio spaces, both in the interests of keeping the

spaces cool and so that there is some filtration of the air inside. (More

complex setups could include an air filtration unit, but that would be a

luxury for most CR stations.)

Where they are required, the best ACs for studio use are split air conditioners,

where the blower unit is in the studio, but the condenser and the fan unit,

which make most of the noise, are safely outside the studio. A professional

and expensive setup would probably dispense with individual AC units

altogether, and set up a central ducted AC system, with a cooling tower on

the terrace or in the grounds outside the station - but that is a prospect that

should only be considered if you have a lot of funds at your disposal, and a

very large space with a number of rooms and studios.

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Having said that, air conditioning, while attractive in the hot and dusty

conditions that are common across much of South Asia, has its own downside

- and it can be a serious downside:

1. ACs require a regular mains power supply - if your station is in a power

poor area, or has regular power cuts or 'brown-outs', it could render an

investment in ACs pointless.

2. ACs consume a lot of power and are expensive to run. If your wiring is

not up to the mark, and you cannot afford a big power bill, ACs are a bad

idea. The wiring will have to be of good enough grade to take the load an

AC places on it, often 1500 - 2000 watts or more.

3. ACs need maintenance too - It's not enough to simply install an AC and

use it whenever you want. You have to plan for a regular maintenance

schedule for the unit, and keep it in good running order, which adds to

your maintenance related expenses and responsibilities.

Making an estimate of your AC requirements

The cooling capacity of ACs are rated in BTUs (British Thermal Units) or

more usually in tons (1 ton = 12000 BTU per hour). The ton measure

refers to the volume of air that can efficiently be cooled by the AC, and

1 ton, 1.5 ton and 2 ton ACs are most common.

Divide the square feet area of your room by 600 to arrive at the basic

tonnage capacity required.

zAdd 0.5 tonnes for every 10 people occupying the room at the same

time.

zSimilarly add 0.5 tonnes for every 1500 watts of appliances or lighting

present in the room (A computer would consume about 300 watts

and a regular bulb, 40 to 60 watts).

Calculate the volume of your space on a similar basis for a rough estimate

of the AC capacity that you need.

3. Acoustic treatment

When we record sound, it's always a good idea to record the sound as

cleanly as possible - that is, we try to record the sound as faithfully as possible,

with no unnecessary background noise and as little echo or reverberation

as possible. By reverberation - or reverb, as it's more commonly known - we

mean the hollow sound that you hear when you speak or make a noise in an

empty room: The sound bounces off the walls all around you, and reaches

your ears a fraction after the original sound reaches you, giving it the

'hollowness' or echoing quality. (Anybody who has ever whistled or

hummed a few snatches of a song in a bathroom knows this as the

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'bathroom effect': The hard tiled surfaces in a bathroom emphasize the

effect quite a bit.) As human beings, we are able to discount the reflected

sound in our brains, but machines cannot do this - and the sound a

microphone 'hears' in a room with a lot of reverb can quite ruin the recording.

We increase the clarity of the sound in our studios by acoustically treating

the space: Simply put, this means we prevent outside sounds from getting

into the space (sound proofing), and we find ways to keep the reverberation

of our studio space down.

There's always a debate about the acoustic treatment part of studio set up:

How much of a priority should it be for a community radio setup? There is

no easy answer to this question, except to say that it depends on your

choice of spaces and the availability of funds. Personally, I would say the

cost or size of your setup should not be an excuse for poor audio quality or

production values, so you should try and make the best use of local expertise,

your research and your creativity. A CR setup can afford to make more

compromises and can afford to deal with less stringent recording needs

than a commercial station; but a sense of application can achieve a lot, as

we will see.

a. Sound proofing: The first step to acoustic treatment is the isolation of the

studio from outside noises. And the first step to achieving that is to set up

your station and studio space in a quiet locality as far away from busy

thoroughfares as possible, while remaining within the community. (This is

usually easier in a rural area than in a town or an urban area, but if you look

hard enough, you should be able to find a space that is less exposed to

outside sounds.)

The other way to soundproof your studio is to have multiple surfaces with

air trapped between them.. For example, it's usually a good idea to have a

set of double doors at the studio entrance, if that is feasible. (At the very least,

a thick, well fitting door with rubber gaskets around the door edges should

be possible, with some help from a good carpenter.) The air trapped between

the two doors in a double door system (a 'sound lock') keeps outside sounds

from traveling through. Studio doors should preferably be fitted with a small

glass panel - like a porthole - at eye level, so that one can peer in before

actually entering, in case a recording or broadcast is taking place.

It helps greatly to have thick outside walls - 9 inch thick load bearing walls

are great - and if the studio isn't part of a wall-to-wall construction setup

where the next building or house physically shares the same wall, that's

great as well. Studio windows that open to the outside should ideally be

sealed and double glazed. This means we have to install two window panes

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Note that the two glass panes are angled slightly with reference to each

other - this is so that any sound that enters the outer pane doesn't end up

being reflected repeatedly between the two panes, causing them to rattle or

buzz. It's also a good idea to ensure that the channels the glass panes rest in

and the frames holding them in place are padded with thermocol or a thin

strip of rubber.

Glass Pane

Half Inch

Air Space

Fig 2-6. Double glass window cross section

of glass that are at least 5 mm thick, with about 5 - 8 cm of air in between,

like this:

Properly used and worked on, outside windows on the studio spaces

are not an issue at all - in fact, once you've cut off the intrusion of

external noise, it may excite attention about your work from passers-

by who can watch your studio in action, especially if your studio

windows face a street. Internal windows opening into other rooms in

the station are equally interesting if designed well, as it lets other

people in the station remain involved in what's happening in the

studios and lets visitors peek in as well.

Remember that sounds slips through the smallest gaps - so pay

attention to small crevices and ventilator spaces. All of those are

potential sources of unwanted outside sound!

b. Cutting down the reverberation: Now that we've cut out the outside

sound, it's time to explore how to cut down the reverberation in our studio

space. Reverberation treatment is especially vital for the spaces within the

station where the microphones will actually be used - the recording booth

or stage, for example.

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Radio Muye, Suriname (Caribbean) – note the creative

use of rattan panels in the studio for acoustic treatment

A professional grade studio, if you have the funds for it, would use

fibreboard, coirboard or gypsum panels, along with glasswool. Some studios

use a variety of angled wooden surfaces attached to the walls to control and

manage the sound reflections. Floors and ceilings in a professional studio

may also be built of absorbent materials like cork, mounted on a shock

absorbing frame supported on a dampening cushion of springs or rubber

runners. This kind of acoustic treatment needs to be installed by an expert,

and is usually quite expensive, being charged on a square foot basis.

However, a little understanding of how sound waves are reflected by surfaces,

along with a sense of invention can achieve a lot: A number of community radio

stations use simple low cost techniques to reduce the reverb in the studio.

To start with, it helps to have rooms that don't have continuous walls that

exactly parallel each other, because parallel walls create the most echoes. If

one of the walls has a staggered construction, with sections that are slightly

ahead or behind the other, this can cut down the reverb quite a bit. A simple

way to reduce the reflection is to attach something to the walls that reduces

the reflection of sound from them. The easiest and simplest way of doing this

is to acquire a large number of egg trays, the papier mache trays that eggs

are supplied in. If you have enough of these, you can physically paste them

over the entire wall, edge to edge, with any strong glue. The indented surfaces

and the soft material of the trays absorb and dampen the reflections to a very

great extent. (Make sure you treat the trays with a strong pesticide to keep

out cockroaches and other bugs).

Alternative low cost techniques are to paste foam sheet - 1.5" or 2" thick

foam sheet is best - across the entire wall surface, and cover it with cloth; or

to hang thick double panel drapes - velvet or any other fabric with a thick

pile work best - from floor to ceiling, with plenty of folds and ruffles in the

fabric to create a varied surface. Remember to put a carpet or dhurrie on the

floor, as thick as you can arrange; and to cover the ceiling with acoustic

material as well - floors and ceilings reflect sound too!

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It is worth exploring other low cost construction materials that are

used commonly in your area to see whether we can use them for

acoustic treatment: Many low cost studios successfully use materials

like panels of dried hay and porous clay attached to the walls; or

even rattan and bamboo screens made out of woven strips of cane or

bamboo!

A studio in Radio Toco, Trinidad & Tobago (Caribbean).

This one uses cloth and padding for the walls.

c. The recording floor/stage - control room partition: When we have a

single room setup, which combines the functions of both studios, there is

usually no separate recording space at all: Interviews, recordings and

broadcasts all happen within the same space. If at all there is a separate

recording space in this kind of a setup, it is usually if the form of a small

booth. This booth may be as small as a closet or cubicle. It generally has a

small door on one side and may accommodate one or two people.

On the other hand, when we have the luxury of a separate production

studio or a larger dual purpose studio, the studio space can be sub-divided

more clearly into a recording floor and a control room, as shown in the

three room studio diagram shown in Fig 2-5. In this case, by recording

floor, we mean the acoustically treated area where the microphones are

actually placed, and where guests or performers actually speak, sing or play

their instruments. Ideally this space should accommodate at least 3 - 4

people at a time, and should be paid greater attention from an acoustic

treatment point of view.

The control room, then, is the space where the producer or sound recordist

sits with his equipment and from where he/she guides the recording process.

In such setups, the partition between the recording floor and the control

room is of great importance, as it also needs to be factored in when planning

the acoustic treatment of the recording floor. The partition itself could be of

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solid brick and mortar, if you want to make it permanent. Alternatively, it

could be constructed of a wood frame and plywood, with thermocol or

glasswool in the gap between the two sides, for better sound insulation. The

door to the recording floor can then be built into the partition with good

quality plywood, and equipped with rubber gaskets to provide a good seal.

Fig 2-7. Double paned and one tilted glass pane partition

The greatest attention, though, has to be given to the window in the partition

between the two spaces: It is vitally important for the sound recordist or

producer to signal the people inside the studio during the recording process,

and this window is used for that purpose. It is often quite large, covering a

substantial portion of the partition, to allow one to see the entire recording

floor and - like the external windows in the studio (if any) - needs to be

double glazed, with non parallel panes and rubber or silicone mounted

glass panels, to avoid sounds from the control room entering the recording

space. It's a good idea to get a few packets of silica gel, a substance that

absorbs moisture, and place it between the two glass panels when you fit

them in place: This will absorb any moisture that would otherwise condense

on the inside of the glass if the weather grows colder.

4. Furniture

Once our spaces are broadly defined, it's time to think about the kind of

furniture that we'll need to utilize and operate in these spaces conveniently

and comfortably. And the key words to remember here are reconfigurable

and hard-wearing.

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It may also help to have an accurate idea of the equipment you are going to

install - especially the dimensions of mixers or monitors - before acquiring

any furniture or asking a carpenter to make them.

It is best to think in terms of furniture that could be mixed and matched in a

variety of ways so that we can adapt our setup to different needs. At the same

time, we need furniture that doesn't get damaged or scratched easily with

use, as we would like to keep our studios and offices looking good for

visitors even if they are constantly utilized all through the year.

The office space is comparatively easy to kit out, with a couple of desk spaces

(desks with drawers are to be preferred), some comfortable working chairs, a

filing cabinet (optional, a shelf or a cupboard will be fine) and wall space

where we can hang some pin boards and whiteboards if we need them.

The studios need more attention, especially the broadcast studio and the

control room. Traditionally, professional studios use a curved half moon

shaped (or broad vee-shaped) desk with the compere or recordist sitting in

the inner curve. This kind of a desk allows the compere/recordist to access

different pieces of equipment on all sides with a minimum of movement, an

important consideration when he or she may be talking into a microphone

even while he/she is operating the mixer, CD player or studio computer. But

depending on the space you have and the kind of equipment you are using,

there is absolutely no reason why any desk shape that fits cannot be used.

Just remember that:

(a) The desk should give you some working space along with any equipment

on it, so that you don't keep knocking expensive equipment off it every

time you move;

(b) Your studio chairs should be sturdy, should not squeak, and should be

comfortable enough to be occupied for extended periods of time;

that lets the producer/recordist look comfortably into the recording

floor space through the window without having to move or get up.

(d) The furniture should give you access to the back panels of the equipment

easily to be able to connect and disconnect cables, and so that you can

perform maintenance related tasks.

A readymade studio desk with space for mixer,

equipment and interviewer.

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Recording floors are generally equipped with a small 'talk' table, where the

interviewer sits with the interviewee(s). This is removable, of course, should

we decide to use the space for radio drama, when moving room will be

required.

It's also a good idea to equip the studios with plenty of shelf space, open

and with doors, to place pieces of equipment, cables, manuals, and related

stuff. Expensive equipment may need to be stored in a more secure metal

cabinet, or at least a shelf that can be locked. Equipment, especially if you

have higher end pre-amplifiers and patch boards, may require the making

or purchase of standardized equipment racks that allow you to fit the

equipment rack style one above the other. These racks are generally made

to standard heights in multiples of 44 mm (44mm, 88 mm and so on) and

483 mm/19" widths. The pieces of equipment designed to fit in them

subscribe to the same standard - like this:

44 mm

88 mm

483 mm

Fig 2-9. Standard rack mount

5. Electricals

Needless to say, setting up a community radio station means having adequate

access to electricity. It also means having to deal with a whole lot of cables

and connecting wires - microphones to mixers, recorders to mixers, broadcast

studio to transmitter, and so on - running between equipment and from

room to room. So it's wise to give this some thought in advance.

While it would be an asset to have someone who has an advanced knowledge

of electrical systems and wiring as part of the team, it's not very difficult to

Remember that furniture should not be a limitation: Almost any

furniture you can access can be used imaginatively to furnish your

station. A good carpenter can also help you design furniture that fits

the dimensions of your spaces precisely (something that may not

always be possible with readymade furniture).

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grasp the basic electrical setup that we will be required to deal with in a

community radio station. Given that we are dealing with expensive and

sensitive electronic equipment in a CRS, the value of a stable and risk free

electrical supply cannot be overemphasized.

To start with, it's a good idea to see that there are adequate electrical points

and outlets in each room, especially the rooms in which much of the

equipment is run. Points should generally be of the 3 pin line-neutral-ground

type, and electrical switches and points should preferably be from a reputed

manufacturer and be certified by a standards organization like BIS. This

ensures that the dimensions of the sockets conform to international standards

and that loose plugs and switch contacts (which could cause sparking) do

not result. Beware of counterfeit goods, which are plentifully available - so

don't just go blindly by the brand.

Wiring is the second concern: always check that high grade wiring - BIS

marked is highly preferable, as is fire retardant wiring - exists throughout

the station. (You may consider getting the wiring done anew if it is of poor

grade or undependable). Check that the distribution of power supply across

the station is even, especially where multiple rooms are concerned, and that

specific wire sets do not take the brunt of the load. 22/7 grade wiring is

acceptable for most uses, with 22/4 grade wiring preferred for heavy load

points. It is good practice to equip heavy load electrical points with the

larger 3 pin sockets (also called Power points or 15A sockets), which accept

the corresponding larger three pin plugs. Lesser load points can utilize the

smaller 3 pin (5A) sockets and plugs. You can decide where you need to

connect what equipment on the basis of the power consumption of each

piece of equipment.

While on this subject, you may also like to ascertain whether the supply you

have is three phase or single phase, with the former much to be preferred.

Three phase connections are more usually available in urban or semi-urban

settings, but offer the advantage of being able to distribute the loads you

place on the supply across the three phases. (Besides, power tends to be

available in one of the phases even in the event of a power cut, which means

we can always make arrangements to reroute our supply from the active

phase, if this is required.) Single phase, while being perfectly usable, does

not permit us these advantages.

The incoming supply should ideally be routed through an isolator, which

allows us to disconnect the entire wiring system from the main supply at any

moment) or a large load MCB (miniature circuit breaker, a spring loaded

switch system that trips or shuts off the supply if the load exceeds a certain

value or if there is a short circuit of any kind). An ELCB (or Earth Leakage

Circuit Breaker) is also a wise choice, as it is a device that automatically cuts

off the power if there is a short circuit, or if there is an accidental contact - like

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someone coming in contact with a naked wire, for instance. Each point (or

set of points and switches, as the case may be) should then be connected to

individual MCBs of an appropriate rating, to enable us to cut off supply to

individual problem areas for maintenance. The entire combination of ELCBs,

isolators and MCBs should be mounted in a safely sheltered but accessible

circuit box somewhere near the entrance of the station: Circuit boxes are

available in several readymade sizes in any large electrical market and contain

a metal rail system on which individual components can be mounted.

Also check the approved load available from the a/c (alternating current)

mains supply: The original paperwork for the electricity connection should

contain this information. If not, you can examine the record at the local

electricity office. This should usually be given in KW (Kilo Watts, multiples

of a 1000 Watts). Compare this with an estimate of the total consumption of

the equipment you will be installing. Try and ensure that your 'load' never

crosses 2/3rds of the total approved load. (For example, if you have an

approved load of 5 KW, try to see that the sum total of all appliances, even

the ones that aren't on all the time, doesn't exceed 3.5 KW. You can exceed

this self-imposed limit, of course, up to the total rating, but it's a good idea to

have some headroom and not strain your wiring too much).

If you feel your load may exceed this or approach your approved load, see

if it might make sense to increase the approved load officially and get a

greater electrical supply. You will need to apply to the local branch of the

A typical three phase electrical isolator unit.

The unit allows the connection of three phase wires

and the neutral wire.

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electricity department for this. Please note that rentals for electrical supply

are based on KW slabs and that - depending on your location - there may be:

(a) a limit on the maximum approved capacity that you can obtain;

(b) a distinction between residential and commercial connections, with

sharply higher rentals for the latter; which may make a difference to your

operational budget;

Finally, where electricals are concerned, we have to plan for backup supply:

Transmission and production work cannot be interrupted if your primary

energy supply fails for some reason. It is therefore wise to invest in a battery

based backup system like an inverter, which will at least support the key

equipment that cannot be shut down - especially the transmitter. Inverters are

Calculating appropriate ratings for your main power board

To select the correct rating for an individual MCB, first ascertain the

consumption of the equipment or fixtures that you will be connecting to

it: Most equipment manuals will tell you the consumption in Watts, and

items like bulbs and fans are usually marked with Wattage figures. Use

the formula:

W/V = A

where W is the consumption in Watts, V is the voltage of the system in

Volts (usually 220 Volts in India) and A is the current drawn in Amperes,

to calculate the corresponding current draw through the MCB. MCBs

are marked with the maximum current draw in amperes that they will

accept before tripping, with 6A, 10A, 15 A, 20A and 32 A being quite

common. Select an MCB that exceeds the Amperage of the fixtures and

equipment you intend to connect to that specific MCB: Keep an eye on

the future, and select one that can accommodate a couple of extra

pieces of equipment if need be. ACs and heavy draw equipment will

need higher capacity MCBs, while all the lights and a couple of fans in

a room may need a single 6A MCB.

Sum up the Amperage of all the equipment and fixtures on all the

individual MCBs to arrive at the appropriate rating for the master isolator,

MCB and/or ELCB (40 A and 63 A are the most common types, and

should be fine for most setups). MCB and ELCB installation may require

some electrical expertise, so consider this before starting any

installations.

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A typical CFL bulb. CFLs consume very

small quantities of electricity to provide as

much or more light than equivalent

incandescent (tungsten) bulbs.

also available in various capacities and ratings - the 650 VA, 1250 VA and

1500 VA are the most common. VA is analogous to Wattage, a term we are

already familiar with.

Inverters can be acquired in single battery or multiple battery configurations

for extra storage. They are charged from the mains electrical supply, so an

important consideration, again, is whether there is enough continuous main

electricity supply to keep the batteries charged against power cuts. It is also

wise to remember that the storage capacity is linked to the cost of the unit, and

that the battery units - usually 25 or 27 plate automotive or tubular batteries -

need to be replaced roughly every two years. (Most of these batteries are of the

lead-acid type and need a topping up with distilled water and/or acid at

regular intervals. Maintenance free batteries, which need no topping up, are

also available, but are more expensive.)

The more expensive - but more independent - backup is an electrical

generator set, with a motor which runs on kerosene, diesel or petrol.

Available in a variety of ratings from 650 VA to several KVA - the larger ones

are run on diesel - they allow you to operate in areas with no power supply

at all, or during extended power cuts, but require a continuous fuel supply

and regular maintenance. The noise they make - even the sound insulated

ones make some noise - and the exhaust gases can also be a concern.

For more on generators see Section B: Generators on Page 229

It's also a good idea to economize by using more energy efficient lighting

fixtures (compact fluorescent lamps or CFLs). instead of standard tube-

lights and tungsten incandescent bulbs, for instance), natural ventilation

systems (better insulated walls for heat and cold protection instead of coolers,

fans and heaters) and alternative energy supply systems.

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Alternative energy systems like solar power (which converts sunshine into

electrical energy) or wind power (which uses the wind to move turbines

which generate electricity) can be a great cost saving in the long run - and

are eco-friendly as well. Though the initial installation costs are often very

high, if you can invest in these systems, they are more than likely to pay for

themselves within a few years. In places where mains power is very intermittent

or suffers frequent breakdowns, these can be very viable systems to consider,

as they allow your station to operate without any interruptions of service.

A solar panel array. Typically, a smaller setup would

need only a few panels (or a single medium sized panel)

to fulfill some of its energy needs.

The last, but not the least, thing we need to remember is to ground or earth

the entire electrical supply and wiring of the station.

Practically, this means providing a safe route for the absorption of electricity

leaking in the system, as well as a creating a zero potential against which

reference electrical voltages in the system may be read. As we shall see later

in the manual, this is of special significance for the antenna tower, which is

often prone to lightning strikes. But where the station and studios are

concerned, grounding is important for two reasons:

a. To allow the ELCB to work, since the ELCB breaks the circuit when it senses

the sudden flow of current into the earth through the accidental contact;

b. To prevent leaking currents from damaging sensitive electronic equipment

(the shock you sometimes feel from a television or the metal surfaces of

any electric/electronic device is usually due to poor grounding); and

c. Poor grounding often leads to a hum that can be heard over the audio

cables in the studio, caused by the cyclical nature of the a/c mains supply.

A good compromise with alternative energy systems is to use them to

power only certain sections of the station - just the lights, say, or the

transmitter and playout system - so that you can keep the load on the

alternate supply low, and incur a lower initial cost. Keep in mind,

though, that this may involve revisions of your wiring, though, to allow

the alternate energy system to supply only select pieces of equipment.

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This is often accompanied by electromagnetic interference from the

Earth's magnetic field and transmission lines, which can also be addressed

by good grounding.

3- wire branch

Service entrance

Sub panel

circuits

Fig 2-10. Grounding equipment is an important consideration for CR stations.

Most modern electronic systems are susceptible to faults caused by poor grounding.

Typically, in the absence of a formally wired ground, grounding can be achieved

by simply running a wire connected to the ground points of all the power

outlets and connecting it to any buried water pipeline made of metal (especially

the galvanized iron or GI main water supply lines found in most places.)

A more through professional grounding is to be much preferred, however,

and involves the connection of the ground wire to a buried copper

conductor plate. The size of the plate is worked out on the basis of the total

estimated load on the supply and the plate is buried at a depth which

guarantees enough moisture to ensure good conductivity. This is often

improved by burying the plate at that depth in a bed of charcoal and salt,

which makes for better conductivity; and by leaving a channel or pipe

buried alongside to allow the periodic addition of water to keep up the

moisture levels.

Again, the importance of good grounding cannot be over-emphasized, as

the safety of very costly electronic equipment in the station is dependent

on this.

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1. Routing Equipment wires and cabling

While designing the spaces and studio setups, it is also important to decide

where and how you will route the numerous cables that connect the

equipment together. Many of these wires and cables will actually connect

different spaces together and we must think about how to organize and

route them to avoid tangles and provide for easy upkeep and maintenance

and to ensure that the cables are not accidentally damaged during general

use, by rats or other vermin.

For more on cables and connectors see Section B: Connectors (Power) on Page 163

and Section B: Connectors (Audio & Telecom) on Page 166

The first requirement is cable ties, which are flexible binders made of nylon,

and available in electrical and computer stores. There are reusable and single

use varieties. Cable ties can be used to gather sets of related cables and tie them

together; many cable ties have a space for you to attach the tie - and thereby the

gathered cables held by the tie - to the wall or to the back or underside of furniture,

which keeps things from getting messy and allows easy cleaning. In a pinch,

these can be substituted with twists of wire cut to size or stout twine.

A selection of cable ties. The tip is looped around the

cables that need to be tied together and through the box

at the other end of the tie, which locks the loop in place

The second option is to fit plastic cable channels or cable trays to walls, just

above the skirting, through which cables can be routed to keep them from

coiling all over the floors. Cable trays have perforations around their entire

length, and a sliding plastic cover, so that we can add and remove cables at

will with very little effort.

Where cables pass from one room to another - between the recording floor

and the control room, say - we must make special provisions, especially if

acoustic treatment of one of the spaces must be respected: Cables must be

routed through prepared channels or spaces designed in the partitions,

preferably with a system of baffles or a rubber diaphragm around the cables

to make an airtight seal.

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Professional studios and auditoria are designed with these cable routing

exigencies in mind, and include under-floor channels and concealed wall

panel fittings for connections and wires. If these are feasible in your spaces,

they are excellent methods to keep cables out of the way.

A short note on flexibility

While planning and designing your station, always think about how

you can rearrange your setup to meet future needs: Accommodate new

equipment, for instance; or even move the entire setup to a new location.

All too often, CR stations have to upgrade or replace equipment, in

which case a lack of planning means you are stuck with furniture or

spaces which will now not go with the new equipment.

Keep the setups as modular and easy to dismantle as possible, to allow

quick swaps and switches to be made. Some items, like soundproofing

or partitions may be harder to change or shift - but that's unavoidable.

The more you plan for this in advance, the easier it will be to make

changes without seriously disrupting the station's activities.

Never let equipment and mains power supply wires overlap

cables carrying audio between equipment. The electrical

supplies may cause interference.

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A radio programme being broadcast by

Radio Madanpokhara in Nepal. The studio

dimensions are small, but the space has

been utlilized creatively.

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TECHNOLOGY - II

STUDIO EQUIPMENT

Chapter 3

In the previous section, we discussed the division of the station's studio

work between the production studio and the broadcast studio. Continuing

on the same theme, let's have a look at the kinds of equipment that go into

the working of each of these studios.

There are many items which may be common to both studio setups: A two

studio setup would need one each of these pieces of equipment, but a

single studio setup would (obviously) require only one.

A second consideration is that modern computerized systems can often use

different kinds of software to perform functions that would otherwise require

a wide variety of studio equipment: For example, there are now different

softwares available for editing, mixing, and mastering audio which can all

run on a single computer. This may help you avoid acquiring some of the

studio equipment outlined in this chapter.

For more on editing/mixing software, see Section B:Computer Software on Page 159

Relying on a single computer for all your studio functions could

hinder your production and broadcast process if the computer fails

or requires maintenance!

These descriptions do not include details of the cables and connectors

required in the two studios, as that varies from equipment manufacturer to

equipment manufacturer.

For more on cables and connectors see Section B: Connectors (Power) on Page 163

and Section B: Connectors (Audio & Telecom) on Page 166

Section I: The Broadcast studio

The broadcast studio typically has an equipment setup something like

Fig 3-1.

Let's look at each piece of equipment step by step, to understand its function:

1. Microphones: Typically, the broadcast studio should have at least two

high quality voice mics - one for the compere/host/presenter, and one for

the guest. (A third would be good value if it is affordable, allowing a second

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guest to be 'miked' separately (and thereby, his/her audio levels controlled

independently) as well as giving the studio a spare mic.

For more on microphones see Section B: Microphones on Page 198

The mics are typically not powerfully directional, as the studio already has

controlled acoustics, and the speakers are quite close to the mics. In some

cases, there may be a single mic which has a pickup on both sides, which is

then shared by the people on either side of it.

Shure SM 58 dynamic microphone

Fig 3-1. Schematic diagram of a broadcast Studio setup

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The mics are also usually mounted on adjustable stands - in the case of the

compere's mic, often on a swinging armature that allows for very precise

adjustment of the mic position. This is so that so that the speakers do not

need to hold the mics in hand, and also so that the mic stays at a constant

distance. Speakers tend to have different speaking voices, and tend to be of

different heights, so ease of stand adjustability is an important consideration.

Good studio mics include the Shure SM 58, the Behringer TSM 87 and the

Rode NT-1A. Very high end mics include the Neumann U87 and the

Sennheiser MD 421. Indian mics include those manufactured by Ahuja

Radio, which supplies a variety of mics for different purposes. Nowadays, a

number of very economical microphones made in China are also available

in the market quite easily.

A Neumann U 87 condensor studio

microphone. Note the suspension shock

mount that holds the microphone and

prevents accidental movements of the

mic from causing a rumble in the audio.

Stands are available from a variety of suppliers, and in a pinch, even locally

manufactured stands will do, as many of the mics come with appropriate

grips that fit on top of the stands. Sometimes, but not often, mic manufacturers

provide stands specific to their mics.

It is important to select mics according to the function they must

perform, and so that they meet the appropriate quality standards that

are required for radio transmission. Select mics that have a reputation

for sturdiness; and which will not fail at key times.

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2. CD players: The current standard for playback sound sources - especially

for music - is the CD player (though DVDs and their most recent cousins,

the Blu-Ray disc and HD DVD, are the recent rage in the video world.) Two

CD players would be very useful for a broadcast studio, allowing pre-

recorded materials to be smoothly mixed with each other without gaps in

transmission.

A mid range CD player from Denon, with a matched

amplifier unit. Mid range home music CD units are often a

good option for CR stations.

Studio CD players should have large displays so that they can be read from

a distance, and should preferably be controllable from the mixer, which

makes them easy to use (though this is not vital). Most importantly, they

should allow you to connect them to a professional grade mixer unit with a

balanced connector. They are one of the workhorses of any station setup.

Good studio CD player units are available from Denon, Sony, Tascam and

Pioneer.

For more on CD players see Section B: Compact Disc Players on Page 141

3. Studio cassette deck: The cassette deck, which plays audio cassettes, is

still a staple of many radio setups, since a lot of recorded material - especially

music - is still available on cassette. Usually, any good home cassette deck -

especially those from Denon, Sony or Pioneer - can perform this function,

but a professional deck provides the advantage of balanced outputs for

connection to a mixer. A dual tape deck, which allows you to use it as a dual

cassette source for mix purposes is an added benefit. The Tascam pro units

are of good grade and take heavy studio use.

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The Tascam 322 dual cassette deck, a popular studio deck.

Note the flanged edges that allow it to be mounted in a rack mount.

For more on studio cassette decks see Section B: Cassette Tapes & Cassette

Recorders on Page 134

For more on balanced connectors see Section B: Balanced & Unbalanced

Connectors on Page 131

4. Recorder unit(s): There is actually a wide variety of studio recorder units

now available to choose from. Till a few years ago the recorders of choice -

and still popular in many places - were the Digital Audio Tape (DAT) recorder

(which records digital audio on magnetic tape at very high quality) and the

MiniDisc (MD) recorder (which used small magneto-optical disks somewhat

like small CDs, and also records broadcast quality audio). Today, flash

memory based recorders recording on solid state memory like SD (Secure

Digital) cards and CF (Compact Flash) cards are rapidly becoming the norm.

Two popular units, equally at home in a studio or in the field because they

are so compact, are the Marantz PMD 670 and the Edirol R-09. (There is a

Marantz PMD 660 as well, which is an even smaller version of the PMD

670.) A number of studios have also moved to purely computerized units

where the audio is recorded digitally directly on the computer's hard disk.

PIC- 3.4

Marantz PMD 670 solid state recorder.

The recorder records on Compact Flash (CF) cards.

For more on Flash recorders see Section B: Flash Recorders on Page 187

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5. Mixer : A good mixer is the heart of the studio, allowing you to combine

a variety of inputs and manage the audio levels of the various sources and

mics. Each of the sources is connected to a separate channel for independent

control, each of which has a sliding fader that allows you to raise or lower

the level of the audio signal feeding through that channel.

A Mackie 4 channel mixer unit.

Note the four white channel faders

at the bottom left of the mixer.

The number of sources and mics you have in the studio usually decides the

number of channels you need on the mixer - but 4 to 8 channels should be

fine for most mid level stations. Prime considerations are the quality of the

sliders (the moving resistors of the fader units); and the options for controlling

all the other studio equipment - decks, CD players and mics - from the

mixer itself. Good broadcast mixers are available from Behringer, Mackie,

Sony, Soundcraft and Tascam. (In case a broadcast mixer with such controls

is not available, a production mixer may be substituted instead, with the

other sources and controls operated manually.)

For more on production mixers see this chapter's Section II on Page 54

6. Headphones and monitors: The usual rule is to have a pair of headphones

for each speaker in the studio. The headphones are used to monitor the audio

going on air and to preview a new source before its sound is actually mixed in.

Using headphones is especially important in the broadcast studio,

because speakers would feed back sound into the mics, creating a loud

whine or howl called acoustic feedback noise or 'howlround'. (Some

studios use speakers and a switching system where the on air audio is

heard over the monitor speakers, which cut off the minute any of the

mics become active.)

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A pair of Sennheiser high quality headphones.

Note the padded ear cups designed to fit snugly

on and around the wearer's ears.

Good headphones are available from Behringer, Sennheiser and Sony.

Good studio monitors are available from Behringer, Sony, KRK, Denon,

and Tannoy, with the last three being very expensive pro studio options.

For more on Headphones see Section B: Loudspeakers & Studio Monitors on

Page 190

7. Distribution amplifier: The Distribution Amplifier is another important

piece of broadcast studio equipment. It boosts and amplifies audio from all

the sources - audio players, mics - and feeds them to the recordings units

and to other studios if necessary.

For more on Amplifiers see Section B: Amplifiers on Page 128

A Behringer 4-headphone audio amplifier.

The unit is used specifically to distribute sound to

upto 4 headphones with no loss of signal.

8. Pre-amplifiers and amplifier units: Several source units may have very

low signal outputs which need to be amplified by pre-amplifier units that

boost the signal to a level comparable o the remainder of the sources. Also,

the outputs going to the headphones, the transmitter or - more usually - the

studio monitor speakers may need to be boosted by an amplifier unit.

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Whether these units are required or not depends on the precise configuration

of your studio setup.

For more on Amplifiers see Section B: Amplifiers on Page 128

9. Telephone hybrid or caller input: One of the best ways to get your

listeners involved in the programme is to give them an opportunity to call in

during the programme, so that they can also participate in the programme.

To get your callers on air, we require a telephone hybrid unit - there's

usually a hybrid unit available to connect almost any type of telephone to

the mixer unit, but it's important to first think about how many telephone

lines you may have for callers to call in on: Large professional stations have

dozens of lines for callers, but a smaller CRS may have only one, which

considerably simplifies the job of selecting a hybrid unit. Some stations get

around the need for having a multi line hybrid by connecting their office

EPABX intercom system to their mixer, and using their dual or multi-line

capabilities to enhance their call-in facility.

A Sonifex telephone hybrid unit

A simple way to connect callers to the studio setup is to use a phone

line connected to a speaker phone unit: Incoming calls can be played

over the speaker phone, with a mic placed close to the speaker

phone to pick up this sound and feed it to the mixer unit. With this

technique, it is important to avoid audio feedback, which could

cause a whining noise in the audio.

For more on telephone lines, see Chapter 6: Telecommunication & Other

Ancillary Equipment on Page 81

For more on Telephone Hybrids, see Section B: Telephone Hybrids on Page 220

10. The On-Air light: In order to effectively signal that the studio is in use and

broadcasting ('live'), the usual system is to have a red 'On Air' light inside

and outside the studio, that can be activated when work is going on. The

inside light then tells guests that the broadcast is taking place, and the outside

light tells people outside the office that the studio is busy. High grade on-air

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The On-Air light can also be a simple switch operated light that can

be turned on just before broadcast begins or when the stusio is in

use. It just takes a bit of discipline to build this into the standard

operating procedure for anyone working in the studio.

lights are activated automatically when the mics are live, and are connected

to the mixer unit.

Several simple software meant to play back audio on a computer in

a particular sequence can be substituted as basic playout systems:

Just complete your programmes, compile them into a playlist using

free software like WinAmp, and press 'play'!

For more on playout systems, see Section B: Digital Playout Systems on Page 173

12. Broadcast recording devices (Audio Loggers): As part of the monitoring

and grievance redressal mechanism, many governments and adjudicating

bodies make the recording and storage of all the programmes broadcast over

a given period of time preceding any given date mandatory. In India, it is

mandatory to record and store each programme for a 3 month period from

the date it is broadcast: This is so that the programme may be produced before

the adjudicating committee if someone files a complaint about the content.

For more on CR broadcast regulations in India, see Chapter 9: CR Guidelines

in India & their Implications on Page 105

This means, naturally, that we have to record the programmes on a continual

basis, and have enough storage capacity to store three months worth of

programmes at any given time. This is not a very great problem if your

station only broadcasts one or two hours in a day - which would add up to

90 days x 2 hours = 180 hours of programmes. But a station broadcasting

8 hours every day would have to store 8 x 90 = 720 hours worth or

programmes!

11. Computerized playout system: When we have a variety of live and pre-

recorded programming being broadcast, it's often a little difficult to cue the

programmes manually in a seamless and uninterrupted fashion. With

computer systems becoming cheaper by the day, a number of small radio

stations have increasingly begun to rely on computer based playout systems,

which automatically play programmes in the correct sequence without human

intervention. In some ways, this is a luxury for small station, but the potential

savings of time and effort are enormous, as this would avoid having a variety

of playback systems in the studio: The programmes, whether they are on

cassette, CD or any other medium, are transferred onto the computer first,

which then becomes the only 'source' unit in the studio. Professional playout

systems like Enco often require specific hardware to work. There are also

free alternatives like Zara Radio and Campcaster.

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The amount of programming you have to store to comply with the regulations

really decides what kind of equipment you will store the broadcasts on: If it

is comparatively little, you may decide to record the programmes on cassette

tapes - it may take just a couple of cassettes to record two hours of

programming a day. The cassette recorder can be connected to the broadcast

chain in parallel with the transmitter, so that it receives the same signal that

will finally go out over the antenna.

If the programming is greater than that in quantity, it is wise to set up a

dedicated computer with a large hard disk based storage capacity to record

the programmes in a suitable format. If space on the computer's internal

hard disk is limited, the recordings can be regularly transferred to CD, DVD

or an external high capacity hard disk from the computer's internal hard

disk. (With memory and hard disk prices coming down so sharply over the

last couple of years, it is now relatively inexpensive to install a suitably large

hard disk within the system itself.) The programmes so recorded must be

clearly labeled with the programme name and the date of broadcast, which

should also be marked on any external media that are used - CDs or DVDs

for example - so that there is a clear record of the broadcast content.

13. Satellite receiver: A new addition to the bank of source units is the

satellite radio receiver, which receives radio signals directly from a satellite,

like a DTH (Direct to Home) TV system. There are two or three satellite radio

services providing a variety of music and programming available in South

Asia, with the most prominent being the Worldspace Radio system. If you

feel you can use the programming to pad out and fill in certain programming

needs, it may be useful to acquire a satellite radio receiver, and work out a

rebroadcast deal with the service provider. The upside is the availability of

plentiful and CD quality programming. The downside is that the programming

may not be relevant to your audience; may be mostly music based; and that

your station will have no control over what's coming in and being rebroadcast.

A Hitachi Worldspace satellite radio receiver unit.

The line out socket can be connected to the mixer.

14. Optional: Other playback source units (DAT, LP players, spool players)

As noted before, CD players, solid state recorder/players and computerized

playout and playback systems have made rapid strides in recent years, and

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have all but replaced older warhorses like the vinyl record or LP player; the

spool (or reel-to-reel) player/recorder; and even the comparatively recent

DAT recorder/player. If you feel that any of your source materials may still

be in any of these formats, you should consider whether you need to acquire

any of this equipment for your station.

Since most modern audio systems are digital, it makes sense to transfer

older recordings on tape or LP records into a digital format that can be stored

and played back on a computer or flash recorder unit in the long run.

Section II: The Production studio

The first thing to remember is that the basic setup of a production studio is

not very dissimilar to a broadcast studio (and, in fact, that's the idea, because

it gives us the flexibility of using it as a backup broadcast studio!) But the

choices we make of the numerous options of each type of equipment may

sometimes be a little different.

The primary difference is that it is not directly connected to the transmission

system, and that it is generally equipped with equipment that allows you to

Fig 3-2. Schematic outline of a production studio setup

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record and edit programmes for later broadcast. The second difference is -

as we have seen - that the production studio is usually equipped with a

formal control room and recording floor spaces.

The production studio typically has an equipment setup something

like the one shown in Fig 3-2.

Once again, let's look at each piece of equipment step by step, to understand

its function:

1. Microphones: Like the broadcast studio, microphones are an integral

part of the production studio. They will usually be set up in the recording

floor area, and the preference in production studios is often for mics that

have a bigger pickup area, usually all around the mic itself, as we often use

the production floor for discussions involving three or more people; or for

radio drama that may mean several voices talking at once.

Unlike the broadcast studio mics, though, the mics in the production studio

may not necessarily be on stands - often they are placed on the 'talk' table

placed in the production floor, equidistant from all the speakers, or

suspended from above in the middle of the recording floor, so as to enable

people to stand or sit around the microphone. However, depending on

what you are producing, there may be a variety of specialized mics used

individually or simultaneously - including highly specialized mics that may

be used to record individual musical instruments. But good mics, remember,

are expensive - and while the temptation to equip yourself with a number of

mics is always there, you must consider what selection of mics is affordable

within your budget - and what kind of recordings you will be doing most of

the time. (Obviously it makes no sense to buy an expensive professional mic

that is designed to record a percussion instrument well if we will actually be

recording panel discussions and human voice most of the time!)

The Samson C-01 condensor mic.

This type of mic is especially useful where

you have more than one performer around

the mic, as in radio drama.

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To our previous recommendation of the the Shure SM 58, the Behringer TSM

87 and the Rode NT-1A - and the Neumann U87 and the Sennheiser MD 421

- we might add the AKG C 414, the AKG C 3000 and the Samson C01.

For more on microphones, see Section B: Microphones on Page 198

2. CD players: Since prerecorded programs mean that you may be mixing a

number of different sources into the final programme, a good broadcast CD

player is an asset to the production studio. (However, this could be substituted

with a more affordable home CD player as well, as reading the display of the

unit from a distance is not a primary concern here. A home CD player would

not have a balanced professional output, but that can be worked around if

you are on a tight budget.)

Good studio CD player units are available from Denon, Sony, Tascam and

Pioneer. Good combo drives (CD writer + DVD-ROM) or DVD-Burners

(Superdrive) are made by Sony, Liteon, Samsung and LG.

An HP internal combo drive unit that plays DVDs and can read and write CDs

A useful solution is to have a good quality DVD writer, CD recorder

or CD player built into the computerized editing and post production

unit (see below), which will allow you to 'rip' tracks from CDs directly

in digital format, thereby preserving their quality.

For more on CD players see Section B: Compact Disc Players on Page 141

3. Studio cassette deck: Once again, a good cassette deck is vital to the

production studio. Cassettes are still the primary way to store pre-recorded

materials in many portions of the country, especially the rural areas; and

cassette players are therefore still in abundant use. CR setups that intend to

distribute copies of their programmes to the listening public - and especially

those that also have outreach projects where programmes are 'narrowcast'

(played off portable cassette decks to small listening groups) - may pay

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A Tascam studio cassette deck. Note the VU meters at the top right

which help you adjust audio levels while recording.

Smaller CRS with tighter budgets may also skip having a computerized

(digital) setup altogether and use two cassette decks in the production

studio - with or without a mixer - for cut-to-cut (start and stop) editing.

This is the simplest and most basic way to edit - by dubbing the

portions we require section by section onto a second tape.

special attention to this need, and install more than one, to allow quick

dubbing of programmes. As noted before, the Tascam pro units are of good

grade and take heavy studio use.

For more on studio cassette decks see Section B: Cassette Tapes & Cassette

Recorders on Page 134

4. Recorder/audio storage unit(s): Besides the studio cassette deck, you

must decide what your final programmes will usually be stored on - that is,

in what format. If they will be stored on CDs or DVDs, the CD-burner or

DVD-burner unit which you will include as part of your computer editing

system will do fine. On the other hand, you may decide to store or write your

final programmes to DAT (in which case you will need a good studio DAT

recorder from Tascam, Denon or Sony), or MD (in which case you will need

a good MD recorder from Sony or Sharp). Studio MD models are hardly

available anymore, but Sony Hi-MD field recorders - Hi-MD is the updated

MD format - are still available at some outlets.

For more on MiniDisc recorders see Section B: MiniDiscs & MiniDisc Recorders

on Page 204

Finally, you may also decide to store and write final programmes to the

editing system's hard disk drive (HDD) itself, in which case you will probably

need several high-capacity HDDs in your system, to store a lot of audio.

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A large capacity external hard disk unit is a useful way

to back up your files and your complete programmes.

Such disk storage units may connect to the computer's

USB port or Firewire port.

PIC- 3.14

Remember that storage technology changes every day, with newer

audio formats and higher storage capacities emerging all the time!

It is usually good practice to store the recorded 'raw audio' and the final

version of the programmes on an external HDD of very high capacity: 750GB

and higher external storage units are now quite common. Keeping these

backups on an external HDD ensures that your DAW's internal memory is

always available, and also that your finished programmes are always safe if

your DAW fails for some reason.

A comparison of various audio storage media

Format Medium Capacity Interoperability

Hi-MD Hi-MD/MD disc 300 MB/1 GB Hi MD can record and

(26 mins/ playback in MD mode,

125 mins) but not vice versa.

CD Compact Disc 700 MB/80 CD-RW may not be

(CD-R, CD-RW) mins read in all CD players

DVD Digital Versatile 4.7 GB Writable DVDs may not

Disc (DVD) (DVD- be played back in all

R/DVD+R/DVD- DVD players. Most

RW/DVD+RW) DVD recorders can also

record on CDs

Blu-Ray Blue Ray disc 25 GB/50GB Some Blu-Ray

recorder/players may

also play back DVDs.

Not compatible with

HD-DVD, though

some newer players

can play both formats.

Contd...

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Format Medium Capacity Interoperability

HD-DVD HD-DVD disc 15 GB/30 GB Some HD-DVD players

will also play back

DVDs. Not compatible

with Blu-Ray, though

some newer players

will play both formats

HDD Magnetic storage Current Can store all digital

(magnetic platters highest: 1.5 TB audio and video

inside HD casing) formats. Highest

capacity. Only needs

appropriate operating

system and software to

play back contents. Can

only be used with a

computer. (Some newer

home video/audio

recorders have HDDs

built in for their higher

storage capacity).

5. Mixer : Once again, a good mixer is the heart of the studio, allowing you

to combine a variety of inputs and manage the audio levels of the various

sources and mics. Each of the sources is connected to a separate channel

for independent control, so the number of sources and mics you have in the

studio usually decides the number of channels you need on the mixer - but

a 4 - 6 channel mixer should be fine for most mid level stations. Prime

considerations are the equalizer controls (which let you control the tone

and quality of the audio); the pan controls (which allow you to mix in

stereo); the gain controls (which let you boost the inputs and match them to

each other; and the sliders/faders.

The Behringer UB 502 2-channel mixer. Decide the number

of channels and controls that you will require on your mixer

on the basis of the equipment you will connect to it.

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Experienced recordists and sound engineers would also like the ability to

group sets of inputs together to be controlled by a master fader. Good

mixers, as mentioned before, are available from Behringer, Mackie, Sony,

Soundcraft and Tascam.

Resist the temptation to acquire huge commercial or pro studio mixers

with 24 or 60 channels - you probably won't need them, and they

are fabulously expensive!

For more on mixers see Section B: Mixers & Mixing Desks on Page 207

5. Headphones and monitors: Production studio monitors usually need

to be of better quality than those in the broadcast studio, because one

tends to monitor the audio in the latter more over headphones. Good

quality monitor speakers from Behringer, Sony, KRK, Denon, and Tannoy

- especially the last three - can be very expensive, and it's okay to settle for

a lower grade of monitor speaker as long it doesn't buzz or crackle at

relatively higher volumes, and gives you an output that sounds reasonably

close to the original sound.

Listen to a lot of speakers and choose them according to your budget

and your own ability to distinguish between their quality. (In many

cases, where the production studio is equipped with a computerized

production and editing system, CR stations use good quality computer

speakers from Cambridge Soundworks, Logitech or Creative as the

studio monitor.)

A Creative Labs 2.1 computer speaker set with

subwoofer. Good quality computer speakers can often

be used as audio monitors in low cost CRS setups.

It is also wise to have three or four headphones - and the corresponding

outputs from the mixer, which may require a separate headphone amplifier

- in the control room; and two or three headphones in the recording floor

area, to allow singers or performers to hear a beat track or instrumentals

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Remember that most of the programmes a CR station makes are likely

to be heard in noisy situations on relatively inexpensive transistor

sets - so even though it is always nice to make a programme that has

very high production standards, very fine sounds and subtle mixing

are probably never going to be a priority.

while they are singing. Headphones may also be used for the talk back

system (see below.)

M-Audio ‘Audio Buddy’ pre-amplifier,

a low cost unit with two mic inputs

For more on headphones & studio monitors see Section B: Loudspeakers &

Studio Monitors on Page 190

For more on headphone amplifiers, see Section B: Amplifiers on Page 128

6. Distribution amplifier: Ideally, the production studio needs a distribution

amplifier as well, to feed the main output to the recording units (this may not

be necessary if the entire process is oriented around a computerized editing

system) and to the broadcast studio.

For more on Amplifiers see Section B: Amplifiers on Page 128

7. Pre-amplifiers and amplifier units: Once again, consider amplifier units if

there are several source units, many of which may have very low signal

outputs which need to be amplified by pre-amplifier units. Also, the outputs

going to the headphones, and the studio monitor speakers may need to be

boosted by an amplifier unit. (Some studio monitor speakers may have their

own amplification systems built in, in which case they are likely to be very

expensive indeed!). Whether these units are required at all - and if they are,

what kind are required - is dependent on the precise combination of

equipment in your studio.

For more on Amplifiers see Section B: Amplifiers on Page 128

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8. Telephone hybrid or caller input: It's also a good idea to have a telephone

hybrid system that feeds into the mixer unit in the production studio - this

allows you to pre-record telephone calls and edit them if necessary, an

undeniable advantage over the live call. However, many CRS prefer to equip

only their broadcast studios with telephone hybrids, as the immediacy of a

live call is often seen as more vital to audience participation than a recorded

and pre-edited phone call.

For more on telephone hybrids, see Section B: Telephone Hybrids on Page 220

9. The On-Air light: Production studios are also well advised to install an On

Air light, with lights in the control room, outside the studio door and in the

recording floor area, in order to advise guests in the studio and workers in

the office outside that the studio is recording.

10. The computerized editing system or Digital Audio Workstation (DAW):

Increasingly, production studios - and this applies to small CR setups

as well - are oriented around a Digital Audio Workstation, which acts

as a hard disk based recording system as well as an editing setup.

When we say computerized editing system, we mean, of course, a

computer equipped with the hardware to speedily and accurately

process audio data, and store and retrieve several fairly long (30 minute

and more) programmes simultaneously; and equipped with the software

to access, play back and edit audio data. Very well equipped DAWs are

no longer the preserve of expensive professional studios. A very good

system that is more than adequate for any high grade work by a CRS

can actually be assembled from components obtained from any

reasonably equipped computer parts market, by someone with a fair

knowledge of computers.

Modern audio workstations use software like Adobe Audition that let us

perform audio edits and sound manipulation. Freeware and open source options

have brought these costs down sharply of late.

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The primary considerations for a DAW are:



Processor speed



Hard disk capacity



Good motherboard with plenty of inputs and outputs



High quality sound card, ideally with a 'breakout box' that lets you connect

balanced outputs from the mixer



A good quality monitor (as large as is reasonable: 17 inch is good, 15" will

do in a pinch)



As much Random Access Memory (RAM) as can be afforded (512 MB

minimum)



Audio editing software (proprietary or open source, freeware or paid,

there are many excellent options)



Ability to connect a variety of field recorders directly to the DAW for

transfer of audio

For more on computer hardware and software, see Section B: Computer

Hardware on Page 152 and Section B: Computer Software on Page 159

13. Talkback system: Since the production studio must interact with the

people in the control room while recordings are going on - and it's not

always feasible to keep opening and closing the access door in the partition

between them - it's advisable to arrange a talkback system between the two

spaces. This is usually setup with a dedicated 'talkback' box that is connected

to a small mic near the mixer console on the control room side, and a small

speaker or a headphone set on the recording floor side, so that the recordist

or producer can give instructions to the people inside the recording floor

area. (On the control room side, the recordist may use a headset unit that

combines headphones with a small microphone before one's mouth,)

The Mackie Big Knob talkback unit allows you to 'talk back' to the people inside the

recording areas, as well as choose between multiple audio inputs.

Many mixer units include a talkback section built in, which may help

you avoid the need for a separate talkback setup.

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14. Optional 1: Patch-board or jackbox: If there are lots of different pieces

of equipment in the production studio, some recordists prefer to have a

patchboard installed. This is essentially a unit with lots of audio jack sockets

to which all the inputs and outputs of the equipment in the studio are

wired. Instead of keeping them all connected with a jungle of cables, the

recordist can now connect only the pieces of equipment he or she actually

wants to use, with short connector leads. It's a good way to keep away

from the nightmare of a tangle of cables, and from the need to plug and

unplug connectors if there are limited inputs and outputs on the mixer

or DAW.

For more on patchboards, see Section B: Patchbays on Page 121

15. Optional 2: Additional players and recorders: Since pre-recorded

programmes may draw on a variety of different audio sources for their content

- features and documentaries, especially, may tap into old archival recordings

- it may be wise to have a spool recorder, a turntable/LP player and other

player units as part of the production studio equipment. These, however,

are comparatively infrequently used, so you may decide to have a single set

that is shared between the broadcast and production studios - not a problem

at all if you have a single studio setup - or dispense with them altogether, and

arrange to rent or borrow them if required.

An 8 jack modular patch panel from Hosa.

More such modules can be added to this one to expand the

patch bay as the equipment increases.

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A brief note on the equipment suggested in this chapter

In this chapter, we have looked at ideal setups, and the types of

equipment that are typically required by a well-equipped CRS. These

suggestions must be adapted to your requirements: Feel free to mix and

match, get double duty from single units of equipment, and avoid certain

pieces of equipment wholesale.

Make the effort of finding out what other CR setups are using, as this will

give you ideas on how you can develop your own setup.

Above all, plan for the future and plan to add equipment bit by bit as

you go along: Starting with a very basic setup will still allow you to make

quality programmes. It's the mind and the ear behind the equipment

that make good programmes, not the equipment itself.

Don't get caught up in technolust and want a piece of equipment just

because another CRS has it, or because you have a fixed idea of what a

studio should be equipped with: Your decisions should be ruled by

logic, rationale, an eye on your budget and common sense.

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TECHNOLOGY - III

FIELD RECORDING EQUIPMENT

Chapter 4

Now that we've had a good look at the kind of equipment we need to equip

our studios with, it's time to examine what kind of field recording equipment

a community radio station needs.

Why do we need field recording equipment?

The simple answer to that is: Because we cannot gather all the audio we

need for a programme within the confines of a community radio station or

the studio. Sure, the studio may be connected to the outside world with

telephones and other communication equipment; but the fact remains that

some audio can only be recorded 'on location' or 'in the field', as it's called.

For instance, there may be people who cannot come to the studio to be

recorded, or to participate in a discussion, but who may be important to the

content of a programme. (A busy government officer, say, or a villager in a

remote area, who has no means to travel to the studio.)

A field recording in progress by volunteers at Mandaakini

Ki Awaaz Samudayik Radio in Uttarakhand.

There may also be audio which can only be recorded at the place where the

sound is actually produced: Natural sounds like birdsong, or the sound of a

waterfall, say; or the sounds made by a wedding procession.

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What are the main considerations in selecting field recording

equipment?

Since field recording equipment - unlike our carefully protected and shielded

studio equipment - is exposed to dust, humidity, and extremes of

temperature, it is important to consider the following factors while selecting

field recording equipment:

1. Ruggedness: Any equipment we move around with should be able to

take some basic knocks and bumps without malfunctioning: Climbing in

and out of vehicles, travelling in crowded buses, and hiking some distances

on foot are par for the course for CRS volunteers, and the equipment should

be able to take that. (Note that this does not include rough handling or

dropping the equipment - that's just plain carelessness, and there's no excuse

for that.) You'll find that modern solid state recorders, in particular, fulfill this

condition well, as they have very few moving parts.

The portable Marantz PMD 660 flash recorder. Designed

for field use, the recorder is able to handle large

variations in humidity and temeperature.

2. Resistance to humidity and dust: Many pieces of electronic equipment

are so sensitive that they cannot withstand shifts in temperature - interior to

exterior, for example, or from sunshine to shade. Others get easily fouled by

the fine dust that pervades Indian cities and rural areas, and need multiple

cleanings of their heads and other moving parts to stay in working order.

Such pieces of equipment cannot be part of our field recording kit. While

some maintenance is unavoidable, the ideal field equipment will not mind

a bit of dust, and have a large operating temperature range.

For more on maintenance and protection of equipment, see Chapter 7: Planning

for Maintenance & Management on Page 91

3. Adaptability and portability: While we are in the field, we do not have

the luxury of carrying large varieties of equipment to suit different situations.

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The recording equipment we carry has to give adequate or good results in

all the situations and recording conditions we are likely to encounter. (This

means the microphone has to be good for delicate as well as harsh sounds,

voices as well as music, able to work in noisy conditions and in quiet.)

Similarly, this will be equipment we will be carrying on our persons most of

the time, so it has to be reasonably light, or we will be weighed down and

tired out by just the effort of carrying it around.

4. Availability of spares and ancillaries: While most modern electronic

equipment is too complex for us to expect that there will be people capable

of repairing faults wherever we go, always plan on acquiring field recording

equipment for which supplies are available easily in the areas you work in.

For example, choose equipment that uses standard AA, AAA or D cells over

fancy proprietary batteries that may not be easily available: The standard

batteries are usually available somewhere close by no matter where you are.

Similarly, if the availability of recording media is an issue for you, it makes

better sense to choose an audio cassette based recording device than a

MiniDisc or DAT recorder. (Of course, this is not always a problem - MDs and

DATs, for example, are highly reusable media, and can be erased and reused

several times, thereby increasing the gap before fresh supplies are needed.)

For more on maintenance and protection of equipment, see Chapter 7: Planning

for Maintenance & Management on Page 91

What should a field recording kit consist of?

The components of a field recording kit are really very individual to the

setting of the CRS and the preferences of the field reporters; but there are

some broad components which we should include:

1. Microphones(s) & accessories: Ideally, the field recording kit should have a

couple of microphones, one with a wider pickup, that can be used to record a

group of people or a sound effect; and one that is highly directional and has a

narrow area of pickup, for noisy situations or to isolate particular sounds. But

this is usually a luxury, so it is more likely that you will have one multipurpose

rugged microphone that will give you acceptable results in most conditions.

A basic digital audio recording kit. Note the case within

which the recorder is carried to protect it from dust.

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The mic should have a good grip, to allow it to be comfortably handheld;

and should be accompanied by a foam or fiber windshield that prevents

wind from hitting it and causing a rumbling noise. Most field mics use

standard AA or AAA batteries. A balanced output is to be greatly preferred,

as that assists us to get clean recordings even in areas with high

electromagnetic disturbances.

Microphone cables matching the connectors, naturally, will also be part of

the kit - unless the microphone connects to the recorder wirelessly. Cables

should be of good quality and purchased readymade or made by someone

who knows how to do it, to avoid problems in the field.

It's usually a good idea to carry one or more spare microphone cables as

part of the kit, so that some spares are available if the main cable is

damaged for some reason. The spare cables could also be of different

lengths, to allow us to use the mic at varying distances from the recorder -

2 metre, 5 meter and 10 metre lengths should be fine. (But it is wise to

remember that not all mics give a good quality signal over cables longer

than 5 metres.)

For more on microphones, see Section B: Microphones on Page 198

2. Recorder unit: The field recorder should - besides being rugged and

hard wearing - be easy to use and set up. A unit with very complex pre-

recording processes will invariably cause you to miss important recordings

which you otherwise should have managed to catch. It should have balanced

inputs, for the reason stated above; but also allow you to connect a variety

of different types of mics to it: Standard inputs could include professional

(XLR and large ¼" phono) and semi-professional (RCA, mini 1/8" phono)

inputs, if possible.

For more on connectors, see Section B: Connectors (Audio & Telecom) on Page 166

A headphone socket, to allow us to monitor what we are recording, is vital,

as is the ease of changing used media for fresh media: There is nothing more

irritating than having to struggle to insert a fresh cassette or MD in the middle

of an interview. Ideally, you should not have to change the recording medium

at all during a field recording trip.

The recorder should also run off batteries; and have a low power draw,

allowing us to use fewer batteries in the field. To have easily replaceable

standard batteries is a distinct plus.

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The Zoom H2 Handy recorder. With a small form factor

and built in stereo mics, this recorder works on two AA

cells and records on SD flash memory.

A large and clear display screen, that lets you observe all the important

parameters - battery life, the amount of recording media left, the audio

level and the track number (if applicable) is a great plus.

A digital recorder, which allows us to sort and classify recordings as we go,

as well as save time during the transfer process to our editing systems, is also

a wise investment, especially if we have a DAW based editing process: It's

usually possible to transfer the recording into the computer very quickly

from a digital recorder. This is not possible if we use an analog recorder with

a DAW, where the transfer process will be as long as the time it takes to

physically play back each recording (i.e. 5 hours of recording = 5 hours of

transfer time.)

For more on field recorders, see Section B: Field Recorders on Page 184

For more on digital recorders, see Section B: Flash Recorders on Page 187

3. Recording media: In case the recorder needs replaceable media for

recording, there should be adequate supplies of blank media to cover all the

recording planned for the day. (Estimating how much media is required is

an acquired skill.) A good rule of thumb is to estimate the total recording

time anticipated, estimate the blank media accordingly, and then add enough

to cover a recording 1/3 rd longer than anticipated.

The cost of the media is a consideration, of course, with cheaper media

often being kinder to you operating budget. But do factor in the reusability of

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the media as well - an MD which costs a lot more, but can be reused fifty

times may actually prove more economical in the long run than a very low

cost medium like the audio cassette, which is cheaper, but can only be used

only a few times before the recording quality starts to drop.

Secure Digital (SD) and Compact Flash (CF) memory are

solid state and have no moving parts. Very small cards can

now give several hours of broadcast quality recording.

Don't be stingy while carrying spare media - better to have a few

unused cassettes and MDs at the end of the day than to travel miles

to find that you've run out of media and have to miss out on the best

interview of the day.

Modern flash based solid state recorders have much to commend them in

this respect - memory is rapidly becoming cheaper, and vast amounts of

recording can be made on one relatively inexpensive and reusable memory

card.

For more on flash recorders, see Section B: Flash Recorders on Page 187

4. Power supply: Most good field recorders come with an a/c mains power

adapter, but also run off batteries. The dual supply system allows you a

longer recording time in the field, as we can plug in wherever we have

access to mains power supplies. It's a good idea to carry at least one totally

fresh set of spare batteries for the recorder and for the mic (if it is powered).

It is ideal to carry appropriately sized Nickel Cadmium (NiCD), NiMH

(Nickel Metal Hydride) or LiIon (lithium Ion) rechargeable batteries that

are compatible with our equipment, along with charger units for each

variety, so that we can recharge batteries along the way where possible.

Many pieces of equipment come with internal rechargeable batteries in the

first place, that are charged by the accompanying a/c adaptors.

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A family of alkaline cells from Maplin. It is important to identify and

carry the correct batteries for your equipment when in the field.

As a rule, rechargeable batteries have a longer life than standard dry cells. If

rechargeables are not a part of your kit, try using lithium or alkaline cells

(Energizer, GP or Duracell) - these are long life dry cells, but can be quite

expensive on a recurring basis.

All rechargeable batteries have a finite life, measured by the number

of time they can undergo charges and recharges. (Each charge and

discharge is called a 'charging cycle', and a given battery may be

rated as good for a 1000 recharge cycles, or 20000 recharge cycles.)

NiCd and NiMH rechargeable batteries are especially prone to losing

their capacity to hold a charge after some time, a phenomenon called

the 'memory effect'.

5. Headphones: A good pair of headphones to monitor the recording is an

important part of the kit. Some recorder units come with a pair of high

quality in-ear earphones, but a pair of over-ear headphones with comfortable

padded earcups, and a long enough lead are to be preferred over this. Noise

canceling headphones, which allow you to cut out environment noise, are

also of great help, if you can afford them.

Yamaha's RHC headphones are low cost and affordable

while remaining hifi enough for professional use.

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A good pair of headphones, remember, can help you spot audio problems

while you are still in a position to do something about them - so get the best

pair you can afford.

For more on headphones see Section B: Loudspeakers & Studio Monitors

on Page 190

6. Carrying cases and covers: Field recording equipment should always be

carried in their carrying cases: There are a variety of cases, hard and soft,

available for each piece of equipment, with many cases designed to allow

operation of the equipment with the case still on. (This is especially true of

the soft rexine or plastic carry cases that go with many field recorders.) The

cases protect from jars and scratches, as well as dust; and most have straps

and belts that allow you to sling the equipment around your waist or over

your shoulder for easy carrying.

If standard cases are unavailable or too expensive, it's easy to stitch cloth

cases with straps for the various pieces of equipment. A stout kit bag or hard

case for the entire kit is also a good idea, both in terms of transporting the

equipment safely, and in terms of keeping the kit organized.

7. Optional 1: Cleaning kit: A cleaning kit containing cotton swabs, surgical

alcohol or cleaning fluid and an antistatic duster is a vital addition to your

field recording kit if you are using a cassette recorder in the field, as they

require frequent cleaning of the heads and pinch rollers. This is much less

important with latter day digital recorders, where there are no magnetic

heads that are exposed or even user accessible. A clean duster cloth is a

good idea anyway.

8. Optional 2: Boom rod/fishpole: Many microphones can be fitted onto a

long extensible rod called a boom rod, so that they can be held closer to a

subject or sound source from a position several feet away. (This can be an

important consideration while recording natural sounds in inaccessible

places, for example.) There are also flexible versions of this called fishpoles.

Depending on the kind of situations you record in, you might like to make

one a standard part of your kit, or have one available for use as needed:

They are especially useful in news situations, where a crowd of reporters

may be jostling to use their recorders simultaneously!

9. Optional 3: Accessories pouch: Some field reporters like to be prepared

for any eventuality and carry a simple repair kit - soldering iron, solder

wire, flux, miniature screw drivers, cutter and pliers - as well as marking

chalk, rubber bands, cable ties and spare connectors. This is a good idea,

especially if you make the effort to learn how to do these basic repairs on the

fly - it has saved more than one field recording trips from disaster!

For more on repairs and maintenance see Chapter 7: Planning for Maintenance

& Management on Page 91

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TECHNOLOGY - IV

TRANSMISSION EQUIPMENT

Chapter 5

The transmission process, as we have seen, is more or less the final step in

getting the audio from our studio - live and pre-recorded - out to listeners.

Let's pick up the process at the point the final audio signal leaves the broadcast

mixer, and see how it carries on from there:

Fig 5-1. Schematic diagram of the transmission and reception process

1. The Compressor/Limiter: The incoming signal from the broadcast studio

to the transmitter is (if we've done everything right so far) already somewhat

controlled and corrected from the audio level point of view. But this still

needs to be processed in order to keep it within a stricter range, so that the

transmitter isn't overloaded by a signal that it cannot handle. That's where

the compressor/limiter comes in: It controls the signal and keeps it within the

range the transmitter can handle, so that the broadcast radio signal is

distortion free, and so that the sensitive components of the transmitter are

not damaged.

For more on Compressor/Limiters, see Section B: Compressor/Limiters on Page 149

2. The Studio Transmitter link (STL): The studios and the CR station are

usually located in a place where people from the community can access the

station easily. But that's not necessarily the best place to put the antenna,

which has to be at a vantage point which overlooks the largest possible area

for broadcast. And since the transmitter is usually placed in close physical

proximity to the antenna, this means we have to find a way to get the audio

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signal from the station/studio to the transmitter. This connection is called the

studio transmitter link or STL. It can be a physical (wired) connection, using a

tough armoured cable that can withstand the vagaries of weather and direct

sunlight; or it can be an all weather microwave radio link that connects the two.

There are two key considerations where STLs are concerned: If it is a cabled

connection, then there is the matter of cable loss: The reduction in signal

strength due to the resistance offered by the cable itself. This can often be

quite sharp, and may play a large part in the deciding what strength your

transmitter has to be. The lower this loss, the better the cable - and the higher

its cost. But it is generally wise to keep the studio to transmitter and the

transmitter to antenna distance as short as possible: Many agencies advise

keeping the studio to transmitter distance under 50 metres.

Fig 5-2. Keeping the STL cable as short as possible is a vital consideration.

It is a good idea to install the antenna mast on the roof of the studio building itself

in order to keep the distance to a minimum, and gain the added height offered by

the building itself.

Wireless STLs, though not specifically banned under the guidelines governing

CR broadcasting in India, invite a whole different set of issues: The microwave

link will be treated by the Dept. of Telecommunications as a separate radio

link, requiring a license from the Wireless Planning and Coordination (WPC)

committee of the Dept. of Telecommunications. It will also involve a separate

spectrum fee, which can be quite high. This is, of course, in addition to the cost

of the link equipment itself, which is likely to add a few lakh rupees in the first

place.

3. The Transmitter: The transmitter is the central component in the

transmission process, and is a device that performs two functions: It generates

a radio frequency wave that carries the audio signal (and is hence called the

carrier wave); and it combines the audio signal that we input into it with the

radio wave it generates (a process called modulation). The combined signal

is very specific and precise, and is fed to the antenna.

Antenna

Mast

Transmitter

Studio

50 meters

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A NICOM USA 30W FM transmitter. Note the LCD screen on the front which reads out

the frequency setting of the transmitter.

The transmitter needs to be set up by an expert who can set it to a precise

frequency, and test whether it is working well. During testing, the transmitter

may be connected to a test or dummy load, instead of the antenna, to

simulate transmission.

The transmitter must never be run without either a dummy load or

the antenna connected to its output, as that can damage the unit.

Depending on the size and complexity of the unit, it may have a digital

display that shows the current frequency and the strength of the outgoing

signal. There is usually a built in system that allows you to set the frequency

of the carrier wave it generates to a specific value. (This is usually in steps of

1000 kHz, meaning we can set the unit to (say) 102.1, 102.2 or 102.3 MHz,

with the 0.1 MHz differences corresponding to the 100 kHz steps. Practically,

of course, stations are only allotted frequencies separated by at least 200

kHz on each side - that is, 92.0 MHz, 92.2. MHz, 92.4 MHz and so on-to

prevent accidental transmission overlaps ('interference') that could disturb

transmissions over the two neighbouring frequencies.)

Small and medium range stereo and mono FM transmitters are manufactured

by West Bengal Electronics Corporation (WEBEL), and Bharat Electronics

(BEL), as well as several foreign companies like Itel and Veronica. Several

other makes and varieties are available, including kits from organizations

like the California, USA, based Free Radio Berkeley. With a moderate

knowledge of electronics, one can build transmitters from pre-fabricated kits

and from the basic electronic components on the basis of circuit designs

available on the internet and elsewhere.

It is illegal to make or own an unlicensed transmitter under Indian

law. Indian regulations currently allow only transmitters meeting a

set of stringent international broadcast specifications. If your

transmitter is manufactured by a non-standard manufacturer - or you

have assembled it yourself! - you can only use it if it is officially

certified by a Bureau of Indian Standards recognized physical

laboratory that can test its adherence to these parameters. The

transmitter is expected to conform to the requisite International

Telecommunication Union - Radio Communication (ITU-R) standards.

For a list of NABL certified labs, go to: http://www.nabl-india.org/

nabl/asp/users/labCatBrowsing.asp

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Stereo or mono transmitter?

One of the important decisions to be taken by every CR station is whether

the transmission should be in mono, or in stereo. FM radio technology

inherently allows the transmission of CD quality stereo audio, so this is

a decision that needs some thought.

For more on mono and stereo audio, see Section B: Stereo & Mono on Page 217

In order to take an informed decision, we should consider the following

facts:

1. To get the full value out of stereo transmission, listeners require a

stereo receiver as well to listen to the programming.Most potential

listeners for an average CR station in this country are likely to be

using low cost transistor receivers - where the absence of a second

speaker makes stereo transmission pointless anyway.

2. Stereo transmission means mixing the audio in stereo to utilize its

full effect. Stereo mixing is a comparatively difficult skill to learn,

and needs considerable more practice than mixing in mono.

3. Stereo transmitters are more expensive than mono transmitters.

4. Stereo transmitters have a shorter transmission range than a

mono transmitter of the same power rating. (i.e. A 30W stereo

transmitter has a smaller range than a 30W mono transmitter.)

Of course, any decision we take on this matter also has to take into

account future developments in our transmission area -

technological developments like plentiful availability of cheap stereo

receivers, for example, or FM enabled cell phones. So be careful

and think ahead!

4. The Antenna: The antenna is a device made of metal, which radiates or

sends out the modulated radio signal into the air all around it. Antennas, like

microphones, can be directional (with much of the radiated energy sent in

one primary direction); or, more usually, omni directional, with the energy

being radiated evenly in all directions.

Siting or deciding the location of the antenna for best reception is an

important consideration, with high vantage points overlooking the maximum

possible area greatly preferred. This is why the antenna is usually fixed to a

tall mast or tower that is carefully anchored to prevent it from falling over -

the height gives it a greater vantage point.

For more on regulations regarding transmission power and antenna tower

height, see Chapter 9: CR Guidelines in India & their Implications on Page 105

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A simple homemade dipole

antenna. This unit is mounted

on a large bore metal post.

Fig 5-3. A basic self supporting tower design.

The antenna tower or mast can be of many varieties: The more complex

ones are self supporting tower designs on three or four stilt legs, with

built in ladders which can be used to access the antenna mounted at

the top.

Self Supporting Tower

Antenna

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The simpler ones, which cost much less, are the antenna masts. Such masts

are usually supported against wind by anchoring wires or guy ropes, in

which case they are often referred to as guyed masts. (Of course, in a pinch,

even a long bamboo pole that is suitably braced upright on a building's roof

could provide a more than adequate height for the antenna - especially in a

plains area.)

A guyed antenna mast, on the other hand, is quite easy to manufacture: All

it requires is a good fabricator (iron worker) who has basic welding tools.

You will require:

1. Angle iron (22 x 22 x 5 grade is quite adequate) in 10 or 15 foot sections;

2. Cross strut metal sections to provide the bracing between the three angles;

3. Nuts and bolts to attach the sections to each other, along with fish plate

style punched metal sections.

The sections are manufactured by connecting the three metal angles in a

triangular pattern, with equal sized cross-struts welded to the inner side of the

angles. If constructed in 10 or 15 foot sections, these can be handled easily,

and attached to each other with nuts and bolts holding the sections together.

Fig 5-4. A simple guyed antenna mast design. The inset shows how the 3 angles

used are interlinked and braced.

Care should be taken that there are no large physical obstacles -

mountains, hills or tall buildings - near the antenna that may block

the radio signal emanating from it.

Grounding of the antenna is a very important consideration, as a tall metal

tower is an open invitation to lightning strikes. The grounding of the antenna

is distinct from the grounding we have already seen for the station electricals:

This grounding is built to divert the millions of volts of energy from lightning

into the ground, to protect the transmitter and other equipment in the studio

Iron Angles

Dipole Antenna

Guy Wires

Iron Angle

Metal Cross

Strut

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from being jolted. If the electric charge gets back to them through the cables

and link, they will all be destroyed and lakhs of rupees worth of equipment

could be ruined.

Fig 5-5. Grounding the antenna mast is vital, especially

in hilly areas and storm prone areas.

The modulated radio wave emanating from the antenna can be received by

radio sets at all the locations within a finite range of the antenna. The strength

of the radio signal drops off with distance: Typically, for a 30 watt transmitter

(which should give 100 Watt ERP with a correctly matched antenna), this is

about 10 - 12 kms in the plains and 4 - 8 kms in the hills. The range refers to

a distance of adequate reception: Any radio set within that range will pick up

a strong signal that can be heard without the audio fading in and out, or with

breaks in the signal.

Mast

Antenna

Ground Level

Copper Plate

Salt & Charcoal Bed

Lightning Conductors

Grounding Cable

A note on the regulation of FM transmission

In the modern world, we are surrounding by a plethora of radio signals

used for telecommunications and data transfer, not to mention multiple

radio and television broadcasts running simultaneously. It would lead

to total chaos if anyone could broadcast any signal at any time: Think of

ten stations in a given area all broadcasting at the same frequency! This

is why there is a process of registration and allotment of frequencies.

The transmission process in India is stringently regulated by official

processes and government bodies.

Non-standard transmission equipment can also lead to spillovers of the

signal into areas beyond the allotted frequency, and that that can also

cause reception issues at the listener's end.

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A live CR broadcast in progress. There is no way to rectify

mistakes in production before a live programme is transmitted - so

such programmes call for concentration, coordination and skill from

the presenters and the producer.

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TELECOMMUNICATIONS

& ANCILLARY EQUIPMENT

Chapter 6

While setting up and running a CR station, it is also important to plan the

ways in which the station will connect to the world outside. Technology can

play a major role in the way the community interacts and participates in the

day-to-day functioning of the CRS.

Besides the transmitter and the broadcasting equipment itself, there are three

primary technologies through which the CR station can be connected to the

community and the world:

1. Telephones;

2. Facsimile or fax;

3. The internet (and email)

Section A: Telecommunications & telephony

1. Telephones

There are several types of telephone connections available nowadays:

(Wired) Landline, cellular (mobile) and WLL phones. In some areas we

may have access to all the three varieties, and in others to only one of the

three. Some sections of the country still remain unconnected even today

- but we can be hopeful that this will be remedied before long given the

rate at which the telecom networks are expanding.

a. Wired landline telephones: The oldest kind of telephone connection,

the wired landline connection involves the physical laying of a

copper wire telephone cable to the place where the connection is

installed. All the lines from all the phones in a given area are

connected to local telephone pillars or boxes; and thereby, to a

telephone exchange, through which they are connected to each

other, and to phones in distant areas.

The biggest drawback of landline phones is the wire (or 'telephone

pair') that actually covers the distance between the closest exchange or

pillar, and the place where the telephone instrument is installed: Being

a physical connection, it is subject to vagaries of weather; and also

often gets snapped by strong winds, passing vehicles or even animals.

In a remote area, a broken connection can take a long time to repair or

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A modern landline phone instrument. The landline phone is

increasingly losing out to the anywhere-anytime

convenience of cellular telephony.

replace, which means the station's connectivity is compromised in the

meantime. It is relatively easy for fixed line connection - especially in

tropical weather conditions - to develop a disturbing crackle or noise

that can make voices sound unclear.

b. Wireless in Local Loop (WLL) phones: A modern variation of the fixed

line phone connection, WLL phones get over the problem of damaged

pairs by using radio technology to connect the instrument to receiver/

transmitter units mounted on masts or towers in each area. The WLL

instrument is usually characterized by a small antenna that projects out

of the back of the instrument; and most units need a power source of

some kind (usually a battery, or mains power through an electrical

adaptor.) WLL phones can also be moved within a building as required,

unlike fixed line phones where the entire wire may have to be uprooted

and re-laid. Most phone companies also allow WLL instruments to operate

within a limited range of the installed premises.

A WLL phone instrument. The antenna on the right

side of the instrument links the phone to the

closest transmitter/receiver unit.

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c. Cellular Telephones: Like WLL phones, cellular phones use radio

technology to connect the instrument to a transmitter/receiver mounted

on a mast or tower close by. But unlike WLL phones, cellular phones

are mobile - a factor also governed by the extremely small size of the

instruments - with the signal reaching you wherever you are.

A Personal Digital Assistant (PDA) cellular phone

instrument from HTC. Increasingly, internet enabled

cellphones like this one are becoming all-in-one

communication and entertainment devices.

Types of wireless telephone networks

WLL and cellular networks usually work on one of two popular

standards: GSM (Global Standard for Mobile communications, more

common among cellular networks) and CDMA (Code Division Multiple

Access, available for both WLL and cellular networks).

GSM networks are more widespread globally, being an older technology.

But CDMA networks offer higher rates of data transfer, as well as

greater potential connectivity to internet and audio/video/multimedia

services. Both types of networks are constantly being upgraded and

new research being done to improve service quality - so both now offer

a variety of value added services and higher speed connectivity,

collectively now known as 3G (third generation) services.

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2. Facsimile (Fax)

The facsimile or fax machine is a device that allows you to scan documents

and send them to a similar device over a standard telephone line, where the

document can be printed out. Even though they are increasingly becoming

obsolete in a world where the internet and email prevail (see below) they are

still useful devices - a variety of organizations are still not totally computerized,

and rely on fax machines for document transfers.

Fax machines need electricity to run; and also need a clear line for

transmission or reception. If the line is damaged or unclear in any fashion,

the received image tends to be distorted or incomplete.

A fax unit from HP. Though email is now rapidly replacing the fax

machine, the device is still favoured by many government offices

and by smaller organizations in the field.

Fax machines are of many varieties, notably those which store numbers in

a memory, and those with timers that can automatically send pre-scheduled

faxes at a specified time. Another important consideration is whether the fax

machine uses thermal paper (more common) or regular paper (less common,

also more expensive.)

Thermal paper holds images only for a few days before the image

starts fading. If you use a thermal paper fax, photocopy the fax as

soon as possible.

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Which type of phone and how many lines?

Which type of phone you select for your CR station is governed by what

is available in your area most conveniently; and by how you want to

equip the office, studio and staff.

Where phones for the office are concerned, you may want a line each

for each of the following:

1. The office line: This connection will be for administration, research

and other functions. If you have a large setup, with a number of rooms,

this line may be connected to an EPABX, a device that allows you to

connect multiple instruments to the same telephone line or lines. (The

multiple instruments can then also connect to each other - forming an

intercom system - with the outside line accessible from any of the

instruments.)

2. The studio line: This line is for callers to call the studio for phone-in

programmes and to participate in programme activities. The line is

connected to a telephone hybrid unit, a device that lets you relay the

sound coming over the telephone line into the mixer unit, and use it as

an audio source. The caller's voice can then be incorporated into the

programme, and - if the line is connected to the production studio -

recorded for later editing. Phone hybrids can thus be used for:

zConducting interviews with people who cannot be accessed directly

for a recording

zCalls in by listeners who would like to request songs or programmes,

or respond to questions

z'Live' broadcasts by reporters in the field (including events)

3. Feedback and listener response: To let listeners call in with their

opinions regarding the programmes the station is broadcasting, you

might also consider having a separate line connected to an answering

machine, a device to record incoming calls. Answering machines are

available as standalone units which automatically record incoming calls

on cassettes or (more lately) solid state memories. Software is also

available to let you connect a phone line to a computer, in which case

the computer records the calls directly onto its hard disk.

4. Fax line: If use is likely to be heavy, it makes sense to have a dedicated

line for the fax machine. On the other hand, if you will be using the fax

only sporadically, it could share the main office line, with the fax machine

switched on or off as required. Contd...

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Fig 6-1. A typical distribution of telephone lines in a middle level CR station.

Smaller CR stations often get multiple duty out of a single incoming line.

It's really up to you to choose which type of connection is best for

your situation. It is a wise idea to not have WLL phones or cell

phones for the studio line, as having a wireless unit close to audio

equipment can mean disturbances in the audio that is being

broadcast or recorded. (This is why all studio staff are generally

advised to switch their cellular phones off when in the studio.) WLL

phones are also usually not connectible to fax machines, so this

should be a consideration when investing in a WLL phone for the

office.

Any phone units or extensions installed in the studios should also

have the facility to mute the unit - keep it from ringing - so that it

doesn't actually sound when audio is being recorded or broadcast

from the studio. Many specialized phone instruments are available

for this purpose, with blinking lights indicating incoming calls

instead of the standard ringtone.

If your radio station is constantly receiving more calls that one phone

line can accommodate, it is a good idea to invest in more phone

lines for the studio - there is nothing more frustrating for a listener

than to be invited to call in and get an engaged tone. More than one

line, while not a perfect solution, increases the chances that a caller

will get through. Combined with a hunting phone system, which

searches for the free line out of the ones connected to it, this can

provide a much better connectivity experience for your listeners.

(Multiple lines may also need multi-line telephone hybrids to connect

to the mixer system, and this can be very expensive!)

For more on telephone hybrid units, see Section B: Telephone Hybrids on Page 220

OFFICE

LINE 1 EPABX

FAX

INSTRUMENT 1

TELEPHONE

HYBRID MIXER TRANSMITTER

LINE 2

LINE 3

LINE 4

STUDIO

INSTRUMENT 2

INSTRUMENT 3

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Finally, you may like to consider the value added services available

with a given choice of telephone line - WLL connections and cellular

connections also offer you the ability to see incoming callers' numbers

(caller ID) and send SMSs (Short Messaging Service, short text messages

that can be transmitted to another phone working on the WLL or cellular

system.) SMS, in particular, is increasingly being used by stations to ask

listeners to make requests, vote for songs and/or send in their opinions.

When calculating approximate costs of operation, remember

that fixed line and WLL phone connections generally charge a

flat per month rental, along with a usage charge that is linked to

the number of calls made. Cellular phone connections are either

postpaid (with a rental and call charge structure like the one

described above) or prepaid (where a predetermined amount

is deposited in advance in exchange for a fixed amount of

calling time.)

3. Internet & email

Most modern offices are connected to the internet, a worldwide network of

computers and data relay systems that allows access to information stored on

the network. The internet is a huge resource, with billions of websites - collections

of electronic web pages - providing a variety of information on organizations,

people, and events (and increasingly audio and video clips as well.)

Its ability to transcend geographical boundaries allows the creation of global

electronic groups which can hold discussions on issues and information of

common interest. It also allows individuals and organizations the ability to

publicize themselves, their work and their ideas at relatively low cost. Most

importantly, its value as a repository of information transcends traditional

encyclopaediae, making it a hugely important component in research.

Connecting to the internet requires computers equipped with browser

software, specialized software that can interpret data available on the internet

in electronic language designed for fast and efficient data transfer over the

world wide web, as it often called.

Most modern computer systems come pre-equipped with browser

software: Internet Explorer is usually included as part of the Windows

operating system, with free software like Mozilla Firefox, and Opera

also widely available.

Websites follow a naming convention that uses http:// or www followed by

a name and a .com/.org/.net suffix that identifies them uniquely. This must

be entered in the browser window to access the page or site.

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But perhaps the single greatest use of the internet is the ability it gives us to

send electronic mail or email - electronic messages that travel over the

internet almost instantaneously. Email communication is rapidly becoming

the modern communication standard, especially since it now allows us to

attach electronic computer files to mail messages. Many websites provide

free email services, where you register to get a unique email address

(xyz@mymail.com, for example) where others can send email to you. Many

organizations tend to set up their own websites and their own coordinated

email addresses that include the organization's name.

Internet connections are usually provided by an Internet Service Provider

(ISP), who sells you a predetermined amount of connection time or data

transfer against a set fee. As charges drop, many ISPs now provide an

unlimited data and time connection against a per month flat fee. The ISP

runs a computer called an internet server that can be connected to your

computer in a number of ways:

a. Through a regular phone connection: Several ISPs are also telephone

service providers and offer combination packages that combine internet access

with phone calling. The fixed line phone cable, WLL instrument or cellular

phone is connected to the computer, which then sends and receives data

over the telephone connection. Many such ISPs offer a facility where the

telephone continues to remain active even while the internet connection is

on, though this is more common with DSL and ADSL connections (see below).

Fig 6-2. The computers in a CR station can connect to the internet in a variety of ways.

Wireless Wi-Fi connections are rapidly becoming popular in offices.

b. Through a dedicated internet connection: Many ISPs also provide

connections that are meant specifically for high speed internet data transfer.

These could include internet over LAN, where the connection is provided

over the type of cable that is used to connect Large Area computer networks

(LANs); ISDN (Integrated Services Digital Network), a high quality copper

wire telephone line usually provided for internet connections by telecom

LAN Cable

Telephone Line

Wireless

Router

Wireless

LAN Card

Modem

LAN

Card

Modem

ISP

Internet

Server

CR Station

Computer

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service providers; and DSL (Digital Subscriber Line) or ADSL (Asymmetric Digital

Subscriber Line), which also uses a physical copper wire connection, but offers

very high data transfer rates. ISPs providing DSL or ADSL line often bundle

packages that include phone instruments and phone calling, as the DSL/ADSL

line is capable of easily handling both phone and internet traffic simultaneously.

Depending on what type of internet connection is being used, the computer

either needs a device called a modem (short for modulator-demodulator), which

converts the computer's digital data into analog audio signals which are then

transmitted over the network to the internet server; or a network or LAN card, a

piece of equipment that allows computers to connect to each other. Discuss this

with your ISP before acquiring an internet connection: They will let you know

what the specifications and equipment you require will be.

More internet based communication opportunities

As the internet plays an increasingly larger role in our lives, it is also

leading radio stations to leverage new technologies. Most popular among

these technologies are:

1. Blogs or web-logs: These are online internet diaries maintained by

individuals or members of a team or organizations, which offer an

opportunity to share personal observations, experiences and memories.

Many websites and ISPs offer visitors or users space on their internet

servers to host blogs, which can then be accessed by anyone visiting a

specific website. The newest variant of the blog is the audio blog or

video blog, which offer the author of the blog facilities to present audio

and video recordings respectively as part of the 'diary'. Almost any

audio recording once converted to digital form can be used for this

purpose. Popular blog sites include www.blogger.com,

www.blogspot.com and www.wordpress.com.

2. Podcasts: Named after the popular Apple iPod music player, a podcast

is an audio programme hosted on a website, which can be downloaded

to one's computer or digital music player and heard by the listener.

Though a good internet connection is called for - podcast files can be

large in size for longer programmes - the advantage over broadcasting

programmes is huge, as it allows one to listen to the programme at

leisure. Many long-running prodcast series are now available over the

internet, and many international media organizations like the BBC now

regularly make their programming available as podcasts. Try http://

news.bbc.co.uk/2/hi/programmes/documentary_archive/ to hear some

interesting podcast radio documentaries.

3. Streaming audio and internet radio: With comparatively inexpensive

software and a good internet connection, it is now possible to schedule

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and play programmes over the internet to listeners who connect to your

website or server. The audio - although in lower quality than broadcast

level audio - can even be customized according to the listener's

preferences, in terms of selecting which programmes to hear, or the

order in which the programmes are played back. At the receivers' end,

all that is required is a computer with some commonly available

streaming multimedia players like Windows Media Player or Real Audio

player; a good internet connection and a pair of speakers or headphones

over which the audio can be heard. A large number of internet radio

stations are now active, and may be accessed over the internet.

For CR stations, podcasts and internet radio present an additional

opportunity to air programmes and expand their listenership beyond

the local audience, as well as listen to other programmes from groups

working in other geographical areas. Since both these technologies are

license-free (or unregulated) and give the listener the ability to control

their media consumption, they are seen as important changes in the

traditional scheduled broadcast model in a globalizing world that now

works across political boundaries and time zones.

Section B: Other office equipment

As we have seen in the previous section, the office requires a variety of

telecommunications equipment for its functioning. In addition to all this -

and as indicated by what we have already discussed - we must consider the

following equipment for the office:

1. Computers (for administration & research): In today's world, computers

are not only at the heart of broadcast systems, they are an ubiquitous part of

the office as well. You should consider a at least one computer for the office -

more than one, if you can find the funds for them! - as everything from

documents to records to financial matters are now maintained on computers.

A modern branded desktop computer system from Lenovo.

While branded desktops often carry extended warranties,

assembled PCs often let you match components of your choice.

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Office computers need to be of far simpler specifications than the DAWs we

saw in a previous chapter, as they type of data they are expected to handle

is primarily text and numeric. But they do need to be equipped with

accessories that allow them to connect to the internet (modems) and/or to

other computers (network or LAN cards). Of course, if you intend to use

them for more demanding applications - like transferring audio programmes

over the internet, or playing back audio or multimedia from internet sources

- then the specifications will need to be higher. But a computer like this

should usually be more than enough:

A basic configuration for an office computer

zIntel Pentium-4 3 GHz or Intel Core 2 Duo Processor 1.83 or higher

(or) AMD Athlon 3000 dual core processor

z120 GB hard disk drive (160 GB preferred)

z512 MB RAM (1 GB preferred)

z15" LCD or CRT monitor

z56K modem

z10/100 Ethernet (LAN) card or Wireless network card (if you have a

wireless router)

zATX cabinet with 300W SMPS power supply

zAppropriate motherboard for processor above (integrated audio and

video are fine)

zAt least 4 USB ports+serial port+Firewire port preferred

zStandard 101 keyboard and 3 button mouse

z750 VA Uninterruptible Power Source (UPS)

You can buy pre-designed branded computers, or have one assembled to

your specifications from components by an assembler. Discuss computers

with your local computer supplier or with someone knowledgeable regarding

computers and networks so that you can get a system appropriate for your

needs.

For more on computer hardware and software, see Section B: Computer

Hardware on Page 152 and Computer Software (for Radio) on Page 159

2. Network hubs/Routers: If you have multiple computers in the office, it is

usually advisable to connect them together so that they can transfer files and

data between them. The connection is usually achieved with a network hub

or router switch. If each of the computers is equipped with a network card,

and the network cards connected to the hub, the computers will be able to

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share data. Some router equipment allows you to connect the internet

connection to the router itself, so that it can be shared by all the office

computers - though it must be remembered that the more the number of

computers sharing the internet connection, the slower the data transfer speed

that each experiences will be.

A Linksys WiFi (802.11g) wireless router.

Such a router allows WiFi enabled laptops and desktops to

connect remotely to it within a given range.

Nowadays, routers and network hubs are also available in wireless versions,

based around the 802.11 standard. This standard, known popularly as

WiFi, allows computers equipped with the appropriate wireless network

cards to connect to the router without cables. However, in a radio station,

using wireless equipment of this sort could conceivably interfere with the

audio studio's operations, so such equipment must be used with some care.

3. UPS: Every computer that you have in the office requires its own

Uninterruptible Power Supply (UPS), a battery based unit that doubles as a

device to correct variations in incoming AC mains voltages, as well as provide

emergency power during a power failure. Depending on its capacity and

the number and type of batteries attached to it, the UPS may provide enough

time to shut down the system, or run it during an extended power cut.

UPS batteries need to be replaced at regular intervals, as batteries

have finite ability to retain a charge - in regular use, this should be

about every two or three years.

For more on UPS systems, see Section B: Uninterrupted Power Supply

on Page 224

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A note on the equipment mentioned in this chapter

It is important also to remember that though computerized offices are to

be preferred, there is absolutely no reason why a CR station office cannot

work with much more basic equipment - typewriters and manual records.

A number of CR stations worldwide continue to operate effectively in

this fashion, and do a very good job of it.

Remember that equipment is not the be all and end all of a CR station -

and certainly not for the station office, even if it is important for the

studio and production work. What is important is getting the work done

and the broadcast running steadily - and within the limitations of the

budget that you have.

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An internet browsing programme being broadcast live by a CR

station . The programme is interactive: Listeners call in with

queries, which are then answered over the air by the show’s

hosts. The hosts find the answers to the queries on the internet.

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PLANNING FOR MAINTENANCE

& MANAGEMENT

Chapter 7

Since most CR stations run on stringent budgets and aim at serving the

community with a not-for-profit motive, it becomes very important that its

plans for the upkeep and maintenance of its equipment are up to the mark.

If done regularly and well, maintenance should:

1. Prevent breakdowns before they happen;

2. Avoid unnecessary operational hassles and expenditure;

3. Ensure that the broadcast and production process is never interrupted,

and that a good quality transmission goes out all the time.

Setting rules and regulations in the studio

Maintenance starts before the breakdown happens! So start by creating

some simple rules for studio access and use - and enforce them strictly.

These include:

1. Cleanliness: Dust and dirt should not be allowed into the studio areas - that

means no shoes or dirty clothes, or even food or drink in the studio areas. No

pets should be allowed into the studio area either - animal hair is just as bad as

dust! Ensure that the studio area is swept and mopped every day.

2. Trained personnel only: Put in place systems that allow for consistent

capacity building of volunteers and producers on how to handle the

equipment, and - as far as possible - allow only them to actually work in the

studios. All too often damage occurs because someone is just fiddling with

the equipment without really knowing how to use it. Of course, fiddling with

equipment is part of learning how to use it as well - so the trick is working out

a balance. (Strategic signs placed all around the office and within the studio

may play a useful role in inspiring people to fiddle responsibly!)

3. Report problems as they happen: Instruct staff and volunteers and staff to

report any problem, however small, as soon as they experience it. This will

avoid the problem snowballing into a much greater issue. Computerized

equipment, in particular, often signal when things are going wrong with a

number of error messages. Instruct staff to note error messages whenever

they appear so that the problem can be diagnosed.

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Members of a CR group learn how to repair their field

cassette player units. Field units need servicing on a

regular basis to keep them in peak operating condition.

Never force equipment to work - if a CD tray is stuck in the eject

position and doesn't go back in, don't manhandle it into going back

in! Your haste may damage an expensive piece of equipment and

make it unusable!

Planning for maintenance

It is a good idea to incorporate a regular inspection process for all equipment

into the management process - that way, equipment testing is done on a

regular basis and possible trouble spotted early. Also, since radio and

broadcast equipment is costly to repair - and given that repair facilities may

not always be easy to access in your area - planning in advance for possible

repairs allows you to manage the expenses in a way that is more convenient

to you.

Planning includes:

1. Scheduling a system of equipment checks, and designating the people to

carry them out;

2. Maintaining a log of equipment trouble faced and repairs carried out;

3. Maintaining a filing and documentation system where original equipment

warranties and manuals are stored for reference;

4. Keeping a database of repair facilities and tech support persons accessible

for ready reference;

5. Incorporating a maintenance budget into the yearly or monthly operational

budget for the station;

6. Scheduling a regular training process that teaches station staff how to

work on the equipment.

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Maintaining the documentation and plans

It is very important to maintain an orderly system to file and keep accessible

all the plans for the station - layouts, wiring diagrams and equipment manuals.

If these are kept handy, then a number of problems can be sorted out very

quickly when they arise.

Besides the fact that reading the equipment manuals allows the staff to learn

the functions and correct operation of the equipment, manuals often have

detailed instructions on procedures to be followed if the equipment gives

trouble. Consult them first in case you are finding issues with any equipment

- sometimes it can be as easy as switching the equipment off and then

turning it back on!

Maintaining records and documentation for equipment -

especially field equipment, which is often away from the

station - is vital to keeping the technology in good order.

The wiring layout of the station - electricals and audio cables - will help you

understand where a possible break or interruption may be happening. If

you don't keep this filed away and accessible, as people change and time

passes, the original layout will be forgotten and then you may have to

painstakingly rip the floor and walls up to rediscover where the cables go.

Update these diagrams and plans as you make alterations, corrections or

upgrades - that way you always have a current picture of the setup.

Warranties, especially, are very important documents - within the warranty

period, most equipment manufacturers will not charge labour or parts costs

to fix equipment. File these away carefully, and see that they are duly

completed when you acquire the equipment.

Warranties are not always available if you acquire equipment from

the unofficial market (often called the 'grey' market). So if you buy a

really expensive piece of equipment in the grey market, you may

save some money up front by buying it without a bill or at a discount

from an unauthorized dealer - but be aware that equipment failure

could cost you much more in repairs.

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It is also a good idea to evolve and file your own training manuals and

documents so that they can be accessed easily by staff - often manuals may

give too many details regarding the equipment, and a simplified version

may be useful to have for staff to use or train new volunteers with.

Maintaining inventories of equipment

It is also good practice to maintain an inventory or equipment list for all the

equipment in the station, and to affix labels that correspond to the entry in

the list to each piece of equipment. That way, it will be easy to find the details

of any individual piece of equipment almost instantaneously by just referring

to the appropriate entry in the list. The inventory should carry details like:

1. Name and model of the equipment

2. Serial number or unique ID

3. Function

4. Date of manufacture

5. Date of purchase

6. Name and contact address of the dealer

7. Warranty period

8. Situation (where is it located/installed)

9. Comments (a column where you can record remarks regarding the

equipment, including complaints and repairs)

Many of these details will have to be gathered from the papers that accompany

the equipment when it is acquired: Bills of sale, warranties, and so on.

Some of the details - serial number, model and so on - may be read off the

labels or printing that is usually affixed to the rear side of the equipment.

Serial numbers, in particular, are very important during repairs, as

this will be how you identify the equipment that has gone back to the

repair shops: The repair shop may have many similar units with it at

a given time. The serial number is also mentioned on the warranty, as

it identifies the unit uniquely.

The serial number of the equipment is usually mentioned on a label

on the side, back or underside of the equipment. Note that the

label also gives information regarding power ratings.

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Assessing (and investing in) maintenance skills building

It is also a good idea to see whether what the maintenance skills of various

staff and community members is - there may be people among them who

are adept at electric and electronic repair work, or who may even have

experience in repairing some of the equipment. Maintain a list or resource

directory of the people you identify.

Be careful while doing such an assessment - everyone enjoys being a source

of information, and a lot of people like being tech gurus, but may actually

not have much skill at all. If someone who only pretends to have experience

sets about doing a repair job, you may end up with more problems that you

started out with!

It is good to have some basic ability to repair equipment and clean and

maintain it - and that includes the ability to make running repairs that keep

the equipment functioning while more formal repair assistance can be called

for - but too much experimentation can be detrimental to the equipment:

Some parts can simply not be jury rigged, and being able to recognize

where something can be done and where one should not take the risk is a

very important ability.

It may also be a good idea to send staff out to equipment manufacturers'

facilities and maintenance centers to learn some basic repair skills for the

various kinds of equipment. Many manufacturers hold workshops and

preventive maintenance courses for their equipment, which you may be

able to access.

Assessing maintenance costs

When you run a CR station, the costs involved in repair and maintenance

often run beyond the simple costs of repair and spare parts: Many CR stations

are situated far away from the repair centers which can fix their equipment.

Repair and maintenance costs may therefore have to include:

1. Spare parts: This includes the cost of any replacement parts that may be

required to fix the equipment. Within the warranty period, this is generally

not a concern, but outside warranty, it is definitely a cost. Note that warranties

generally do not cover physical breakage, only normal wear-and-tear related

breakdown.

2. Labour: The charges related to the time spent by the technician in fixing

the equipment. Some suppliers will charge this as a flat fee as they already

have an assessment of the average time it takes to fix common problems.

These are also often covered by the warranty during the warranty period.

3. Travel & boarding: If the repair center is far away, you may also have to

pay the repair technician's travel to and from your station, as well as the

costs involved in putting him up if repairs take more than one day or travel

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exigencies require him or her to stay overnight. This can add up to quite a

lot, especially if the service center has rules regarding the kind of travel

facilities that they require. Additionally, the service person may not be carrying

all the spare parts required for a given repair job, as it is often impossible to

prepared for every eventuality - and this may require more than one trip as

a result.

You can save yourself some bother by noting error messages carefully

and reporting the problem faithfully and in detail when requesting

repairs: This may help the technician identify the possible problems

and come prepared with the appropriate tools and parts.

Even within the warranty period, travel and boarding for on-site repairs are

unlikely to be covered by the service center unless expressly mentioned in

the bill of sale or warranty. You may be able to convince the supplier to

include this as a facility when you acquire the equipment, so try and bargain

for it!

4. Courier & postage: Sometimes you may have to package and ship

equipment to the manufacturer or supplier in order to get it fixed. This will

require special packing, and shipping by courier, so that the equipment

arrives safely and without further damage at its destination. A good courier

company may charge you steeply for this service, especially since many

pieces of equipment are heavy, and shipping is charged on a weight basis or

a volume basis.

A CR volunteer discusses repair instructions over the

phone as he checks an electrical point. Doing some

basic preparatory work before calling in a technician

can save time and money.

Annual Maintenance Contracts

Beyond the warranty period, many suppliers and repair centers offer Annual

Maintenance Contracts or AMCs for the upkeep of the equipment. This

usually involves a flat fee per annum for the equipment covered, which

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takes into account all the costs mentioned above. Under the AMC, the

repair center usually does not charge you for every repair that they execute,

as they will be paid the fee whether problems crop up or not: It is their

responsibility to fix the problem, whatever it is, once the AMC is drawn up

and agreed upon.

AMCs can often be negotiated, and it is up to you to work out the best deal

for your station - try and get one or two preventive maintenance visits in a

year included within the terms, and check for loopholes that force you to

pay for specific portions of the repair and maintenance despite paying the

annual fee.

A good AMC contract should cover all the possible costs involved in keeping

the equipment running in good order, and also include a timeframe within

which problems will be fixed.

Many repair centers stop taking an active interest in your equipment

once they have been paid the AMC fee - after which they put your

work on hold while they attend to other paying customers. A punitive

clause that forces time bound responses from the service provider is

a good way to keep things in order!

General maintenance tips - A ready reckoner

1. Read the Instruction manuals - All the safety and operating

instructions should be read before equipment is operated.

2. Keep the Instruction manuals - The safety and operating instructions

must be kept for future reference.

3. Heed Warnings - All warnings on equipment and in the operating

instructions should be obeyed.

4. Follow Instructions - All operating and use instructions should be

followed.

5. Cleaning - Unplug equipment from the wall power outlet before

cleaning. Do not use liquid cleaners or aerosol cleaners. Use a soft,

damp cloth for cleaning the exterior of equipment.

6. Attachments - Do not use attachments not recommended by the

equipment manufacturer, as they may be hazardous.

7. Water and Moisture - Do not use equipment near water - for

example, near a bath tub, wash bowl, kitchen sink, or laundry tub;

in a wet basement; or near a pool or any similar wet or damp place.

8. Stability - Do not place equipment on an unstable surface. The

equipment may fall, causing serious injury to yourself or others,

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and serious damage to the equipment. Preferably all broadcast

equipment should be mounted in a rack or stand, recommended

by the supplier or sold with the equipment.

9. Equipment should be moved and carried with care. Rough

handling, quick stops, excessive force, and moving over uneven

surfaces may cause the equipment to be dropped or damaged.

10. Ventilation - Slots and openings in equipment cabinets are provided

for ventilation and to ensure reliable operation of the equipment

and to protect it from overheating. These openings must not be

blocked or covered when the equipment is in operation, though

you may be tempted to cover the equipment with a cloth or plastic

sheet to protect it from dust. The openings should never be blocked

by placing the equipment on a bed, sofa, rug or other soft surface.

Equipment should not be placed in a built-in installation, such as a

bookcase or rack, unless proper ventilation is provided or the

manufacturer's instructions have been obeyed.

11. Power Sources - This product should be operated only from the

type of power source indicated on the marking label. If you are not

sure of the type of power supply you need for the equipment, consult

the supplier or local power company. For products intended to

operate from battery power or other sources, refer to the operating

instructions.

12. Power-Cord Protection - Power-supply cords should be routed so

that they are not likely to be walked on or pinched by items placed

upon or against them, paying particular attention to cords at plugs,

convenience receptacles and the point where they exit from the

equipment.

13. Outdoor Antenna Grounding - If an outside antenna or cable system

is connected to the equipment, be sure the antenna or cable system

is grounded so as to provide some protection against voltage surges

and built- up static charges.

14. Lightning - For added protection for your equipment during a

lightning storm, or when it is left unattended and unused for long

periods of time, unplug it from the wall outlet and disconnect any

antenna or cable system. This will prevent damage to the equipment

due to lightning and power-line surges.

15. Power Lines - An outside antenna system should not be located

near overhead power lines or other electric light or power circuits,

or where it can fall into such power lines or circuits. When installing

an outside antenna system, extreme care should be taken to keep

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from touching such power lines or circuits, as contact with them

can seriously injure or kill you.

16. Overloading - Do not overload wall sockets or extension cords, as

this can result in fire or electric shock.

17. Object and Liquid Entry - Never push objects of any kind into

equipment through openings as they may touch dangerous voltage

points or short-out parts that could result in damaged equipment,

fire or electric shock. Never spill liquid of any kind on the equipment.

18. Servicing - Do not attempt to service equipment yourself unless you

are qualified to do so. Opening or removing covers may expose

you to dangerous voltages or other hazards. Refer all servicing to

qualified service personnel.

19. Damage Requiring Service - Unplug this product from the wall

outlet and refer servicing to qualified service personnel under the

following conditions:

a) When the power-supply cord or plug is damaged.

b) If liquid has been spilled, or objects have fallen into the equipment.

c) If the equipment has been exposed to rain or water.

d) If the equipment does not operate normally by following the

operating instructions.

e) If the equipment has been dropped or damaged in any way.

f) When the equipment exhibits a distinct change in performance

- this indicates a need for service.

20. Adjust only those controls that are covered by the operating

instructions. Improper adjustment of other controls may result in

damage and will often require extensive work by a qualified

technician to restore the equipment to its normal operation.

21. Replacement Parts - When replacement parts are required be sure

the service technician has used replacement parts specified by the

manufacturer or that have the same characteristics as the original

part. Unauthorised substitutions may result in fire, electric shock or

other hazards.

22. Safety Check - Upon completion of any service or repairs to this

product, ask the service technician to perform safety checks to

determine that the equipment is in proper operating condition.

23. Wall or Ceiling Mounting - The equipment should be mounted to a

wall or ceiling only as recommended by the manufacturer.

24. Heat - The equipment should be situated away from heat sources

such as radiators, heat registers, stoves or other products (including

amplifiers) that produce heat.

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100

Keeping your audio recordings and reference materials neatly

arranged and categorised is a very important part of the

maintenance process. Libraries such as this one make locating

archived programmes and raw recordings an easy process.

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101

ASSESSING TRAINING REQUIREMENTS

Chapter 8

Now that we've had a look at the responsibilities involved in maintaining

equipment in good order, it's time to ask ourselves an important question: What

are the technology related training requirements required for our CR station?

(Of course, your station staff may require a variety of inputs and capacity

building measures in terms of running/managing a station, mobilizing the

local community whom the station addresses, and developing a feedback

mechanism that allows the incorporation of listeners' opinions into the stations'

programming. But for the moment, we will confine ourselves to the question

of technology related training, as that is the primary focus of this manual.)

The first step to assessing your technological training requirements is, of

course, to ask yourself what level the various members of your team are at

(with reference to their ability to interact with technology):

1. Absolute novice (no idea regarding equipment, operation or repair)

2. Trainee (Has some understanding of practical usage of equipment, but

must be accompanied by more experienced people)

3. Operating level (can operate equipment comfortably and competently);

4. Expert operating level (can operate equipment and can fix common

operating issues and make fine adjustments to the equipment if required)

5. Basic Repair level (can fix most simple problems in equipment easily)

6. Advanced repair level (can handle advanced electronic repair equipment

and has an excellent understanding of circuits, circuit diagrams, soldering,

and electronic theory.)

A technical training in progress. CR volunteers learn how

to install and setup software on their editing system.

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102

Assessing training needs

Technical training can also be of different types: How to operate various

kinds of equipment of software; how to make common repairs on studio or

field equipment; or even electrical repairs and maintenance To assess the

type of technical training that you and your team require, you will first have

to answer the following questions:

1. Are there any community members who have any knowledge of

electronics, electricals and/or equipment repair that we can access

readily? (If so, what kind of skills do they have, and will they be willing to

volunteer their expertise to the CR station?)

2. What kind of equipment are we going to install in the CR station? Will the

station staff need any training to operate this equipment? Will this

equipment have any simple components or pieces that we can maintain

on our own within the staff?

3. Are there any equipment repair shops or service centers nearby which

can undertake some of the simple maintenance responsibilities? If yes,

can this service center/repair shop train some of the CR staff in basic

repairs?

4. What kind of advisers and training facilities can we access outside the

immediate community? (Are there any courses or service trainings offered

by equipment suppliers which are relevant to our setup and equipment?)

5. Can we work out a training process with whoever installs the equipment

and sets up the studio for us? What kind of trainings can these be?

(Installation/Operation/maintenance/simple repairs/complex repairs?)

How many such trainings can be arranged - and where?

6. What are the points to consider when we budget for trainings to address

these needs?

7. Can we hire a specialist repair and maintenance technician to run the

repair and maintenance process, or will this have to be an additional

responsibility for management or an identified member within the staff?

8. Will we undertake the training of fresh volunteers and technical staff

ourselves, or will we access outside resource persons or organizations

for this? (That is: Will we become technical master trainers ourselves, or

will we just learn what needs to be done and outsource the training

process?)

It is important to remember that it is almost impossible to become experts at

everything - being a service technician requires several years of training and

an expert understanding of electronics, for instance.

It is also wise to recognize that your training requirements will be different at

different points in time; and that training is likely to be a continuous part of

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103

the process of running a CR station: At the beginning, you may have to

access training from outside the immediate community; and you might like

to get the kind of training that lets you get the station off the ground and

running quickly - an important consideration given that CR guidelines in

India state that the station must be broadcasting within three months of

obtaining the Grant of Permission agreement. (Given that you are unlikely to

actually acquire equipment and set up the studios before your application

crosses the first set of clearances from the various ministries - see the guidelines

in next chapter - this actually doesn't leave you with very much time for the

set of trainings!)

CR volunteers from Mandakini Ki Awaaz CR in Uttarkhand

conduct an internal training for other members of the group.

Technical and production training must be a continuous process.

Later in the process, you may establish a sustained programme that lets the

senior members of the team take on some of the training processes themselves,

as they will now be reasonably familiar with the equipment and operation.

Building an internal training process also has the advantage of being low

cost, from the station's perspective - outside trainers may charge you for

their expertise - and sustainable, as skills acquired by staff can be passed on

and preserved even if they leave.

It is important, therefore, to create a combination training plan that keeps in

mind the available skills and the requirements of the CR station in the long

term, in this fashion:

1. Initial training: The training of the core personnel/volunteers and

producers of the CR station just before it commences operations;

2. On-going training: The continual training process of staff as new members

join and old ones leave; and as equipment, technologies and content

production techniques change.

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Training resources

Many training resources in the form of manuals and guides (like the one you

are reading, for instance) or online internet based articles are readily

accessible if you are willing to do some research . Several organizations also

run online training courses on various aspects of content production and

equipment handling.

For a basic list of online web based resources on radio and community radio

technology, see Appendix 5: Useful Web-based Resources on Page 265

Several organizations and individuals also provide training in radio, radio

programming, radio technology and station setup. Some of them can provide

an entire package of services that can help your team develop a CR station

from scratch, and assist you through to your first few months on air.

For a list of organizations and individuals with experience in working on

community radio, radio programming, station setup and equipment setup,

see Appendix 3: Index of Advisory Organizations & Individuals on Page 254

It may be a good idea to discuss the trainings that staff from other CR stations

have attended or been a part of, including the kind of advisers and trainers

that they have had in the past. This may give you a few clues regarding

where you can access training, and who from. Last but not least, it will

probably give you an idea of whether the training the other station's staff

received was any good - because it should reflect in the way that station runs

its operations and produces programmes!

A CR group volunteer conducts a demonstration at a

local school. Planning ahead often means grooming

young people who can bring energy, dynamism and

hard work to the station.

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COMMUNITY RADIO GUIDELINES IN INDIA

AND THEIR IMPLICATIONS

Chapter 9

In this chapter, we'll see the entire CR guidelines issued by the Govt. of

India when it permitted the setting up of CR stations in November 2006.

While a large portion of the guidelines are not related specifically to the

technology of community radio, there are a few clauses that do specify

certain parameters that have to be followed. Use this entire text as a reference

for the guidelines and for the application procedure. The sections that

have technological implications have notes inserted to explain and clarify

what the implications are.

Policy Guidelines for setting up Community Radio Stations in

India

Foreword

In December 2002, the Government of India approved a policy for the grant

of licenses for setting up of Community Radio Stations to well established

educational institutions including IITs/IIMs.

The matter has been reconsidered and the Government has now decided to

broad base the policy by bringing 'Non-profit' organisations like civil society

and voluntary organisations etc under its ambit in order to allow greater

participation by the civil society on issues relating to development & social

change. The detailed policy guidelines in this regard is given below:

1. Basic Principles

An organisation desirous of operating a Community Radio Station (CRS)

must be able to satisfy and adhere to the following principles:

a) It should be explicitly constituted as a 'non-profit' organisation and should

have a proven record of at least three years of service to the local

community.

b) The CRS to be operated by it should be designed to serve a specific

well-defined local community.

c) It should have an ownership and management structure that is reflective

of the community that the CRS seeks to serve.

d) Programmes for broadcast should be relevant to the educational,

developmental, social and cultural needs of the community.

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e) It must be a Legal Entity i.e. it should be registered (under the registration

of Societies Act or any other such act relevant to the purpose).

2. Eligibility Criteria

(i) The following types of organisations shall be eligible to apply for

Community Radio licences:

a) Community based organisations, which satisfy the basic principles

listed at para 1 above. These would include civil society and

voluntary organisations, State Agriculture Universities (SAUs), ICAR

institutions, Krishi Vigyan Kendras, Registered Societies and

Autonomous Bodies and Public Trusts registered under Societies

Act or any other such act relevant for the purpose. Registration at

the time of application should at least be three years old.

b) Educational institutions

(ii) The following shall not be eligible to run a CRS:

a) Individuals;

b) Political Parties and their affiliate organisations; [including students,

women's, trade unions and such other wings affiliated to these

parties.]

c) Organisations operating with a motive to earn profit;

d) Organisations expressly banned by the Union and State

Governments.

3. Selection Process & Processing of the applications

(a) Applications shall be invited by the Ministry of I&B once every year

through a national advertisement for establishment of Community

Radio Stations. However, eligible organisations and educational

institutions can apply during the intervening period between the

two advertisements also. The applicants shall be required to apply

in the prescribed application form along with a processing fee of

Rs.2500/- and the applications shall be processed in the following

manner:

i) Universities, Deemed Universities and Government run

educational institutions will have a single window clearance by

putting up cases before an inter-ministerial committee chaired by

Secretary (I&B) for approval. No separate clearance from MHA &

MHRD shall be necessary. Once the WPC Wing of the Ministry of

Communication & IT earmarks a frequency at the place requested

by the institution, a Letter of Intent (LOI) shall be issued.

ii) In case of all other applicants, including private educational

institutions, LOI shall be issued subject to receiving clearance

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from Ministries of Home Affairs, Defence & HRD (in case of

private educational institutions) and frequency allocation by

WPC wing of Ministry of Communication & IT.

Notes

The application for permission to set up a CRS is available on the Govt. of India's

Ministry of Information & Broadcasting's website (http://mib.nic.in/CRS/

CRSmainpg.htm). This is the CR related link, and contains detailed FAQs and

guidelines, as well as the status of applications pending with the Ministry.

The application requires the attachment of a variety of background documents that

prove the authenticity of your organization and its work within the community the

CRS will address. It also requires the completion of some proposed site related

data, and the attachment of a map on which you are expected to mark the site of the

CR station and antenna mast/tower. This can be a simple map, even hand drawn,

that gives a broad idea of the surrounding area and the location of your CRS.

The application must be filed with the office of the Under Secretary (FM) at the

Ministry for Information & Broadcasting.

Notes

The process of verification of the applicant's antecedents and background is

conducted through an Intelligence Bureau (IB) enquiry ordered by the Ministry

for Home Affairs, and through the local police department. This usually involves

a visit by an IB person, who may inspect your records and ask for various

background details regarding your operation, current projects and the details

included in your application form.

Subsequently, the authorized representative of the applying organization will

also be invited to make a presentation to a Community Radio screening committee

at the Information & Broadcasting Ministry's offices in New Delhi. The presentation

should give the background on the organization and the reasons for applying for

a CR license. This is usually followed by an interview/question-and-answer

Contd...

(b) A time schedule for obtaining clearances as below shall be prescribed:

i) Within one month of receipt of the application in the prescribed

form, the Ministry of I&B shall process the application and either

communicate to the applicant deficiencies, if any, or will send the

copies of the application to the other Ministries for clearance as

prescribed in para 3(a)(i) and 3(a)(ii) above, as the case may be.

ii) The Ministries concerned shall communicate their clearance within

three months of receipt of the application. However, in the event

of the failure of the concerned ministry to grant the clearance

within the stipulated period of three months, the case shall be

referred to the Committee constituted under the Chairmanship of

Secretary (I&B) for a decision for issue of LOI.

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session where you may be asked detailed questions regarding your application

and the need for a CR station in your area for the proposed community. The

panel for the screening committee is composed of civil society representatives as

well as government representatives.

iii) In the event of more than one applicant for a single frequency at a

given place, the successful applicant will be selected for issue of LOI

from amongst the applicants by the Committee constituted under the

Chairmanship of Secretary (I&B) on the basis of their standing in the

community, the commitment shown, the objectives enunciated and

resources likely to be mobilized by the applicant organisation as well

as its credentials and number of years of community service rendered

by the organisation.

iv) Within one month of the issue of the Letter of Intent (LOI) the eligible

applicant will be required to apply, in the prescribed format and with the

requisite fee, to the WPC Wing of the Ministry of Communication & IT,

Sanchar Bhawan, New Delhi for frequency allocation & SACFA clearance.

Notes

One of the primary questions that CRS applicants need to ask themselves is -

when do we actually buy the equipment we need and set up the physical station

premises? The answer to that is: When you receive the Letter of Intent, because

once you receive this, your application is on reasonably safe ground. There is still

the chance that the WPC and SACFA clearance may not be forthcoming - see

below - but this is primarily a greater issue for CR stations in urban areas. To buy

equipment before the LoI is a distinct risk.

It also makes sense to start setting up your equipment and station at this point,

because officially, you are just 6 - 8 months from here to going to air: You are

expected to commence broadcast within 3 months of receiving the Grant of

Permission Agreement that follows WPC and SACFA clearance. That's usually

too short a period to set up, test and start using transmission equipment. Buying

equipment at the LoI stage gives you the time to do this properly.

Of course, this discussion assumes that activities like mobilizing the community

and establishing a volunteer based staff for the CRS are already complete or

ongoing - that is something you definitely will not be able to complete even if you

start those activities when you receive the LoI!

v) A time frame of six months from the date of application is prescribed for

issue of SACFA clearance. In the event of non-receipt of such clearance

from the Ministry of Communication & IT within the stipulated period of

six months, the case will be referred to the Committee constituted under

the Chairmanship of Secretary (I&B) for a decision.

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Notes

The WIRELESS PLANNING & COORDINATION (WPC) Wing of the Ministry

of Communications is the National Radio Regulatory Authority responsible for

Frequency Spectrum Management, including licensing and caters to the needs of

all wireless users (Government and Private) in the country. It exercises the statutory

functions of the Central Government and issues licenses to establish, maintain

and operate wireless stations. WPC is divided into major sections like Licensing

and Regulation (LR), New Technology Group (NTG) and Standing Advisory

Committee on Radio Frequency Allocation (SACFA). SACFA makes the

recommendations on major frequency allocation issues, formulation of the

frequency allocation plan, making recommendations on the various issues related

to International Telecom Union (ITU), sorting out of problems referred to the

committee by various wireless users, and issuing siting clearance of all wireless

installations in the country.

Based on WPC records, official policy and existing stations and plans for future

expansion, these bodies decide whether your application for a transmitter of a

particular strength and a mast of a particular height can be permitted - especially

in cases where more than one CRS may be set up to address different communities

within overlapping or congruous geographical areas. WPC also decides whether

your transmitter meets specifications as per the ITU-R broadcast guidelines and is

responsible for the allocation of your station's frequency.

It may be wise to remember that the WPC can also decide to reduce the power

of your station in order to prevent overlaps with other stations nearby, and to

refuse frequency allocation altogether if too many stations have been set up

already in your proposed geographical area of work. (This issue is set to become

extremely acute in the near future in urban and peri-urban areas, where commercial

and campus FM radio stations have already been allocated a number of stations

and frequencies, leaving little space for new CR stations.)

SACFA clearance applications can ONLY be filed online on the WPC website -

www.wpc.dot.gov.in. The process involves registering yourself as a user and

logging in with your user identity and password; completing the form (which

includes details regarding the fee that has to be paid by Demand Draft to WPC,

so it's a good idea to make the DD before you sit down to apply!); getting an

online application number; and submitting a hard copy of the completed

application along with the fee demand draft to WPC. Details are given on the

WPC website itself, including a step-by-step guide for applying parties. The

website can also be used to track the status of your application at any given point

in time.

The SACFA clearance application also involves the submission of a second map

of the geographical area where the proposed station will be located, clearly

indicating the station's own location within this area. The primary consideration

for this map is that there should be latitude and longitude markings on it that help

to identify the precise position of the CRS. While a Survey of India map is ideal for

Contd...

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this purpose, it is likely to be expensive and may not be easy to access for

everyone. The WPC is therefore willing to accept even commercially available

maps in the 1:100,000 or better (1:50000) scale - the more the detail, the better

- with latitude and longitude marked on the map by a qualified geographer or

architect.

WPC is also responsible for deciding the spectrum usage fee for each station, a fee

levied by the Govt. of India for the right to use specific bands of the radio

spectrum for broadcasting. While there has been much debate on this with

regard to CR stations, this is a necessary reality that you will have to plan for: A

100 Watt ERP transmission system in the plains area, with a reach of 5 - 12 kms

is likely to pay an annual fee of Rs.19700 to the DoT for spectrum usage.

Remember that just because the guidelines mention 100W ERP transmission -

with a possibility of 250W ERP setups in certain geographical conditions - and a

30 metre mast, it doesn't necessarily mean you have to apply for the maximum

possible: If your coverage area crosses the 25 km range, the annual spectrum fee

becomes approximately Rs.36000!

vi) On receipt of SACFA clearance (a copy of which shall be submitted

by the applicant), the LOI holder shall furnish a bank guarantee in

the prescribed format for a sum of Rs.25, 000/-. Thereupon, the LOI

holder will be invited to sign a Grant of Permission Agreement

(GOPA) by Ministry of I&B, which will enable him to seek Wireless

Operating License (WOL) from the WPC Wing of the Ministry of

Communication & IT. The Community Radio Station can be made

operational only after the receipt of WOL from the Ministry of

Communication & IT.

vii) Within three months of receipt of all clearances i.e signing of GOPA,

the Permission Holder shall set up the Community Radio Station

and shall intimate the date of commissioning of the Community

Radio Station to the Ministry of I&B.

viii) Failure to comply with time schedule prescribed above shall make

the LOI/GOPA holder liable for cancellation of its LOI/GOPA and

forfeiture of the Bank Guarantee.

4. Grant of Permission Agreement conditions

i) The Grant of Permission Agreement period shall be for five years.

ii) The Grant of Permission Agreement and the Permission letter will be

non-transferable.

iii) No permission fee shall be levied on the Permission Holder.

However, the Permission Holder will be required to pay the

spectrum usage fee to WPC wing of Ministry of Communication

& IT.

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iv) In case the Permission Holder does not commence his broadcasting

operations within three months of the receipt of all clearances or

shuts down broadcasting activity for more than 3 months after

commencement of operation, its Permission is liable to be cancelled

and the frequency allotted to the next eligible applicant.

v) An applicant/organisation shall not be granted more than one

Permission for CRS operation at one or more places.

vi) The LOI Holder shall furnish a bank guarantee for a sum of Rs.25,000/-

(Rupees twenty five thousand) only to ensure timely performance of

the Permission Agreement.

vii) If the Permission Holder fails to commission service within the

stipulated period, he shall forfeit the amount of bank guarantee to

the Government and the Government would be free to cancel the

Permission issued to him.

5. Content regulation & monitoring

i) The programmes should be of immediate relevance to the community.

The emphasis should be on developmental, agricultural, health,

educational, environmental, social welfare, community development

and cultural programmes. The programming should reflect the special

interests and needs of the local community.

ii) At least 50% of content shall be generated with the participation of

the local community, for which the station has been set up.

iii) Programmes should preferably be in the local language and dialect(s).

iv) The Permission Holder shall have to adhere to the provisions of the

Programme and Advertising Code as prescribed for All India Radio.

v) The Permission Holder shall preserve all programmes broadcast by

the CRS for three months from the date of broadcast.

Contd...

Notes

As discussed previously in the manual, this clause refers to the mandatory

requirement that every CRS preserve recordings of its broadcasts over the 3

months preceding any given day of operation.

This means we have to record our broadcasts on a continual basis, with recordings

older than 3 months junked or erased simultaneously to make space for new

recordings.

Thus, if today is the 1st of June, at this point in time, we will have to be in

possession of broadcast recordings from the 1st of March onwards, so that we

have three complete months of programmes - March, April and May - on file.

Tomorrow, on the 2nd June, we can erase programmes recorded on the 1st of

March, as the three month clause means we need to have recordings starting on

the 2nd of March.

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The three month archiving system is mandated in order for the government - or

any mandated authority vested with the power of investigating complaints against

the programming generated by the CR station - to be able to call for and listen to

a copy of the programme in question. (If programmes are not preserved, they

would be broadcast and would then be lost forever, making such a process of

investigation and adjudication impossible.) The implications for the CRS of this

clause are that it has to set up an efficient archiving system that records the on air

broadcast and preserves it on a storage medium that will not call for too much

physical space.

At its simplest, the on-air programming can be recorded on cassette tape, clearly

marked with day and date, and stored in a 'library' - which essentially needs to be

no more than a cupboard that can store a reasonably large number of tapes. (At

60 minutes per tape, make an estimation of the number of tapes that will mean:

Even two hours of programming a day means 2 hours/2 tapes x 30 days x 3

months = 180 tapes!)

Modern digital audio - if the CRS can afford it - can make this process less

cumbersome, as digital storage essentially means recording on air programming

directly onto a hard disk. Compression technology allows us to store good quality

audio in relatively little space, and hard disks are becoming cheaper every day.

So a single 500 Gigabyte hard disk should comfortably store nearly

500 x 1000 = 500000 minutes of broadcast quality programming: More than

8000 hours of programming!

Of course, the thing to remember with such a dedicated archiving computer is that

there should be provisions to regularly back up the material that it is recording, so

that a single system failure does not wipe out a large quantity of programming. This

is especially significant assuming that you want to go beyond the three month

regulation and store programming on an ongoing basis. (This is not required under

the guidelines, but is good practice as a CRS, since you may reuse programming

later, and be able to share it with other CR stations, with or without compensation.)

It is therefore a good idea to equip such a system with a DVD writer, so that

accumulated programming can be written to DVDs at intervals, and preserved

off-system. DVDs don't take up much space in their slim cases, and if treated well,

can be a long term storage method.

vi) The Permission Holder shall not broadcast any programmes, which

relate to news and current affairs and are otherwise political in nature.

vii) The Permission Holder shall ensure that nothing is included in the

programmes broadcast which:

a. Offends against good taste or decency;

b. Contains criticism of friendly countries;

c. Contains attack on religions or communities or visuals or words

contemptuous of religious groups or which either promote or result

in promoting communal discontent or disharmony;

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d. Contains anything obscene, defamatory, deliberate, false and

suggestive innuendoes and half truths;

e. Is likely to encourage or incite violence or contains anything against

maintenance of law and order or which promote-anti-national

attitudes;

f. Contains anything amounting to contempt of court or anything

affecting the integrity of the Nation;

g. Contains aspersions against the dignity of the President/Vice

President and the Judiciary;

h. Criticises, maligns or slanders any individual in person or certain

groups, segments of social, public and moral life of the country;

i. Encourages superstition or blind belief;

j. Denigrates women;

k. Denigrates children.

l. May present/depict/suggest as desirable the use of drugs including

alcohol, narcotics and tobacco or may stereotype, incite, vilify or

perpetuate hatred against or attempt to demean any person or group

on the basis of ethnicity, nationality, race, gender, sexual preference,

religion, age or physical or mental disability.

viii) The Permission Holder shall ensure that due care is taken with

respect to religious programmes with a view to avoid:

a) Exploitation of religious susceptibilities; and

b) Committing offence to the religious views and beliefs of those

belonging to a particular religion or religious denomination.

6. Imposition of penalty/revocation of Permission Agreement

(i) In case there is any violation of conditions cited in 5(i) to 5(viii),

Government may suo motto or on basis of complaints take

cognisance and place the matter before the Inter-ministerial

Committees on Programme and Advertising Codes for

recommending appropriate penalties. On the recommendation of

the Committee a decision to impose penalties shall be taken.

However, before the imposition of a penalty the Permission Holder

shall be given an opportunity to represent its case.

(ii) The penalty shall comprise of:

(a) Temporary suspension of Permission for operating the CRS for a

period up to one month in the case of the first violation

(b) Temporary suspension of Permission for operating the CRS for a

period up to three months in the case of the second violation

depending on the gravity of violation.

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Besides, the Permission Holder and its principal members shall

be liable for all actions under IPC, CrPC and other laws.

(iii) In case of revocation of Permission, the Permission Holder will not

be eligible to apply directly or indirectly for a fresh permission in

future for a period of five years.

"Provided the penalty imposed as per above provision shall be

without prejudice to any penal action under applicable laws

including the Indian Telegraph Act 1885 and Indian Wireless

Telegraphy Act 1933, as modified from time to time."

(iv) In the event of suspension of permission as mentioned in para 6 (ii)

(a) & (b), the permission holder will continue to discharge its

obligations under the Grant of Permission Agreement during the

suspension period also.

7. Transmitter Power and Range

i) CRS shall be expected to cover a range of 5-10 km. For this, a

transmitter having maximum Effective Radiated Power (ERP) of 100

W would be adequate. However, in case of a proven need where the

applicant organisation is able to establish that it needs to serve a

larger area or the terrain so warrants, higher transmitter wattage with

maximum ERP up to 250 Watts can be considered on a case-to-case

basis, subject to availability of frequency and such other clearances

as necessary from the Ministry of Communication & IT. Requests for

higher transmitter power above 100 Watts and upto 250 Watts shall

also be subject to approval by the Committee constituted under the

Chairmanship of Secretary, Ministry of Information & Broadcasting.

Contd...

Notes

The strength of a transmitter, like the power in an electrical circuit, is measured

in Watts. Essentially, this refers to the amount of electrical energy that it converts

to radio wave (or electromagnetic) energy. Thus, a 30 Watt transmitter would

consume a little more than 30 Watts of electricity - there is some internal loss in

the system, and the conversion is not 100% efficient - and give an output of

roughly 30 Watts worth of electromagnetic energy.

However, it is important to remember that just the transmitter's output does not

tell us the station's output strength, because the actual strength - or Effective

Radiated Power, ERP - is a combination of the transmitter's strength and the

amount this is magnified by the antenna we use. (The magnification is called

'gain', and this is a natural property of the antenna based on the materials it is

constructed out of and its physical structure and shape. It is also directional in

nature, with the gain - and therefore the ERP - varying at different points with

reference to the antenna.)

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Essentially, this means that the sum total of the two - the net strength of our

station, as it were - must be a maximum of 100 Watts, with 250 Watts allowed

in geographically difficult areas. Practically, this means if we select the correct

combination of transmitter and antenna, our actual transmitter strength can be as

low as 30 Watts, since gains of 3x (3 times the transmitter strength) are easily

achievable through many antennae.

At the same time, we must factor in losses of signal strength caused by the cables

connecting the studio to the transmitter, and the transmitter the antenna, which

can also be an important consideration, especially if the transmitter has to be

located at a little distance from the studio.

As noted earlier, please be aware that these are merely wattages and limits

specified by the Govt. guidelines - whether you actually are allowed a transmitter

of a specific output, or a mast of a particular height is dependent on WPC and

SACFA clearance, as seen above.

Notes

As discussed earlier in the manual, keeping the antenna high off the ground not

only prevents it from being accidentally obstructed, but also gives the antenna a

vantage point from which it can broadcast over a larger area.

This clause states that the metal pole or antenna tower on which the antenna is

mounted for this purpose - the antenna unit itself is only a couple of feet long in

most cases - can be a maximum of 30 metres high. It also states that the antenna

must be at least 15 metres off the ground to safeguard against any radiation

hazards caused by the electromagnetic energy emanating from it.

What you must remember is that this in no way restricts you from installing the

antenna on a hillock or mountain overlooking your potential broadcast area as

long as this falls within the space where your listener community resides, and

considerations of equipment and studio location allow this (see the section on

Studio Transmitter Links). Thus, even with the height restriction this clause imposes,

you can actually get a much larger broadcast area if you can exploit some natural

formations in your geographical area.

It is also a good idea to take advantage of building height if possible: If you install

a 15 metre antenna on a 15 metre building, remember that you are actually

getting the advantage of a 30 metre height with half the actual mast length.

ii) The maximum height of antenna permitted above the ground for the

CRS shall not exceed 30 meters. However, minimum height of

Antenna above ground should be at least 15 meters to prevent

possibility of biological hazards of RF radiation.

iii) Universities, Deemed Universities and other educational institutions

shall be permitted to locate their transmitters and antennae only within

their main campuses

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iv) For NGOs and others, the transmitter and antenna shall be located

within the geographical area of the community they seek to serve.

The geographical area (including the names of villages/institution

etc) should be clearly spelt out along with the location of the transmitter

and antenna in the application form.

Notes

Taking off from the point above, this clause specifies that you cannot install your

antenna mast or tower on any convenient location just because it affords you a

bigger broadcast area: It has to be in an area that falls within the space occupied

by your potential listener community. In hilly regions, of course, the population

may be sparse, and distributed up and down valleys or both sides of a hill or

mountain. In such cases, we have relatively greater flexibility to decide the best

placement of the antenna tower, as the definition of what constitutes the listener

community's geographical area is rather hard to define exactly.

8. Funding & Sustenance

i) Applicants will be eligible to seek funding from multilateral aid

agencies. Applicants seeking foreign funds for setting up the CRS will

have to obtain FCRA clearance under Foreign Contribution Regulation

Act, 1976.

Notes

Please remember that this means if you access funding from a donor agency to

purchase equipment and/or set up your CR station, the wording of the policy

suggests that funding can only be obtained through UN agencies or international

aid agencies that are not part of the bilateral government-to-government aid

system.

Also, this means that accessing funds - whether in cash or in equipment form - is

governed by Foreign Currency Regulation Act norms. If your organization does

not have permanent registration with the FCRA authorities, it may have to apply

for 'prior permission' clearance for the funds or in kind assistance that it hopes to

access. This process takes time, and must be factored in when planning the

station setup and/or equipment purchases. Consult a good chartered accountant

to figure out this process if you think you need help on this.

Note that United Nations funding is not governed by FCRA regulations.

ii) Transmission of sponsored programmes shall not be permitted

except programmes sponsored by Central & State Governments and

other organisations to broadcast public interest information. In

addition, limited advertising and announcements relating to local

events, local businesses and services and employment opportunities

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shall be allowed. The maximum duration of such limited

advertising will be restricted to 5 (Five) minutes per hour of

broadcast.

iii) Revenue generated from advertisement and announcements as

per Para 8 (ii) shall be utilized only for the operational expenses

and capital expenditure of the CRS. After meeting the full financial

needs of the CRS, surplus may, with prior written permission of

the Ministry of Information & Broadcasting, be ploughed into

the primary activity of the organization i.e. for education in case

of educational institutions and for furthering the primary

objectives for which the NGO concerned was established.

9. Other Terms & Conditions

i) The basic objective of the Community Radio broadcasting would

be to serve the cause of the community in the service area of the

Permission Holder by involving members of the community in

the broadcast of their programmes. For this purpose community

shall mean people living in the zone of the coverage of the

broadcasting service of the Permission Holder. Each applicant

will have to specify the geographical community or the

community of interest it wants to cover.

The Permission Holder shall provide the services of his CRS on

free-to-air basis.

ii) Though the Permission Holder will operate the service under

these guidelines and as per the terms and conditions of the

Grant of Permission Agreement signed, the permission shall

be subject to the condition that as and when any regulatory

authority to regulate and monitor the broadcast services in the

country is constituted, the permission holder will adhere to the

norms, rules and regulations prescribed by such authority from

time to time.

iv) The Permission Holder shall provide such information to the

Government on such intervals, as may be required. In this

connection, the Permission Holder is required to preserve

recording of programmes broadcast during the previous three

months failing which Permission Agreement is liable to be revoked.

Notes

See notes on Clause 5 (V)

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v) The Government or its authorized representative shall have the right

to inspect the broadcast facilities of the Permission Holder and collect

such information as considered necessary in public and community

interest.

vi) The Government reserves the right to take over the entire services

and networks of the Permission Holder or revoke/terminate/suspend

the Permission in the interest of national security or in the event of

national emergency/ war or low intensity conflict or under similar

type of situations.

vii) All foreign personnel likely to be deployed by way of appointment,

contract, consultancy etc by the Permission Holder for installation,

maintenance and operation of the Permission Holder's services shall

be required to obtain prior security clearance from Government of

India.

viii) The Government reserves the right to modify, at any time, the terms

and conditions if it is necessary to do so, in public interest or for the

proper conduct of broadcasting or for security considerations.

ix) Notwithstanding anything contained anywhere else in the Grant of

Permission Agreement, the Government shall have the power to

direct the permission holder to broadcast any special message as

may be considered desirable to meet any contingency arising out of

natural emergency, or public interest or natural disaster and the like,

and the Permission holder shall be obliged to comply with such

directions.

x) The permission holder shall be required to submit their audited

annual accounts to the Government in respect of the organization/

division running the CRS. The accounts shall clearly show the income

and expenditure incurred and the Assets and Liabilities in respect of

the CRS.

xi) A Permission Agreement will be subject to such other conditions as

may be determined by the Government.

xii) The Government shall make special arrangements for monitoring

and enforcement of the ceiling on advertisements, particularly in

those areas where private FM radio stations have been granted

licenses.

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NOTES

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Section B

Detailed notes on equipment

& audio concepts

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TABLE OF CONTENTS

PART B: Detailed notes on equipment & audio concepts

Analog & Digital Audio ...................................................................... 124

Amplifiers .......................................................................................... 128

Balanced and Unbalanced Connections ............................................ 131

Cassette Tapes & Cassette Recorders .................................................. 134

Compact Discs ................................................................................... 138

Compact Disc Players ........................................................................ 141

Compact Disc Writers (CD Writers) .................................................... 145

Compressor / Limiters ........................................................................ 149

Computer Hardware .......................................................................... 152

Computer Software (For Radio) ........................................................... 159

Connectors (Power) ........................................................................... 163

Connectors (Audio & Telecom) .......................................................... 166

Decibels ............................................................................................. 172

Digital Playout Systems ...................................................................... 173

(Audio) Effects .................................................................................... 175

Electromagnetic Spectrum .................................................................. 177

Equalizers .......................................................................................... 179

(Acoustic) Feedback ........................................................................... 182

Field Recorders .................................................................................. 184

Flash Recorders ................................................................................. 187

Loudspeakers & Studio Monitors ....................................................... 190

Magnetic Recording ........................................................................... 193

Meters & Audio Level Measurement .................................................. 195

Microphones ..................................................................................... 198

Minidiscs & Minidisc Recorders ......................................................... 204

Mixers & Mixing Desks ...................................................................... 207

Modulation ........................................................................................ 209

Patchbays .......................................................................................... 212

Signal to Noise Ratio .......................................................................... 214

Sound & Audio .................................................................................. 215

Stereo & Mono .................................................................................. 217

Telephone Hybrids ............................................................................ 220

Transmitters ....................................................................................... 222

Uninterrupted Power Supply (UPS) .................................................... 224

Generators ......................................................................................... 229

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ANALOG & DIGITAL AUDIO

Sound travels as a series of waves - that is, as a continuous rise and fall in the

pressure of the air at a given point in space. When we speak, our vocal

chords vibrate at various frequencies, creating corresponding vibrations in

the air around them. These vibrations - waves - are then transmitted by the

particles that make up air, and the vibrations are passed along till they reach

someone else's ears…or a microphone that is designed to pick up these

vibrations.

For more on microphones, see Section B: Microphones on Page 198

Analog Audio

The microphone, in turn, converts these vibrations into an electrical signal,

that rises and falls in exact correspondence with the rises and falls in the

sound wave that is reaching the microphone. If the signal is then recorded

on magnetic tape, what we have thus far is a process where a continuous

wave or signal - even if it is changing from sound energy to electrical energy

and stored as an arrangement of magnetic particles - is being preserved

throughout the entire process. Since in each case, we have a signal that is

analogous to the original sound wave that was produced, such signals are

called analog signals.

Digital audio

As technology progressed, however, new ways to store information became

available. One such technology was digital storage, where information of

any kind - visual, audio, or a combination of both - could be stored as a

series of numbers, which together represented the original information. The

information was stored usually in combinations of ones and zeros, a system

Time

Changing voltage

signal in response

Volt –

Volt +

Input Signal

(Sound)

Fig 1: An analog signal produced by a microphone in response to a

continuously changing sound

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of mathematics called binary numbers. (In fact, the fact that the storage was

in the form of numeral digits was why it began to be called digital storage in

the first place!)

Digital signals and storage offer us vast advantages over the older analog

system:

1. Digital signals can be stored more economically than analog signals

can. An LP or long playing record could store about a half hour's worth

of music per side. Today, a small digital music player the size of a

matchbox can store ten times as much.

2. Digital signals can also be manipulated more easily than analog signals,

both in terms of clearing out unwanted components, and in terms of

making changes to the signals.

3. Digital signals can also be copied and duplicated more easily: There is

no deterioration of the signal across copies, unlike what used to happen

with analog storage methods. This also applies to transmission of the

signal through cables or broadcast, where analog signals invariably pick

up some noise, but digital signals do not by virtue of the way the

information is carried in both cases.

Where audio was concerned, this presents a plethora of options, with high

quality audio becoming easily accessible to everyone: The first item of digital

audio to make it to the market was the compact disc or CD, which stores

digital data on a spinning disc of plastic encased metal.

For more on compact discs, see Section B: Compact Discs on Page 138 and

Section B: CD Writers on Page 145

Increasingly, audio recording - professional or for personal use, large radio

station or community radio station - relies on digital audio equipment.

Computers store information digitally, as do CDs, VCDs and DVDs. However,

there is a downside to using digital technology; and that has to do with the

way analog sound is converted to a digital signal by the digital sound

equipment we use.

A/D conversion

We have already seen that a sound, when it originates, is a continuously

rising and falling wave, and hence analog in nature. To convert analog

sound into a digital signal, there has to be a process where we convert the

characteristics of the sound wave into a set of equivalent numbers that

describes the wave. This process is called Analog to Digital (or A/D)

conversion, and the first step in this is called sampling.

Sampling is essentially the process of dividing the original wave up into a

series of smaller slices. Obviously, it is easier to describe each slice more

accurately than one can describe the wave as a whole. And if we then have

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Fig 2: Analog to Digital sampling

a description of the value of each slice (as an equivalent number), and a

description of that number's position in the overall list of numbers describing

the wave, it is fairly straightforward to reconstruct the original wave from

these descriptions.

The figure above shows the original wave, and slices we have made. We

can reconstruct the wave by joining the samples (dots) that we have created.

The reconstructed wave is not totally an accurate copy - it is more jagged

than the original. This is the negative side of digital technology. A/D conversion

is essentially a matter of approximation: The slices only give you an idea of

what the original analog signal was like. However, this is becoming rapidly

less of a drawback, as modern technology is using higher and higher

sampling rates to make finer and finer slices of the original signal. If we can

make the samples/slices much finer, the wave we can reconstruct from this

information becomes closer and closer in shape to the original analog wave.

It is generally accepted that if the sampling rate is twice the highest frequency

wave in the audio signal, the results of sampling will be indistinguishable to

the human ear from the original analog sound wave. This is why digital

audio on CDs are sampled at 44100 Hertz (or 44100 samples per second,

44.1 KiloHertz or KHz) - because the highest frequency detectable by the

human ear is 20000 Hz, and this is more than twice that. Digital video

recordings record sound at 48000 Hz, so their audio is a little higher in

quality. FM stations often sample the audio at 32 KHz, as the higher

frequencies - 16000 Hz and above - often get lost in the broadcast process,

and we need to be concerned with recording and reproducing audio only

upto that limit.

Data/Bit Rate

The other factor that controls the quality and accuracy of the digital signal is

the amount of information we can store about each of the samples/slices:

Time

Original

analog

signal

Volt –

Volt +

Each dot represents

a 'snapshot' or

sample of the wave

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The more information we store about each sample, the greater the accuracy

in reconstructing the original wave. In digital storage, each 1 or 0 that we use

is called a bit of information. CDs usually use 16 bit sampling - that is, 16 bits

to describe each sample. More recent pro audio equipment uses 24, 32, 48

or 96 bit sampling, leading to ever more accurate storage and retrieval.

D/A Conversion

Once the audio is stored in a digital format, we need equipment and

techniques to convert it back into the original analog sound as well. The CD

players, DVD players and MP3 music players that we see all around us

today - including the music players built into many mobile phones - perform

just this function: They convert the digital signal back into the analog signal,

a process known as D/A conversion. This is the exact reverse of the sampling

process.

As noted previously, both the sampling and the D/A conversion process

involve some loss of audio information. Some people can be sensitive to

this loss, and can 'feel' the difference between the digital version and the

analog version of the same audio recording. But increasingly, as digital

audio equipment improves, even low cost consumer grade equipment can

give you a high enough grade of storage and reproduction to satisfy the vast

majority of listeners.

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Fig 3: How an amplifier increases the level of an input signal.

AMPLIFIERS

The first step in recording and storing audio - and in sending it over cables

or any other kind of link between pieces of equipment - is to convert the

sound waves into electrical energy.

The electrical signal that is generated by transduction devices like

microphones is actually a very tiny current - so small, in fact, that you will not

even notice it is there if it weren't for the sensitive instruments and devices

we use to monitor, interpret and store it. In order to be able to effectively

store and manipulate the sound, we need to be able to raise and lower its

level - that is, make the electrical signal stronger or weaker, and thereby the

sound louder or softer.

This is achieved with a device called the amplifier. The word 'amplify'

means to increase; and this, indeed, is the primary function of an amplifier:

To increase the magnitude or size of the signal.

Gain

Gain is a measure of the amount by which an amplifier increases the size of

the electrical signal. It is measured as the ratio between the strength of the

output signal to the strength of the input signal. (A gain of 2, for example,

shows that the output signal is twice as strong as the input signal.)

The level or strength of an audio signal is measured in deciBels (dB); and

looked at another way, a gain of 2 can also be seen as an increase of 3

decibels (3dB).

Types of amplifiers

Amplifiers are one of the most essential components in a variety of audio

processing situations, which makes them of special significance when we

discuss their use in radio broadcasting.

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1. Power amplifiers

Power amplifiers are used whenever we need to raise the strength of the

signal high enough to drive a speaker: The larger the speaker, the larger the

output required of the power amplifier…and consequently the greater the

gain required of the power amplifier. Power amplifiers are often used in live

sound situations - concerts, for instance - because the speakers required for

the sound to reach a large gathering are very large.

Power amplifiers may or may not have controls of their own, though they

commonly have a knob that allows you to control the gain (output). They

also usually have connectors for a pair of speakers, and may accept a variety

of connector types depending on the specific use they are meant for.

In the radio studio, the power amplifier is usually used to feed the studio

monitor speakers. Most often, it is controlled from the mixing desk itself,

with the faders of the mixer used to adjust the input (and thereby the output)

of the amplifier.

2. Distribution amplifiers

The distribution amplifier (DA) is a type of amplifier used to keep the strength

of the signal constant across a large number of outputs when a single

source must feed multiple devices. Just as the pressure of water in a water

pipe decreases if it is connected to too many taps, the strength of a signal in

the system will fall if the same signal must be given to multiple outputs.

In the radio studio, there are usually a number of different pieces of equipment

- and they may all need to be fed the output from a single mixer. (The same

mixer may also give an output for the production studio, if the mixer in

question is in the broadcast studio - and indeed, even to the voice booth or

recording floor.) This means the signal will be greatly diminished if we just

split it up electronically and try to feed it to all these devices. This is where

the distribution amplifier comes in: The mixer output is fed to the DA, which

boosts the strength of the input signal, and feeds it to a number of outputs -

and thereby solving our problem of lowered signal strength.

In the radio studio, DAs typically have stereo inputs and a number of stereo

outputs - often 8 outputs or more - which can then be connected to stereo

recording devices and the transmission system. A low cost option would be

to keep the entire system mono, and have a DA that has mono inputs and

outputs; but these are comparatively rare as an option, since there is very

little difference in price for such a setup.

3. Headphone amplifiers

A headphone amplifier is a specialized type of distribution amplifier that is

used to connect more than one headphone to the same output.

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When a programme is being made, or a transmission is taking place, more

than one person will often need to listen to the audio output at the same

time. Connecting multiple headphones to the same headphone socket would

lead to the same situation we saw above: A weak signal that cannot be heard

properly over any of the headphones. A headphone amplifier solves this by

keeping the output to each pair of headphones constant.

Headphone amplifiers are often used in on air studios and on recording

floors where each of the guests/speakers may be required to have a pair of

headphones.

For more on headphones, see Section B: Loudspeakers & Studio Monitors

on Page 190

4. Pre-amplifiers

Pre-amplifiers are used to boost the tiny output signals that emerge from

many audio devices: Microphones, for instance, have outputs that are hardly

a few microvolts strong. Pre-amplifiers boost these outputs to a level where

they can be fed to other audio devices.

For more on microphones, see Section B: Microphones on Page 198

In many field recorders and mixers, the pre-amplifier is built into the input

into which the microphone's output will be connected. It is important for the

pre-amplifier to be of good quality, since it boosts the microphone's signal

by a large amount (meaning it will also magnify any distortions by a large

factor); and because it is the first electronic signal processing unit in the

chain (and is therefore responsible for the quality of the signal that will be fed

to all parts of the chain of electronics that follows it). A good microphone

connected to a bad pre-amplifier can ruin any advantage and quality gained

by the quality of the microphone.

It must be noted that among pre-amplifiers, the ones used for LP players

(phonographs or turntables) are a specific subtype that cannot be connected

to any other variety of equipment.

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Fig 4: A balanced connector system.

BALANCED & UNBALANCED CONNECTIONS

One of the issues with transferring weak audio signals over wires is that the

signals can be affected by any electromagnetic disturbances in the area. The

powerful electromagnetic noise generated by overhead electrical cables, a

nearby transformer field or even the Earth's own magnetic field can result in

annoying distortions of the audio, or crackle, noise or hum in the circuit.

Engineers have found a number of ways to protect the signal from these

disturbances, and chief among them is the concept of balanced and

unbalanced connectors.

Balanced connectors

Balanced connectors constitute a system that allows us to filter out unwanted

noise from the useful components of the signal.

The balanced connector system is composed of three wires: The hot and

cold wires, which both carry the signal; and a common screen wire. The

key to the entire system is that the hot and cold wires carry the same signal,

but with the polarity reversed or 'out of phase' - that is, with the peaks and

the troughs of the wave reversed, like this:

Hot

(A)

Cold

(–A)

Noise

A+n

– A+n

Noise

As the figure shows us, the combination of the out of phase signals, and the

fact that noise gets added to both wires equally allows us to output a signal

that is twice as strong (2A) as the basic input audio (A), even while we

manage to cancel out the noise (n).

Balanced connectors are found on all professional equipment - including

semi professional equipment nowadays. For the system to work properly,

the origin and receiving systems must both be balanced.

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Fig 5 : Balanced connection wiring

Unbalanced connectors

Unbalanced connectors use a two wire system where the inner (hot)

conductor wire is surrounded by an outer wire, which is often in the form of

a mesh or shield that is designed to absorb unwanted electrical disturbances.

But since the system is not designed for a cancellation process like the

balanced system is, the noise cannot be filtered out of the system.

Considerations

Owing to the effectives of the noise canceling system, balanced cables can

be as long as 500 metres or more with no loss in the quality of the signal they

carry. Unbalanced cables, on the other hand, have to be much shorter to

keep the amount of noise they pick up to a moderate level. This is why

balanced cables and connections are used in professional equipment, and

unbalanced in consumer equipment, since the latter tends to require much

shorter lengths of cable.

Balanced connections are also designed to carry a much higher signal level

(usually +4 dBm) than unbalanced connections (usually - 7.8dBm). There

are a number of equipment combinations and setups where we are required

to connect balanced and unbalanced equipment; and when a balanced

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input is connected to unbalanced equipment, we must be careful while

amplifying the signal, since it is already at a level much higher than what the

unbalanced system was designed for . Conversely, an unbalanced connector

connected to a balanced input will actually be feeding it a signal that is too

low for what it is designed for.

In such situations, the solution is to use a piece of equipment called a

balancing amplifier, that converts balanced inputs to unbalanced and vice

versa. The illustrations in this section show a variety of balanced and

unbalanced connectors, and how the wires are connected.

For more on connectors, see Section B: Connectors (Audio & Telecom) on

Page 166

Fig 6 : Unbalanced connector wiring

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CASSETTE TAPES & CASSETTE RECORDERS

Almost everyone, even in the relatively remote parts of the country, has

heard audio played off a cassette player at some point in time. The cassette

recorder has been the standard for small radio stations around the world for

a long time; and though MiniDisc recorders and solid state flash memory

recorders have increasingly begun to replace them, they still remain a useful

part of the CR station's equipment list.

The cassette recorder is an analog audio recording system, and uses a

recording system which we refer to as magnetic recording. There are two

parts to any audio magnetic recording system:

 the tape it uses as the storage medium.

 the recorder, which also acts as the playback device

The Tape

Cassette tapes - and their predecessors, the spool or reel tape - are a typical

example of the media used in magnetic audio recording systems. The three

main features of the cassette tape are the tape box, the tape ribbon and the

plastic cassette.

The box is a plastic case, usually with a hinged top that you open to remove

the tape. The lid is often of clear plastic so that you can insert labels identifying

the tape, which can then be read without opening the box.

A typical audio cassette, also known as a compact

cassette. The tape ribbon is contained in a

transparent plastic shell.

The tape (often also referred to as the ribbon) is essentially a long strip of

plastic coated with a layer of magnetic particles. If you expose these magnetic

particles to a magnetic field, they are permanently magnetized by the field

until they are exposed to a fresh field. This is the property that magnetic

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recording utilizes to store the recording on the tape. This ability gives magnetic

tape two of its most appealing features:

Firstly you can record audio instantly and the tape will "remember" what

was recorded for playback.

Secondly you can erase the tape and record something else on it.

For more on magnetic recording, see Section B: Magnetic Recording on Page 193

Tape Type & Length

Cassettes are available in of various lengths. The ones most commonly sold

in shops are 60-minute or 90-minute cassettes. A 90-minute cassette has

135 meters of tape inside it, which runs at 1 7/8th inches per second in the

recorder.

Cassettes are also usually available in three types of coatings. In increasing

order of audio quality, these are:

Ferric oxide, where the magnetic particles are actually particles of an

iron compound called ferric oxide. This is the most common type, and

the kind most cassette recorders can record on

Chrome, where particles of chromium dioxide are mixed in with the

ferric oxide

Metal tape, which uses particles of pure metal rather than an oxide

compound

Metal tapes can be played back on all cassette players, but can only be

recorded on recorders which have a special setting for metal tapes. Most

professional cassette recorders will have a small switch that lets you shift

between 'Normal' (Ferric Oxide), 'Chrome' and 'Metal' settings

The Cassette

The cassette is a fairly simple protective covering and case for the tape.

In cassettes, the tape is usually attached to and wound around two plastic

cores, two rollers and the plastic outer shell that protects the tape. (In spool

tapes, the tape ribbon is loose, and is physically wound around the core of

a plastic spool by the user.) There is also a small felt pad that keeps the tape

pressed against the the record/playback head in the tape player.

The cassette also has two protective tabs on top. When these tabs are

broken off, you can no longer record on the tape. Use a pen or something

similar to gently break the tabs when necessary. If you have broken these

tabs, but want to record onto the cassette again, you can cover the holes you

have made by covering the tab slots with two small pieces of sticky tape. Be

sure that the tape is securely stuck down, so that it cannot come loose while

inside the cassette recorder.

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Things to remember when using cassette tapes and recorders

The relatively poor quality compared to CD and reel-to-reel, and lack of editing

facility, mean many broadcasters believe cassettes are not appropriate for

regular use. Nevertheless, the cassette tape's small size and the almost universal

access to cassette tape decks in studios make it a very useful medium.

Because the tape is contained inside the cassette, compact cassettes are very

robust. However to protect your recordings, you should handle tapes with care.

Keep cassettes in their cases when not in use.

Keep tapes away from magnetic fields. The tape is a magnetic medium,

so exposing the tape to a strong magnetic field will affect the stored

sound. In the studio, computer screens and loudspeakers often have

strong magnetic fields. So leaving tapes near the computer, or on top of

a loudspeaker, is not good practice.

Always label the cassettes you are using. A fresh blank tape usually

includes a labelling sheet. People finding unlabelled cassettes lying

around in the studio may record over them, and you may lose important

sound that you will never be able to record again. Another reason is that

you may lose your cassette and it will take time to listen to a whole lot of

unmarked or poorly marked tapes to find the sound you need. Ensure

that labels and stickers identifying tapes are not loose or peeling off. The

labels can cause the tape to get stuck in the tape deck and will damage

the machine.

Most tape decks have an unbalanced stereo output, although some more

expensive broadcast tape decks have a balanced stereo output. RCA

connectors are usually used for the unbalanced output. The left and right

channels are usually colour coded, with red indicating right, and white left.

These outputs are connected to the tape channel inputs on the mixing desk.

In some instances these can be passed through a balancing amplifier before

being connected to the mixer. In some studios they may also be connected

to the studio patch panel.

Most cassette recorders and decks also have a stereo input for recording.

Again this is most often through unbalanced RCA connectors or phono

connectors. The tape deck is usually fed with audio directly from the

recording bus of the mixing desk, or via a distribution amplifier connected

to the recording bus. Some broadcast tape decks have a control input that

allows the tape-deck to be controlled from the mixer.

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Cleaning & Maintenance of cassette recorders

On the whole, however, tape recorders needs very little

maintenance. The most important thing to remember is to clean

tape heads and the compartment.

The tape heads should ideally be cleaned after every five hours

of use. To clean the heads, take a cotton wool earbud and

cleaning alcohol such as surgical spirits. Both earbuds and

surgical spirit are available from most pharmacies. After shave

lotion will work in an emergency.

Dip the earbud into the spirit so that it is moist but not dripping

wet. Then gently rub the earbud over the heads in the tape deck.

Avoid touching the plastic and rubber parts of the device with

the spirit.

The main dirt that collects in the compartment will be dust and

fluff. It is difficult to avoid getting dust in the compartment, but

you can minimise the problem by keeping the compartment

closed when not in use and by regularly cleaning the studio.

If you see any bits of fluff or other dirt, gently pull them out using

a pair of tweezers.

Most tape decks come with a noise reduction system to minimise

unwanted noise during recording and playback. Dolby Noise

Reduction is the most common system. Using the Dolby system

properly will improve tape sound quality. For the best results, a

recording made using a noise reduction system must be played

back using the same system. If your station chooses to use noise

reduction, then all the tape decks in the station need to be set to

use the same noise reduction system.

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COMPACT DISCS

The compact disc is a digital audio medium. The disc stores stereo 16-bit

audio sampled at 44.1 KHz. As an industry specification developed when

CDs were invented, CDs can record 74 minutes 33 seconds of audio at this

quality, although many newer CDs store up to 80 minutes. In terns of the

amount of digital data that can be stored on a CD, this translates to 650

Megabytes (MBs) of information (700 MB for newer CDs).

Prerecorded audio CDs contain audio items such as songs organised into

tracks, with each track identified by a track number. However, CDs can also

contain digital data of other kinds, in which case they may be seen as files,

much as you can see them on a computer's hard disk. If the CD contain

audio in other digital audio formats like mp3 or wav, this audio data will not

be seen as tracks, but as data files.

A CD is only 120mm (millimetres) in diameter and about 1.2 mm thick. Most

of a CD consists of a piece of clear polycarbonate plastic. During

manufacturing, this plastic is impressed with microscopic bumps, arranged

as a single, continuous, extremely long spiral track of data. These bumps

mark the binary numbers, that is, the 1's and 0's (bits), which make up the

digital audio on the disc. In the case of a data CD that is used in a computer,

the bumps mark the bits that make up the data files stored on the CD. In all

other respects it works in exactly the same way.

Once the clear piece of polycarbonate is formed, it is covered with a

thin, reflective aluminium layer. A thin acrylic layer is then sprayed over

the aluminium to protect it. The label and artwork is then printed on

the acrylic.

Fig 7 : Cross Section of a CD

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The data track on the CD spirals outwards from the centre to the edge. The

data tracks are extremely small and are measured in microns. A micron is a

millionth of a metre. The data track is about 0.5 microns wide, and the gap

separating one track from the next is only 1.6 microns wide. The bumps that

make up the track are each only 0.5 microns wide, a minimum of 0.83

microns long and 125 nanometers high. (A nanometer is a billionth of a

meter.) The microscopic sizes of the bumps make the spiral track on a CD

extremely long. If you could lift the data track off a CD and stretch it out into

a straight line, it would be 0.5 microns wide and over 5.5km long!

Reading the CD data

To read something this small requires an extremely accurate disc-reading

mechanism. A CD player uses a low power laser to read the data track from

the disc. A laser (Light Amplification by Stimulated Emission of Radiation) is

a beam of intense light of a specific wavelength which can be focused and

controlled very precisely. A motor unit spins the disc in the player and a

sensitive tracking system keeps the laser beam focused on the spiral data

track. The laser shines through the polycarbonate layer onto the aluminium

backed data track. The shiny aluminium layer reflects the laser light back off

the surface of the disc. The light is either reflected straight off the aluminium,

or is deflected off a bump in the data track. The CD player detects these

differences. It registers the light deflected off a bump as a 1, and light that is

not deflected (the reflected light) as a 0. In this way, the CD player creates the

stream of digital information that can be converted into an audio signal. The

digital information on the CD is coded to ensure that as long as the CD is

well looked after, it will work perfectly.

The CD also contains other digital data, called sub-code. The sub-code

contains a Table of Contents that organises the data on the CD. The sub-

code also contains information about the tracks on the CD, such as the

number of tracks and their duration. The sub-code makes it possible to find

different tracks on the CD easily, and allows the CD player to display things

such as the elapsed and remaining playback time of a track.

Writable CDs

CD-Rs (compact disc-recordable) and CD-RWs (compact disc-rewritable)

are increasing finding their way into many radio studios as the technology is

becoming more affordable and easier to use. Some community stations

have CD-Writers, and many are using them to distribute programming. This

is especially important where CR stations share programming.

CD-Rs - writable CDs that can only be written once - can be read by almost

any conventional CD player. CD-RWs - rewritable CDs that can be erased

and reused several times - may not be read by some CD players (though this

is changing rapidly). This is because CD-Rs are often "finalised" when they

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Caring for CDs

The CD is a very delicate system, using the deflections of light off

microscopic bumps to read audio. The CD is coded with a variety

of error-correcting techniques to make it more reliable, but unless

you look after your CDs, and handle them properly, they will be

damaged and start "skipping" or not play at all. Being an optical

based system, the usual problem is scratches and chips on the

clear polycarbonate layer which prevent the laser from reading

the data properly.

zTo take a disc from its case, press down on the centre of the

case and lift the disc out, holding it carefully by the edges.

zFingermarks and dust should be carefully wiped off the disc's

recorded surface (the silvered side) with a soft cloth. CDs do

not have any grooves that can collect dirt and dust, so gently

wiping the disc with a soft cloth should remove most dirt. To

clean the disc, wipe in a straight line from the centre to the

edge. Wiping in a circular motion will scratch a large part of

the spiral data track and will cause the disc to "skip".

zNever use chemicals such as record sprays, anti-static sprays,

benzene, methylated spirits or thinners to clean CD's. Such

chemicals can do irreparable damage to the disc's plastic

surface.

zReturn discs to their cases after playing to avoid scratches that

could cause the disc to "skip".

zDo not bend the disc.

zDo not leave the discs in the sun, or in areas of high temperature

or humidity. Long periods in high temperatures can cause the

disc to warp.

zDo not stick labels on the label side of the CD. If you need to

write on the label side of the CD, write very gently with a

permanent felt-tipped or other soft-tipped marker. Do not use a

hard-tipped pencil or ballpoint pen. Never mark or write on

the recorded side of the disc.

are written - that is, a Table of Contents is written into the sub-code

when it is written. It may be worth investigating if your choice of CD

player can play "unfinalised" CD-Rs, as this feature may become more

useful in the future.

For more on writing CDs, see Section B: CD Writers on Page 145

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COMPACT DISC PLAYERS

A Compact Disc player is used to play CDs. The machine consists of a very

sensitive reading mechanism that reads digital information from a CD. The

CD player also contains digital-to-analog conversion circuits. These digital-

to-analog conversion circuits convert the digital data stored on the CD into

an analog audio signal that can be fed into a mixer or amplified for a

loudspeaker.

For many community radio stations, CDs are the main source of audio other

than the microphone. As a result, there is an enormous demand on the

broadcast CD player. These machines are often in continuous use for up to

18 hours a day, and are opened and closed thousands of times each month.

A radio station environment demands ruggedness, reliability, and instant

cueing from audio source equipment. This is why studio CD players are

built differently, and have controls and other features that are different to

those found on a domestic CD player. However, if you are familiar with

domestic CD players, then a few minutes with the manual of a broadcast CD

player will teach you all of the extra features.

For more on compact discs, see Section B: Compact Discs on Page 138

Playing CDs in a player

The basic operation of a CD player is straightforward. It involves putting a

CD in the machine, choosing the track you want to play, and then pressing

the play button to start playback. The CD is usually placed in a tray that

slides out of the body of the player. In some players there may be a slot for

the CD instead of a tray. Consult the user manual for your particular CD

player for specific instructions on its features and operation.

An open/close button opens the CD player's disc tray. Press it to open the

tray and insert the CD.

Always place the CD in the disc tray with the label facing upwards. CDs can

only be played on one side, and putting a CD in the wrong way round will

cause the CD player to "freeze up" as it tries to read the CD. It will eventually

give up trying, and you will be able to open the tray and take out the CD, but

this wastes precious time. When the CD is in the tray correctly, press the

open/close button again to close the tray.

Many broadcast CD players disable the open/close button if a CD is playing

in the machine. This stops presenters from accidentally ejecting the

wrong CD.

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Choosing and playing tracks

Choosing tracks on the CD involves pressing the TRACK or SEARCH buttons.

Some CD players use a jog wheel instead of a button to select tracks. A jog

wheel is a control that is turned instead of pushed like a button. Turning it

clockwise (to the right) will increase the track number. Turning it anti-

clockwise (to the left) will decrease the track number.

Once you've selected a track, press the PLAY button to play that track. One

of the marks of a good quality broadcast CD player is that when you press

play, the machine starts playback instantly. There is no delay. These CD

players "cue" the track when it is selected. This means the tracking mechanism

in the machine immediately reads the sub-code on the disc and positions

the read laser at the start of the track that is to be played ready for playback.

These players often have a CUE button instead of a pause button, or an

AUTO CUE control. This control flashes for the short time it takes the player

to find the track. It then stays lit once the track is cued.

Some CD players may take a few seconds to start playback and do not start

instantly once you've pressed PLAY. This short amount of time is taken by the

CD player to look for the track you've chosen. To minimise the "dead air"

created while the player locates the track, you can cue the player as follows:

Use the track controls to select the track you want, and then press PAUSE.

Make sure the pause indicator is showing, or that the elapsed time is

shown as zero.

When you are ready, press PLAY - and the track will play instantly.

Controlling CD players from an on-air mixer

Broadcast CD Players often use fader start, allowing them to be controlled

from the studio mixing desk. In this case, the start button or the on-off buttons

on the mixing desk can be used to play and pause the CD player. The

mixing desk and the CD player have to be capable of using this feature if you

want to use fader start.

Elapsed time and remaining time

The term elapsed time means the amount of time that has passed since the

beginning of the track that is playing. The term remaining time means the

amount of time left before the track comes to an end. Normally, the CD

Do not EVER push the tray closed, as this will damage the motor

that opens the tray. Damaging the motor may cause the player

to refuse to open or close at all. Avoid using special shaped CDs

(heart shaped CDs, octagonal CDs etc.). Trying to play them

may damage your CD player.

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player's display shows elapsed time. That is, it counts up the seconds and

minutes that have passed from the time the track started playing. A CD

player used in a broadcast studio should also be able to display the remaining

time, or the time left before the end of the track. This is an essential feature as

it allows presenters to see how much time is left on a track, so that they can

prepare the next item. Presenters don't want to be surprised when the track

comes to an end. They must be prepared for the end of the track so that there

is no dead air time while they set up the next item. You can choose whether

elapsed time or remaining time is shown on the CD player's display by

pressing a button marked TIME or DISPLAY.

One track at a time

Another important feature of broadcast CD players is that they should be

able to play tracks one at time. Domestic players play tracks continuously

from the beginning of the CD to the end. It is very rare that a station will play

an entire CD from beginning to end. Normally stations play only one track

from a CD and then an item from a different source - another CD player, or

the MD, or a microphone. It makes your job much easier if you don't have

to worry about stopping the CD player while starting the next item. This is

why it is important that the CD player is capable of playing one track and

then pausing itself. A button labelled SINGLE/CONT, or the AUTO CUE

control, normally controls this. Pressing this button will put the player in

single play mode - that is, it will play one track and then pause. Pressing the

same button again make the machine continue with the next track. The play

mode will be shown on the display.

Other functions

A LOOP function allows a part of a track to be looped - that is to be played

over and over. The REPEAT function allows a track, or the whole CD, to be

played repeatedly. A PROGRAMME PLAY function allows the running order

of tracks on a CD to be programmed.

After the mixer and the microphones, the CD player is possibly the most

important item in a community radio studio. So it is important to choose the

right CD players for your station.

As we've said, your CD players need to be rugged and reliable. They must

be chosen for their ability to play even dirty or scratched CDs. There are

dramatic differences between CD players. There are many factors that are

not easy to judge without experience. The experience of fellow broadcasters

is valuable here. Ask around before buying CD players and see what other

stations have to say.

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Cleaning and maintaining CD players

Maintaining the CD player involves keeping the unit clean both

externally and internally.

The lens used to focus the laser beam that reads the CD and the

optical sensor that picks up the reflections off the CD can gather

dirt and dust. Using a Cleaning CD approved by the player's

manufacturer once a month should prevent this from becoming

a problem.

Also, keeping the CD tray closed and your CDs clean (no sticky

fingerprints and dust) will help prevent dirt getting into the

machine.

Connectors and connections for the player

Typically, broadcast CD players have two stereo outputs, one balanced and

one unbalanced. These usually use male XLR connectors for the balanced

output, and RCA connectors for the unbalanced output. (Note that consumer

grade CD players are often used in CR stations, and tend to have only the

RCA outputs.) For RCA connectors, the left and right channels are usually

colour coded, with red indicating right and white indicating left.

Most professional CD players also have digital outputs. These may be marked

OPTICAL or S/PDIF (Sony-Philips Digital Interconnect Format). Using these

outputs, the CD player feeds the digital information from the CD directly to

a digital mixer or the digital input of a digital recording device, such as a

computer, minidisc or DAT recorder. This avoids any loss of quality that

may result from D/A conversion. Optical ouputs need a special optical

cable.

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COMPACT DISC WRITERS (CD WRITERS)

Today, writable CD drives (CD-Writers or CD-Burners) are standard

equipment in most new computers. A CD-Writer allows you to take audio or

data files from your computer and place them on CD. CDs containing audio

can be played in a CD player, or if the CDs contain data, they can be used in

a computer.

CD-Writers are relatively inexpensive, as are the blank CDs they use.

CDs have rapidly begun to replace cassette tapes and floppy discs as the

medium of choice for storing recordings and data.

Pre-recorded CDs are mass-produced through a complicated manufacturing

process which is not practical to use unless producing hundreds, thousands

or millions of CD copies. However as CDs became the standard medium for

audio, the demand for a simple CD recording technique grew. At the same

time, computer users needed a medium that could store more data than

floppy discs. In response to this demand, electronics manufacturers

introduced the CD-R and the CD-Writer.

For more on compact discs, see Section B: Compact Discs on Page 138

CD-Rs

CD-R stands for CD-ROM Recordable. A new CD-R does not have

microscopic 'bumps' on its surface. That is, it contains no digital data. The

CD-R is coated with a special chemical film coated with a light sensitive dye

into which the 'bumps' can be burned using a CD Writer. When the disc is

blank, the dye is translucent and light can shine through it and reflect off the

metal surface. But when the dye layer is heated, it darkens so that light can't

pass through it.

By darkening particular points along the CD track, and leaving other areas of

dye translucent, you can create a digital pattern that a standard CD player

can read. The light from the player's laser beam will only bounce back to the

sensor when the dye is left translucent, in the same way that it will only

bounce back from the flat areas of a conventional CD.

A CD-Writer is used to burn this digital pattern onto a blank CD-R. A CD

Writer has two lasers: a standard read laser (like a normal CD player), and a

write laser. The write laser is more powerful than the read laser and is

intense enough to darken the dye material on the CD-R. The weaker read

laser does not affect the dye. This means that information on the disc will not

be affected by the read laser.

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Advantages & Disadvantages of CD-Rs

The main advantage of CD-R discs is that they work in almost all CD players

and computer CD-ROM drives. CD-Rs are also the cheapest media available.

They are even cheaper than most high-quality cassette tapes.

The only drawback of CD-R is that once you've burned in the digital pattern,

it can't be erased or re-written. It is possible to leave out some areas on the

disc for later writing, but this creates a multi-session CD. A multi-session CD

can not be read properly in a standard CD Player and some older

CD-ROM drives.

CD-RW

To overcome the problem that the CD-R cannot be erased or rewritten, a

new format was introduced in the mid-90s, called CD-RW (or CD-ROM

Rewritable). The laser of a CD-RW writer, called a CD-Rewriter, can both

burn bumps into the media and also melt the media back into its original

state. In place of the dye layer in the CD-R, a CD-RW disc contains a chemical

compound that can change its form when heated to certain temperatures.

When the compound is heated above its melting temperature, to around

600 degrees Celsius, it becomes a liquid. At around 200 degrees Celsius, it

turns into a solid.

The solid form of the compound is translucent (light can show through it),

while the liquid is dark. On a new, blank CD-RW disc, all of the material in

the writable area is in the solid form, so light will shine through this layer to

the reflective metal above and bounce back to the light sensor. To write

information on the disc, the CD-Burner uses its write laser, which is powerful

enough to heat the compound to its melting temperature. As with CD-Rs,

the weaker read laser does not change the state of the material in the

recording layer.

Advantages & Disadvantages of CD-RWs

Due to the very flexibility of the medium, CD-RW discs do not reflect as

much light as the other CD formats and cannot be read by many older CD

players and drives. So these are not a good choice for music CDs. However,

most new drives and players, including all CD-Rewriters, can work with all

the different CD formats. For the most part, they are used to back-up

computer files.

CD-Rewriters can write to both CD-R and CD-RW discs, whereas CD-R drives

can't write to CD-RW discs. CD-RW discs are, however, about twice the

price of CD-Rs. CD-Rs and CD-RWs are written using light and for this reason

should be kept away from strong direct light, as this can corrupt the

information stored on the disc.

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Read & write speed

CD-Writers can read and create CDs at different speeds: This is usually

expressed as a combination of two figures, a read speed and a write speed.

Both are written as a multiplication factor (1x or 4x or 8x and so on).

At 1x (1 times) writing speed, the CD spins at about the same rate as it does

when the player is reading it. This means it would take you about 60 minutes

to record 60 minutes of music. At 2x speed, it would take you about half an

hour to record 60 minutes, and so on. Current CD-Writers operate at 24x

writing speed or faster. Faster writing speeds need a faster connection between

the computer and the writer; and a blank disc that is designed to record

information at higher speed.

Like the CD writer, the CD-Rewriter also works at different speeds. In fact, the

device is usually specified by its write speed, its rewrite speed and its read

speed. (For example a CD-Rewriter would be specified as 16 x 8 x 32. This

means it can write CDs at 16x speed; it can re-write CDs at 8x speed, and can

read data from a CD at 32x speed.) The speed for re-writing is often slower

than the write speed, as rewriting needs the extra step of first erasing the

existing data on the CD.

Internal or external CD writers?

Most often the CD-Writer or Rewriter is part of a computer, and the information

written to the CD comes from a file stored on the computer. The CD-Writer

can be fitted into the case of the computer (an internal writer) or can be an

external unit that connects to the computer via the USB, Firewire or PC Card

connections.

Internal CD-Writers are relatively easy to install, and are about twice as fast

and half the price of external writers. However external writers do have

some advantages:

Installing an external writer is much easier and you don't have to open

up your computer's case.

External writers are portable. This means that the writer is not tied to a

particular computer and can be connected to any of the computers at

your station. It is also a good solution if you want to use the CD-Writer

with a laptop computer.

External drives are usually compatible with different types of computers.

(Remember, though, that an external writer is likely to be about 50% more

expensive than an internal one; so you should factor that in when making

your choice.)

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CD burning software

Using a CD-Writer attached to your computer requires CD writing software.

Basic CD writing software will be supplied with the CD-Writer. The software

allows you to decide what type of CD to make (audio or data) and choose

the files you want to write to the CD. Programmes such as Nero Burning

Rom, Adaptec Easy CD Creator and Toast (for Apple Macintosh computers)

are very popular. In many cases, the software is supplied along with the

writer device itself - but these versions may be limited in function.

Writing a CD places large demands on your computer and things can go

wrong. Do not be surprised if some of the CDs you are burning don't come

out right. CD-Rs cannot be overwritten. This means that when an error

occurs while writing the disc, you have to throw away the whole disc. If you

continually have problems burning CDs, try to reduce the write speed. The

most common problem when writing CDs is called a buffer underrun. This

happens when the computer is unable to send data to the CD-Writer fast

enough. Reduction of the write speed can overcome this problem.

Not all CD-Writers are part of a computer. There are a number of stand-

alone CD recorders available for both domestic and professional use. Often,

these have two drives that allow you to record music tracks directly from

one CD to another.

Remember that copying pre-recorded CDs raises very serious

that could cost you a lot of money.

These stand-alone recorders can also have audio inputs, allowing them to

record incoming signals, much like a cassette or minidisc recorder. These

writers are usually fast and accurate, but typically can only be used to create

music CDs. Professional models are also very expensive when compared to

computer-based writers.

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COMPRESSOR/LIMITERS

A compressor limiter (compressor) is a device used in most community

radio station transmission systems. It is used to process the signal that comes

from the broadcast studio before it is transmitted. The compressor/limiter

keeps the level of your station's signal constant and at the best possible

volume, both for your listeners and to compete with other stations.

In broadcast terms, we say the compressor is used to control the dynamic

range of the station's sound. Dynamic range is the range between the loudest

and quietest sounds that are broadcast. Reducing the dynamic range of the

signal by using a compressor is called compression. The effect of

compression is to make your station sound louder and clearer on air.

The limiter, on the other hand, sharply controls the audio output level at a

predetermined level. This is often a much more harsh adjustment to the

sound, and must be used with caution, as it can make your audio sound

very bad if done improperly.

More usually, we use devices that combine both functions, allowing you to

compress the signal to a certain extent, and limit it sharply after a certain

point. Such devices are called compressor/limiters.

Not all compressors work exactly as shown above. For example, some

compressors monitor both the input and the output audio. Also, there is

computer software to carry out the role of the compressor. However the

underlying principle remains the same.

The compressor control panel generally has two meters:

one meter indicates the amount of gain reduction or compression

the other meter usually shows the signal level of the compressor's audio output.

The threshold control is used to set the signal level at which you want the

compressor to begin reducing the level of the signal. The ratio control

Fig 8 : A schematic view of how a compressor/limiter functions

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controls the change of output level for a given change in input. (For example

a compression ratio of 2:1 means that for a 2dB (dB = decibel) increase in

input signal level, the output signal will only increase by 1dB.)

The speed at which the gain is reduced in response to an increase in input

signal level is called the attack time. This is usually specified in milliseconds,

and is set using the attack control.

The speed at which the gain is restored to its original level after the input is

removed is called the release time. This is set using the release control.

You need to listen to your signal very carefully in order to set these parameters.

If the attack time is set too fast, the compressor will respond to even the

shortest peaks (loudest sounds), causing the level to change very quickly.

For example, the beats in a dance track often cause short peaks in the signal.

If the attack time of the compressor is so short that it responds to the individual

beats, the compressor will reduce the signal level on each beat, and produce

a very unnatural sound. On the other hand if the attack time is too slow, the

compressor's output may exceed the desired maximum before the

compressor acts on the signal.

Too fast a release time causes "breathing" as the gain changes rapidly. If the release

time is too short, quiet sections of music will be lost as the compressor will still be

reducing the gain, even though the loud input signal is no longer there.

Many compressors have an auto (automatic) switch for the attack and release

time. When the auto switch is on, the attack and release times are set

dynamically, based on the input. This is often the best for CR stations, as the

system is self adjusting to the needs of different kinds of audio and

programming.

Some compressor/limiter units have an additional gain knob that can be

used to match the final output gain to any of a variety of equipment. The

output level resulting from using the gain control can be monitored on the

output level meter.

Some compressors also have a stereo link button, which links the two channels

of the compressor together so that both channels process their signals in the

same way. If your compressor doesn't have a stereo link button, you will have

to set controls for each channel to exactly the same level.

Pressing the bypass button bypasses the compression circuitry, and allows

you to quickly compare the compressed and uncompressed output.

The compressor has a variety of possible settings. Small adjustments to

any of them can make a considerable difference to your station's on-air

sound. It is a good idea to document the compressor settings that work

best for your station and compressor. Keep this record available for

reference. Also, once the compressor has been set for your station, put

a guard or protective covering on the front panel to prevent anyone

from accidentally changing the settings.

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The compressor settings you choose will depend very much

on your preferred sound. However, many stations have been

happy using:

za threshold level of 0 dB

zcompression ratio of between 1.5:1 and 4:1

Set the output gain so that the output level meter reads the ideal

input signal level for subsequent equipment (often 0 dB).

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COMPUTER HARDWARE

Computers have become a vital tool in modern communication, both for

office work and for the production of high quality audio and video with a

considerable decrease in effort. Computers and digital technology have

developed hand in hand over the last few decades, as digital storage was

initially a system conceived for computer data.

There are two vital components to any computing system:

The hardware. This is the wiring, electronic circuits, disc drives, monitors,

keyboards and so on that make up the physical machine we call a

computer.

The software. This is the term used to describe the programmes that we

use on the computer.

Hardware and software must work together if we are to get anything useful

done with a computer.

For more on computer software, see Section B: Computer Software

(for Radio) on Page 159

Your choice of computer hardware will differ according to your needs and

according to the kind of software you are planning to use on your computer.

In general, however, all computers share certain basic hardware:

Fig 9: A schematic view of the average computer's innards.

The CPU tower or cabinet

All computers need a case to house all the electronic components. Cases

can come in a variety of colours and shapes, but all of them have the same

purpose - that is, to hold and protect the electronic components. Modern

CPU towers are usually of the ATX or Micro-ATX variety, which means they

automatically switch the power off when the computer is shut down. It is a

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good idea to assess how large a case you need based on the number of

peripheral systems (CD-ROM drives, CD-writers etc.) that you plan to install

internally - these are usually accessed through configurable slots in the front

of the system, and smaller cabinets have fewer slots.

The computer's power supply is normally supplied with the case. This power

supply, called an SMPS (Switched Mode Power Supply), is basically an AC

to DC convertor; and can come in a variety of ratings: 200 Watt, 300 Watt

and 450 Watt are most common.

Plan ahead and get a more powerful SMPS than you need if you

intend to add more components later on to the system. (But remember

that it will still consume its rated power whether you actually install

those components or not!)

The SMPS usually has a fan fitted on it which is visible at the back of the

cabinet: This is because the power conversion process generates a lot of

heat which needs to be vented.

Motherboard

The motherboard is a large circuit board into which all the other components

are plugged: The motherboard supplies power to all the components and

connects them together, transporting data from one component to the other.

The motherboard is mounted in the computer's case, and has slots and

connectors for the other components

Motherboards vary in terms of speed and features. More expensive boards

tend to be faster, more reliable and support more features and advanced

components. It is important to match a motherboard to the processor unit

that you install, as many of the features can be interdependent: A fast processor

can be hampered by a poor motherboard, or a fast motherboard can be

underused by a slow processor.

Processor and peripheral manufacturers usually specify the best

motherboard solutions for their equipment, so it's always worth having

a look at those while deciding your configuration.

Last but not least, it is always worth considering how futureproof your

motherboard is in terms of plugging newer peripherals into it: You may like

to increase the RAM or plug a different card into one of the slots later on, and

you should explore whether this will be possible at a later date.

The Central Processing Unit (CPU)

The CPU can be thought of as the brain of the computer. It is the part of the

computer that does the actual computing, and co-ordinates the actions of

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the whole system. Software programs are written to give the CPU a set of

instructions. The CPU will follow the instructions to accomplish a specific

task. The two principal CPU manufacturers globally are Intel Corporation

and Advanced Micro Devices (AMD).

Like all other components, the CPU is connected to the motherboard. It is

easy to spot on the motherboard, as it usually the largest microchip on the

board. This is why it is often called the chip for short. The CPU is covered by

a cooling fan, as modern CPUs are very powerful and compact, and generate

a lot of heat.

Computers are often differentiated by the type and speed of their CPU. For

example, in terms of type, people may refer to a computer as a Pentium III

or Pentium IV or as an AMD Dual Core Turion.: This means that the

computer has a Intel Pentium III or IV series processor or an AMD Dual Core

Turion processor installed.

The processor name also usually has a number and a frequency attached -

like Pentium IV 2.4 GHz, for instance. The 2.4 GHz refers to the speed of the

CPU and indicates that it can operate at a speed of 2.4 GHz (or 2400 MHz).

This means it is actually capable of doing 2400 million operations per

second, which should indicate just how fast modern computers are.

The newest type of processors actually carry two processor chips in one

casing - 4 and 8 chip versions are also beginning to make an appearance,

but are still very expensive. These types of processors are called Dual Core

processors, and are quickly becoming the modern standard for computer

CPUs.

Random Access Memory (RAM)

The CPU has to process digital data to carry out instructions. This data has

to be stored so that the CPU can quickly retrieve the data, process it and

save it again for further processing. This storage space used to hold the

data that the computer is working with at any time is referred to as the

computer's memory. Memory is like the CPU's scrap paper - somewhere

to write down notes and calculations as it works. It is referred to as Random

Access Memory (RAM). RAM is storage space that is available for short-

term storage of data.

RAM relies on a constant presence of electrical charges, and operates

only when the computer is turned on. Data written to RAM vanishes

when the system is powered off.

Computers are also differentiated by the amount of RAM they contain. The

more RAM in the computer, the faster it works, but this is only applicable up

to a point: For a slow processor or motherboard, increasing the RAM cannot

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push performance beyond a point. Most computers currently should come

equipped with at least 512 Megabytes (512 million bytes of data) of RAM,

though increasingly, advanced software has meant more should be preferred

if it is possible. Computers can often take upto 4 Gigabytes of RAM in all,

though this is dependent on the motherboard.

The computer has another kind of storage called Read Only Memory (ROM).

ROM contains data that is permanently etched onto a chip, and typically

stores the commands necessary for a computer to boot up, or start.

Secondary storage devices: Hard disks (HDDs). Floppies and CD

In addition to RAM and ROM, computers have secondary storage devices

such as floppy discs, hard drives, and CD-ROMs. These devices are

responsible for long-term storage of data and software programmes. They

can hold much more data than RAM and ROM, and are much less expensive.

They are also much slower than the primary storage devices. Data stored in

memory can be accessed by the CPU in nanoseconds (a nanosecond is a

billionth of a second), while data on a hard drive is accessible in microseconds

(a thousandth of a second). This means your hard drive is about a thousand

times slower than RAM.

Most modern computers have hard discs capable of storing 120 gigabytes

or more of data, with 250 and 500 GB becoming rapidly more common.

(A gigabyte or GB equals a thousand megabytes.)

Floppy disc drives use an external storage medium called a floppy disc,

which is a small 3.5" square plastic case that contains a magnetic surface.

Though comparatively less used nowadays, they are still found on many

older systems, especially in small towns and more remote areas.

The graphics/video card and the monitor

The video card and monitor allow us to communicate with the computer by

seeing what it is actually doing to the data we are giving it. We need to give

the computer instructions and data before it can do anything. We then need

to see the results of the instructions displayed in a way that we can understand.

The monitor, or screen, works much like a television screen. Like a television,

the computer monitor needs a video signal to display a picture. The video

card creates this signal by interpreting the data the computer processes. The

video card connects to the motherboard and converts the computer's digital

output into text or pictures for display on the computer monitor.

Demanding video applications like video editing may require

specialized video cards that carry their own memory and execute

this process quickly.

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Monitors come in several varieties: Cathode Ray Tube (or CRT) monitors are

most common - and cheaper - and work exactly the way your TV does. They

come in flat screen and normal screen varieties, with flat screen to be

preferred because the picture doesn't distort as much at the edges. The

other type of monitor is the LCD or Liquid Crystal Display, which are thinner

and lighter, but are somewhat poorer in colour rendition.

Monitors are usually 15" or 17" in diagonal screen size - the latter consumes

more power - but larger monitors (21", 25") are also available for specific

purposes.

Keyboard & Mouse

The keyboard and the mouse provide us with a way to input data into the

computer, and interact with it. By typing on the keyboard - which is almost

exactly like a typewriter keyboard - and pointing and clicking with a mouse,

we are able to give instructions to the computer. The instructions are

converted to digital data.

Keyboards are usually in English, though specific language keyboards are

also available. In many cases, the same keyboard is adapted to type letters of

various other languages, a function that is guided by the availability of the

font (or typeface file) for that language on the computer.

Mice are available in two button and three button versions, with various

functions being accessed by each of the two or three buttons - most functions

can be achieved with two. Many modern mice also carry scroll wheels, a

small wheel on top which you can use to quickly move up and down on a

page displayed on the screen. Older mice have a trackball based design

where a small rubber ball at the bottom moves as you move the mouse.

Newer mice have an optical input system where a laser reads the surface

the mouse is moving on to understand which direction it is moving in (and

are hence known as optical mice.)

Sound or Audio cards

Adding a sound card to a computer makes it possible for the computer to

play and record sound.

The card converts audio signals into a digital format that can be processed

by the computer. The card also converts digital audio stored on a computer

into a format that can be sent to other equipment such as loudspeakers and

the mixing desk.

Sound cards vary enormously in quality and features. In the radio studio the

primary purpose of a computer is to play and manipulate sound. Therefore,

there are more demands on the studio sound card than on a standard office

or home computer. The right choice of sound card used in a studio computer

is vital. As the studio sound card tends to be more sophisticated than others,

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it is also often more expensive. Even basic sound cards today give very good

quality audio; but if you intend to connect professional grade microphones

directly to the computer, a sound card that has balanced and unbalanced

connectors - on the card itself or on an attached break out box - may be a

good choice.

For more on balanced and unbalanced connectors, see Section B: Balanced

and Unbalanced Connections on Page 131

Modems and LAN cards

Computer communications are becoming a part of everyday life. More and

more people are using the internet and e-mail as a resource and as a means

of communication. By connecting our computer to a phone line or a network

connection, we are able to communicate with other computer users.

A modem makes it possible for a computer to communicate through phone

lines. Modem is an acronym for Modulator/Demodulator. Modems translate

digital computer information into analog signals used over phone lines.

They can also work in reverse and translate the analog signal from a phone

line into a digital signal used by a computer.

Modems are distinguished by the number of bits per second (Bps) of

information that they can transmit. Nowadays, commonly used modems

operate at 33 600 and 56 000 bits per second. However, older modems that

work at lower speeds are still used in some places.

Like CD-writers, modems can also be internal or external, though it is more

usual to find the internal ones today. They need to be connected to the

telephone socket using a telephone cord, more usually known as an

RJ-11 connector.

For more on RJ-11 conenctors, see Section B: Connectors (Audio & Telecom)

on Page 166

If you have more than one computer in your station, you will probably want

to share files and resources such as printers amongst them. To achieve this

your computer needs networking hardware. This hardware is a network

interface card (NIC), often just called a network card or Large Area Network

(LAN) card. Most new computers are supplied with a network card. The

network card allows the computer to talk with other computers on the network

(that is transmit and receive data).

Modems and network cards are more important for the office systems

than for any computers based DAWs that you may be installing:

Most of the outputs from a DAW are likely to be through the mixer or

on a CD, so networking the system is not a priority.

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If you have more than two computers that you want to connect together,

you may need a network hub to which you connect all of your computers.

The hub switches information between the computers.

Other peripheral hardware

In addition to the hardware already listed, there is a wide variety of external

hardware, often referred to as peripheral devices (or peripherals) that can be

connected to a computer. The more common devices are CD-Writers used

to make audio and data CDs; printers for printing information onto paper,

and scanners to convert text or pictures on paper into a digital format for the

computer. Many stations today use CD-Writers and store and distribute

programmes they have produced.

It is also useful to have a printer for printing out text reports, letters and other

information. Printers can be colour or black and white; and can be inkjet or

bubblejet printers; or laser printers. Laser printers tend to be more expensive,

but their toner (ink) cartridges tend to last a long time. Inkjet printers are

intended for lighter work. They may cost less initially, but often have

expensive ink cartridges that over time can cost more than the printer itself.

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COMPUTER SOFTWARE (FOR RADIO)

As we saw in the hardware section, there are two parts to any computer

system: The hardware, and the software. Software is the term used to describe

the programmes (or sections of computer code) that we use on the computer.

The programme is a set of instructions that instructs the computer in how to

execute a given task: This could be typing a word on the screen, or

manipulating audio or anything that that you want the computer to do. Both

hardware and software are very important, and we need the right hardware

and software if we want to get anything useful done with a computer.

Different software for different uses

There are different software programmes or packages that perform different

functions. For example to type and edit a script, or a letter, you need a word

processing programme such as Microsoft Word or Open Office Writer.

For accounts, budgets and spreadsheets, there is a wide variety of software

you can use to make accounting easier, like Microsoft Excel, or OpenOffice

Calc. Graphic designers use software packages for design and layout, like

Adobe InDesign, or CoreDraw! or OpenOffice Draw. We also use internet

browsing software such as Mozilla Firefox or Internet Explorer for accessing

the Internet; and e-mail software such as Outlook Express or Mozilla

Thunderbird for sending and receiving e-mail.

Proprietary, Freeware, Shareware and Open Source

Software can be proprietary (meaning it has to be purchased before use);

freeware (meaning it is free to access and install); or shareware (where you

can install it, but should pay for it if you continue to use it beyond a fixed

amount of time). When software is purchased, you are basically licensing a

copy of the software for use; and this license may limit the number of

computers you can install the software on.

Over the last several years there has also been a worldwide movement to

create and use software where anyone can access the basic code and make

changes to suit their own purposes. This is called the Open Source movement,

and it has resulted in a large variety of freely available and customizable

software that perform nearly all the functions that proprietary software was

once invariably required for - including audio editing and manipulation.

Many open source software packages today are available for download

directly from the Internet - but be careful while doing this, because people

pirate or make illegal copies of proprietary software as well. This is not only

illegal, it is unfair to all those who make a living by writing the software.

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To go into all the kinds of software used on computers for various tasks is more

than can be covered in this manual. So we'll focus first on the important software

that we may use on a computer used for radio and audio related work.

1. Operating Systems (OSs)

The operating system controls all of the computer's hardware and provides a

base upon which other software can be used. The operating system manages

the hardware for the user, and provides onscreen images that you can

understand when you are working on the computer. On PC based computers,

the popular OSs are Microsoft Windows (Windows XP SP2 is common, with

Windows Vista now preinstalled on many computers), as well as many variants

of the GNU/Linux open source OS (including variants like Red Hat, Fedora

and Ubuntu, some of which must be paid for). On Apple Macintosh

computers, often used for professional audio and video work, the current OS

used is Apple OS 10.5, also popularly known as Tiger.

Many computers still use older variants of Windows, such as Windows 95,

Windows 98 or Windows 2000 or ME. It's usually a good idea to get as new

an edition of the OS you select as possible, as it will have updated controls

and software for the hardware that you install on the system.

Some OSs are written specifically to facilitate multimedia and audio work on

a computer. One such freely downloadable OS is Ubuntu Linux Studio,

which comes bundled with audio processing and editing applications that

work seamlessly in tandem with each other.

2. Audio editing and processing software

Audio editing and processing software is used to record, input, adjust, trim

and refine audio from a variety of sources to make a programme. In the radio

production studio, software programmes such as ProTools, Cakewalk Pro,

Peak, Nuendo, and Audition are the common proprietary software choices.

The open source preferred choice is usually SourceForge's Audacity. Other

possible choices are Solition II, Audioblast and Reaper.

A screen capture of Nero Wave Editor, a simple audio

editing software bundled with the Nero Ultra

CD burning tools package.

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These programmes let us mix and edit sounds, add sound effects, and

generate digital audio files that can be sent to another computer for playout

in the studio, or for writing onto a CD-R. Advanced audio editing programmes

often demand more advanced sound hardware, and the soundcards used

in audio production computers are usually more sophisticated than those

on a standard computer. But CR stations often have less demanding

requirements than professional studios, which require very high grade

adjustments to music recordings for film and CD production. So simpler

software and hardware can often be used, without the tremendous variety of

functions that are often available in pro software.

As audio editing is usually graphical based - the software displays pictures

of the sound waves you are working with - this often makes it easier to work

with the sound, as opposed to the laborious manual work one had to do in

studios once upon a time. Software can emulate most of the expensive

hardware that audio studios once used to be equipped with, because the

software can now manipulate the audio in exactly the same way - an important

consideration in making radio more accessible to communities.

Most audio editing softwares also let you save the final version of the audio

in a variety of audio file formats: MP3, WAV, AIFF, and so on.

3. Playout software

Stations that use computers in the broadcast studio will use playout software.

Playout software provides a way for presenters to quickly access audio files

stored on the computer and then to play them on the air. Programmes such

as Netia, On the Air, Wavecart, Radiohost and many others have been

especially designed for use in the radio studio.

There are free and open source counterparts like ZaraRadio that can be

used for playout as well; and many small radio stations use simple audio

player software like WinAmp to queue audio for playing.

Using playout software may require more sophisticated sound and

computer hardware, as well as considerably higher expense.

4. CD burning software

As noted in the section on CD writers, there are specialized softwares that

can help you with the process of organizing and burning your files onto

CDs for archiving or for playout. These include versions of Nero Burning

ROM, Alcohol, Toast (for Macintosh), or CD Burner XP. Most will give you

advanced functionality like leaving the disc unfinalized, or making a CD-R

multisession.

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5. Audio playback software

Most Windows OS based computers come equipped with a version of

Windows Media Player, a playback software which you can use to play

audio. But a variety of software is available to play audio on a computer:

These range from WinAmp and Realplayer to Quicktime Player and

Jet Audio.

Your choice of software depends on the scale you want to work at, how

much you want to automate the process - and what kind of a budget you

have. There may be differences in functionality between many of these

softwares - but then again, you may not need much of the pro functionality

or controls to achieve many of the things you require as a CR station.

Your choice of software depends on the scale you want to work at,

how much you want to automate the process - and what kind of a

budget you have. There may be differences in functionality between

many of these softwares - but then again, you may not need much of

the pro functionality or controls to achieve many of the things you

require as a CR station.

Don't invest blindly in expensive software without exploring

availability, support, usability, and functionality.

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Socket and plug fittings vary from country to country, as do the

operating voltages of equipment. As most equipment used in a radio

station is manufactured outside India, it is vital to check whether the

plug supplied with the equipment will fit into sockets here: If it doesn’t,

it may be necessary to obtain adapter plugs that allow us to connect

it to Indian standard sockets. If the operating voltage is also different –

equipment from the United States operates at 110 Volts instead of

220 Volts, for example – then a power adapter may also be required

to step down the voltage.

CONNECTORS (POWER)

While all radio equipment runs on electricity – DC or AC – the cables that

connect all these varieties of equipment to their power sources are often

different from each other – and so are the connectors at each end of the

power cable. In most cases, the connectors will be of one of the following

two types :

1. The standard power plug

The standard plug is the most common power connector, and is usually used

to plug into AC mains supply sockets. AC mains power is of a very high voltage

– 220 Volts in India – and can damage your equipment and cause fatal electric

shocks if care is not paid to the way the plug is wired and plugged in.

Power plugs of this type come in two varieties: A larger variety with thicker

cylindrical pins for heavier loads (often called a power plug or 15 Amp

plug), and a smaller variety with thinner cylindrical pins (often called 5 Amp

plugs) for lighter loads. Each of them requires a corresponding socket, as the

pin spacing is different in each case – but modern socket fittings generally

feature sockets which accept both varieties of plugs.

Plugs need to be wired as per existing international and domestic conventions

for electrical wiring. This is done according to a colour coding system that

identifies the correct wires to be connected to the phase, neutral and earth

points of the socket.

The black wire connects to the pin on the left as seen from the back of

the plug. This pin is most often labelled Neutral, Black or just N.

The red wire connects to the pin on the right as seen from the back of the

plug. This pin is often labelled Live, Red, L or Phase.

The green earth wire connects to the top pin of the plug. The earth pin

is often labelled Earth or marked with the earth symbol.

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Fig 10: Standard wiring for a 3 pin plug in India.

Not all pieces of equipment use the earth wire, and you will have to

read the wiring instructions to see whether or not ‘earthing’ is needed.

Where there is a choice, always try to use a 3 pin plug instead of a

two pin plug for the earth protection the third pin gives you.

Wiring a power plug correctly

Though it appears very simple – and it actually is, once you learn how

to do it properly – there are some basic procedures that must be followed

when wiring a plug.

The first thing is to note that the earth, live and neutral wires of a power

cable each have their own colour coded insulating plastic or rubber

coating. Together they are then surrounded by a second rubber or

plastic coating (mostly white, grey or black) which keeps all three wires

together.

To wire the plug, you will first have to remove a section of this outer

coating, enough to expose the three individual wires, but without

stripping the inner wires’ own coatings. Also, when you do this, make

sure you leave enough of the outer insulation jutting into the plug.

The earth, live and neutral wires are often stuck together. You may have to

separate them by pulling them apart. When you do this, make sure the

insulation (the blue, yellow / green and brown coating) surrounding the

copper wire remains intact. Also, make sure that the three separated sections

are just long enough to fit comfortably into the pins. Depending on the

plug, you may have to leave the green wire a little longer and clip the other

two wires slightly shorter so that they fit comfortably into the pins.

Contd...

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Then remove a very short section of the green, red and black coatings

to expose the copper wire within. Expose just enough so that the

exposed copper portion fits into the holes in the three pins: If you

expose too much, there is a risk that two of the wires may short circuit.

Each of the wires may have several finer strands or filaments of copper

wire. Twist these strands together so that they stay together. Then insert

them into the holes on the pins.

Screw the screws that will hold the copper wire in the pins down firmly,

making sure that they are holding the copper wire down. Tug gently on

the wires once the screws are in to check. If the screws are not firm, or

the pins wobble in their casings, or the screws that seal the plug casing

are loose, change the plug at once.

2. The Kettle plug or IEC connector

The IEC connector is often called a “kettle plug”, as they are often used on

kettles. They are used to supply power to many pieces of studio equipment,

and to computers. The formal name for this type of connector is the IEC320/

C-14 (male) and the IEC320/C-13 (female). The former usually receives the

power, and the latter supplies the power. Commonly, the male connector

will be found on the equipment body, and the female connector will be

found on the end of the cable that is attached to it.

In most cases, equipment that uses IEC plugs and connectors are supplied

with sealed molded plugs that do not have any joints and cannot be rewired

by you. In these cases, if a plug shorts out ot malfunctions, the better option

is to simply purchase the entire connector, with the wire/cable and the

connectors.

A female IEC or kettle plug connector

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CONNECTORS (AUDIO & TELECOM)

There are a variety of connectors that are used to join pieces or groups of

equipment together so that they can communicate with each other, and so

that an audio signal may be passed among them. In some cases, this variety

is the result of efforts by equipment manufacturers to develop proprietary

connectors designed to fit only their own equipment. In other cases, newer

connectors have been developed over time that have begun to coexist with

older connectors.

1. The XLR connector

The three pin XLR connector is probably the most common ‘pro’ connector

that one encounters on broadcast grade audio equipment. Typically, it has

three pins, with Pin 1 used for the shield (or wire mesh) of the armoured

cable, Pin 2 for the phase or ‘hot’ signal, and pin 3 for the cold (or reversed

phase) signal. The three pin arrangement – four and five are also possible,

though less common – make this the connector of choice for balanced

connections.

For more on balanced connections, see Section B: Balanced & Unbalanced

Connections on Page 131

Since the XLR connector design includes a locking tab that clicks into place

when attached - and which must be pressed to release the connector - it is a

particularly safe connector. It is impossible to line the connector up the

wrong way, or misconnect it.

By convention, the male XLR connector – with the pins – carries the signals

out, and the female connector, with the sockets, takes in the signal.

A male and a female XLR connector. Note the tab on top

that must be pressed to disconnect the connector.

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2. ¼" phono plug and jack

The ¼" phono plug comes in two varieties: Two contact or three contact.

The three contact point version, with the two visible black bands, is also

known as the TRS or Tip-Ring-Sleeve connector. The three contact points

can be used for a stereo connection (tip = left, ring = right, sleeve =

ground); or for balanced connections (Tip = hot, ring = cold, sleeve =

shield). The two contact jacks only have a tip and a sleeve; and are used for

mono or unbalanced connections.

3. 1/8" TRS plug or mini-phono plug and jack

The 1/8" phono plug – also known as the mini-phono plug – is the small

cousin of the ¼" connector. On professional equipment, this is found only

on portable equipment – notably field recorders – or on mid-range

soundcards. They are, however, more common on consumer grade and

home audio equipment.

The mini-phono jack is also available in two and three contact versions,

though the latter is much more common. The three contact version is also

the TRS variety (see above) and is most commonly used for unbalanced

stereo connections.

A pair of ¼" phono jacks. Both are mono connectors, as

indicated by the single black band.

A 1/8" mini phono jack. This one is a stereo TRS connector,

as shown by the two black bands near the tip.

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The small size and the (usually) flimsy construction means there are high

failure rates with 1/8" connectors, and that they need constant checking

when used in ‘pro’ work.

4. RCA jack and connector

The name RCA comes from the Recording Corporation of America (RCA)

which was the first to develop this connector for their audio equipment. The

RCA is an unbalanced connector, with the jack having a central pin

surrounded by a flanged edge which acts as the other contact.

Designed for domestic use, it may nevertheless be found on some studio

equipment. The connector is prone to usage related wear and tear, as the

outer ring often spreads due to careless handling and is then unable to make

a clean connection.

5. D-Type connectors

The D-type multi-pin connector is available in male or female versions, and

is often used where large amounts of data needs to be handled.

The connectors range from 15 pin to 50 pin. They are common on digital

equipment and are also often used on studio mixers.

A D-type connector.

A pair of RCA jacks. Together, they make a stereo pair,

with one carrying the L signal and the other the R signal.

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6. BNC connectors

The BNC connector is most often found on RF transmission equipment, and

has a locking ring system that is similar to those found on a lightbulb. The

TNC connector is also quite common, and is a screw type version of the

BNC connector. A third variant, the N-Type connector is a larger version of

the TNC connector. It is able to handle considerably higher RF powers, and

is commonly found on transmission and RF test equipment.

Network, computer and telecom connectors

1. RJ-11 (telephone) connector

The RJ-11 clip connector is used for telephone connections. It is a small

four-pin type connector; and is often found on modem and hybrid units.

The plastic clip snaps into place, and must be pressed to withdraw the

connector from its socket. The connector requires a special crimping tool to

be attached to the telephone cable.

An RJ-11 connector. Note the clip on top which

snaps into place when it is inserted in its socket.

2. RJ-45 network connector

The RJ-45 connector is a larger version of the RJ-11. It has eight pins and is

used for data network cables such as ISDN cables and computer network

cables. Standard computer network cards and network hubs have sockets

for this connector, often known as an Ethernet or LAN (Large Area Network)

connector. This connector needs to be crimped in place within the connector

with a crimping tool as well.

An RJ-45 LAN connector. The 8 wires of the LAN

cable need to be crimped in place.

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3. USB connectors

USB or Universal Serial Bus connectors are found on computers and some

audio devices like MDs and flash recorders. USB devices may be chained to

each other to form a chain as long as 128 devices, all of which can be active

simultaneously. Nowadays, USB is also used to power some devices like

microphones: USB mics are often used on computers.

USB connectors may be classified on the basis of their data transfer standard

(USB 1.0 and USB 2.0) or on the basis of their size (mini-USB and standard

USB). Mini USB is often found on portable digital equipment and digital

cameras. Standard USB is usually found on computers.

USB 1.0 offers data transfers at about 11 MBps (or Megabits per second).

USB 2.0, the newer standard, can transfer at a thumping 480 MBps!

Regular size and mini-USB connectors, both male

A Female USB connector

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A standard (left) and a mini firewire (right) connector

4. Firewire connectors (IEEE 1394)

Originally developed exclusively for high speed digital audio and video

transfer, Firewire or IEEE 1394 standard connectors come in two variants:

Firewire 400 (capable of 400 MBps transfers) and the newer FireWire 800

(capable of a mind-boggling 800 MBps transfer speed.).

This connector comes in a larger and smaller variety as well.

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DECIBELS

When we work with audio equipment, it is important to keep track of the

overall levels of the audio we are working with for two reasons:

1. So that we can compare the relative levels of various sounds and

recordings, in order to adjust them relative to each other; and

2. So that we can keep the audio levels at a level where the equipment’s

circuitry can handle it.

In order to do this, however, it was important to develop a system of sound

units which could mimic the human ear’s way of distinguishing. The units

which were developed became known as the Bel and the deciBel (dB). The

Bel was named after Alexander Graham Bell, the inventor of the telephone.

A deciBel is one tenth of a Bel, and is the more commonly used of the two

measures, as the Bel is a very large unit.

As a measure, the Bel and decibel are logarithmic. Logarithms are an arithmetic

system where large numbers can be expressed as a system of smaller

numbers, and where the progression of numbers is not linear in nature.

(Our hearing is actually logarithmic in nature: A sound that we perceive as

twice as loud is actually nearly four times as loud in absolute pressure terms,

so it is easier to perceive this in relative terms. Additionally, ‘loudness’ is a

very subjective quantity.)

What is important is to grasp that dB always represents a ratio of two

quantities, and not a quantity itself. This can be the ratio of two powers,

voltages, currents or sound intensities. Most often it is a ratio of power

quantities. As we have seen, it is immaterial whether we talk about an audio

signal in terms of the actual pressure wave that we hear or the change in

electrical voltage that a microphone converts it into. Thus, if 0 dB is specified

as some reference value then any number of dB above or below that zero

reference can be used to describe a given quantity.

The standard dB term used for expressing input and output voltage is

dBu. 0 dBu corresponds to a voltage of 0.775 volts. Another dB unit that

is often used is the dBv, which is equivalent to the dBu. An older dB unit

that is used is the dBm. 0 dBm is 1 milliwatt. dBm has no direct relationship

to voltage.

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DIGITAL PLAYOUT SYSTEMS

The advent of computers has not only made the process of editing and

manipulating audio easier, it has also made the process of storing and

accessing large quantities of audio data very convenient. Where radio was

once a purely ‘live’ medium, today we can select and playback a huge

variety of programming with the click of a few buttons.

At its most basic, a digital playout system is a computer set up to playback

audio for broadcast. Most computers are capable of playing back audio

with an appropriately installed sound card and audio playback software.

What distinguishes a digital playout system from other such computers is

the software used to organize, sort and search through the audio stored in its

hard disk – and to ‘queue’ the audio so that it plays back in a specific

sequence and without a pause.

For more on sound cards, see Section B: Computer Hardware on Page 152

For more on audio playback software, see Section B: Computer Software

(for Radio) on Page 159

A large part of using a playout system is creating the sound files the system

uses. For this, the audio must first be stored as digital audio files on the playout

computer. If the original audio is on an analog medium like audio cassette or

LP record, it will first have to be digitized or captured, and then transferred

onto the playout system. On the other hand, if the audio is already on a digital

medium like a CD, it will need to be ripped using a ripping software. Ripping

is essentially a process of converting the audio from its original digital format

to an audio format that is compatible with the playout software.

For more on digitization, see Section B: Analog & Digital Audio on Page 124

All the audio that will be broadcast (‘played out’) from the playout system

has to be in the form of audio files on the playout computer – jingles, ads,

programmes, music, teasers, everything. Since digitization may be a time

consuming process, this generally means that one must have separate

systems for the production work and the playout, because the playout system

cannot be utilized for any other work while the broadcast is going on. If you

do decide to share a single system for production and playout, remember

that you must have large amounts of hard disk space and that you must plan

in advance to share your time across these two functions.

Most playout softwares are compatible with MP3 format files!

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Organising and managing the sound files in the playout system is the most

demanding part of using the system. If sound files are not named according

to a common convention and properly organized, the playout system

becomes completely chaotic and it becomes impossible to find specific

sound files. It is essential that everyone who uses the system knows how the

sound files are organised. Since a number of people – community reporters,

station manager, community volunteers – may be operating the system, this

process must be set up when the system is first installed. Usually, the computer

is set up with a folder where music sound files are saved, a folder for ads and

jingles, a folder for finished productions such as interviews, one for sound

effects and so on. Some systems already have folders for storing different

items but will still rely on the user to label the item or save it in the right place.

Playout systems make the presenter’s job much easier. At the same time, the

station will need extra computer skills to maintain the playout system, and

this can make the technical department’s work more difficult. These skills

can be difficult to learn and so it is important to have a good relationship

with your supplier to talk through problems as they arise.

Digital automation systems – the next step

The digital automation systems are the next higher step beyond the audio

playout systems, allowing us to automate the entire task of broadcasting

programmes according to a pre-decided schedule. Once specific time slots

have been set for various programmes to air, and for the programmes to be

interrupted at specific points by advertisements, public service

announcements and programme promos, the digital automation system

allows us to simply line these up for several days in advance, for the

programmes to play out completely without human interference.

Naturally for this system to work to its true potential, this means having a full

time team to manage and organize the audio on the system, not to mention

full time teams working on generating the programming and the advertising

(especially if the programming team is also producing the advertisements on

behalf of the advsertisers). It also means an enormous level of coordination

and cooperation between these teams in terms of getting the relevant audio

ready several days in advance of the play date.

Folder systems and file naming conventions are sometimes dependent

on the specific playout software being used.

Given the scale of operation of a CR station, automation must be

used with care. Extensive automation also means having a full time

infotech team that can manage and maintain the computers involved

at all times. This is only a viable option if your station is doing more

than 8 hours of broadcasts a day.

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(AUDIO) EFFECTS

Audio effects can be of two kinds: The ones that are actually recorded from

a source – a car passing, say, or a baby crying – and the kind that are

generated artificially to change the audio quality of a recording or emphasize

something (a whistle or bloop or thweep, for instance).

Properly used, effects can add a whole new dimension to recorded sound.

Effects can make advertisements more appealing; dramas more dramatic;

and jingles ear catching. Nearly all computer-based digital-editing systems

now come equipped with a toolbox of effects – but it is often simplest to

record the kind of sounds we want, unless we want something quite unnatural

which can only be created artificially.

Of the many effects that one might use in radio work, the most common and

popular are as follows:

1. Reverberation

Reverberation (or reverb) is the natural reflection of sound from walls and

structures around us, which give a voice its ‘presence’ in an enclosed space.

These reflections reach us so quickly after the original sound is made that

we don’t consciously perceive them as being separate from the main sound

– but we can and do notice when they aren’t there. (This is why a padded

room or an acoustically treated studio floor, where reverb has been

deliberately reduced through various techniques, sounds ‘dead’ to us, as if

our voice has been swallowed up by the room.)

For audio recording purposes, we always try to record ‘clean’ sound – that

is, sound without reverberations in a controlled studio environment. Later,

during post-production, we add the ‘reflections’ electronically, to the exact

degree that we require. Doing this well is an art, and calls for sharp ears and

an understanding of what real reverb sounds like. Done properly, it can

create the impression of a real room of a specific dimension.

2. Echo

When the reflection of the original sound reaches us after a distinct delay,

we perceive the reflected sound as an echo. In electronic terms, we can add

echo the same way we add reverb, but by increasing the return time.

3. Delay

Along with echo and reverb, we can also electronically create multiple

reflections, and alter the duration and volume at which each of these echoes

return after the original sound. This is achieved by using the delay effect

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controls. If the delay effect is used in combination with the pan control (see

below), this can create spatial effects in stereo.

4. Modulation

Modulating the delay time creates modulation effects. If we use a low

frequency oscillator to generate a signal that varies the delay time in

accordance with the frequency of the oscillator signal we can create a chorus

effect, like two or more voices singing the same part, but with slight differences

in timing and tuning.

Using different length delays and different modulating frequencies can also

create effects like:

Phasing: Very short delay time and mixing the delayed sound with the

original creates a slightly flatter and ‘treated’ effect;

Flanging: A longer delay and feedback creates the effect that we hear when

a guitar string is stretched sharply in the middle of a note;

Vibrato: When only the delayed sound is used, with a slight change in

pitch, to create a wavering sound that is more tremulous than the original.

5. Pitch shifting

Pitch is a measure of the overall combination of frequencies in a sound or

voice. (Hence: "She has a high-pitched voice" – that is, a voice where the

shrill notes and higher frequencies predominate.) Before the advent of

modern effects processors, pitch shifting was achieved by speeding up or

slowing down the recording during playback – the former increased the

pitch, and the latter decreased it. Unfortunately this technique also changed

the overall length of the audio. Modern effects processors can pitch shift

the sound – make it shriller or more bassy – without changing the speed of

the audio.

6. Time stretching

Another sound effect that is possible with modern effects processors is the

time stretch, where the length of the audio can be changed without affecting

the pitch of the audio. (See Pitch shifting above.)

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ELECTROMAGNETIC SPECTRUM

Radio waves are a form of electromagnetic radiation: Electromagnetic

radiation is the transmission of energy in the form of waves that have electrical

and magnetic components. Where scientists once thought magnetism and

electricity were entirely unlinked phenomena, research over the last few

centuries proved beyond a doubt that not only were the two linked, in many

cases they were simply different expressions of the same energy.

The most familiar forms of electromagnetic radiation are radio waves and

visible light waves. They differ primarily only in the frequency and wavelength

of the radiation.

All electromagnetic waves travel through empty space at the same velocity

(speed) – namely the speed of light. The speed of light (often denoted by the

symbol ‘c’) is 2,99,792,458 metres per second. For most calculations the

approximate value of 3,00,000 km/s is used. This is true whether we are

talking about radio waves or visible light.

Fig 11. The Electromagnetic Spectrum

Mathematically, electromagnetic waves are represented by sine waves.

The sine wave is a graphical representation of wave phenomena. As we

have seen earlier, the wavelength and frequency of any electromagnetic

wave are related to one another inversely; that is, when one increases, the

other decreases.

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We can now quantify this as an equation as:

Wavelength = Speed of light / frequency

Different forms of electromagnetic radiation are characterized by their

wavelength and frequency. When electromagnetic waves are ordered by

frequency or wavelength, this ordered array is called the electromagnetic

spectrum. The electromagnetic spectrum represents all electromagnetic

signals, from very low frequency (long wavelength) to very high frequency

(low wavelength). Note that even visible light, the electromagnetic radiation

that our eyes have evolved to perceive, is itself composed of a variety of

frequencies of light: The colours of the rainbow that we see when sunlight is

refracted or broken up by a glass prism are the different frequencies of light

that together make up (white) sunlight.

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EQUALIZERS

Many of us are already familiar with the treble and bass controls on our

home stereos, that let us control whether the sound is higher or deeper

in pitch.

For more on pitch, see Section B: (Audio) Effects on Page 175

Consumer grade equalization controls

The tone and bass controls are the most basic equalisers, allowing you to

change the overall mix of frequencies in the audio to suit our listening

experience, the listening area we are hearing the audio in - or to emphasize

specific instruments or voices in the audio. Essentially, they act as a sort of

electronic filter, allowing you to turn up certain frequencies in the audio,

and turn down others.

A slightly more advanced version of the treble and bass knobs is the graphic

equalizer, which is often found as a set of sliders on hi-fi consumer equipment.

Each slider controls a specific band of frequencies, with the entire range

from 50 Hz to 20000 Hz divided among 6 or 8 sliders. These are better than

simple tone knobs or controls.

Professional grade equalizer controls

The equalizer controls on professional equipment are a lot more precise

than the band equalisers found on home and consumer grade equipment.

(Band equalizers are so named because they are not very precise, affecting

a large group of frequencies together rather than a single frequency or a

small range of frequencies.)

On studio mixers, one typically sees an equalization section that includes

HI, MID and LO knobs, as well as an EQ button. Pressing the button activates

the equalization section, and using the three knobs turns up or turns down

the gain for the three equalization/filtration units.

The LO knob is a high-pass filter, which means it only low frequencies.

The HI knob is a low-pass filter, which means it cuts or boosts only high

frequencies.

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Fig 13. Effect of a hi cut/low pass filter

The MID knob is a bandpass equalizer. It typically affects frequencies between

500 Hz and 5000 Hz (the frequencies most commonly falling within the

human vocal range). On many mixers the MID equalizer is also tunable, in

that the centre frequency can be changed: This is the frequency in the exact

middle of the range that this knob controls. This form of EQ is also known as

a sweep equaliser.

Parametric equalization

The parametric EQ is very like the sweep equalizer in that it controls a band

of frequencies. In addition, it has a third control that allows the width of the

band to be adjusted. This is referred to as the ‘Q’ of the control: A higher Q

means a wider band of frequencies is being controlled, and a lower Q

means a smaller band of frequencies is being controlled.

Fig 12. Effect of a low cut/hi pass filter

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Don’t use equalization when recording audio unless there is no other

way. Most of the time, audio is poor only because our microphone

position or recording area is not up to scratch. Use equalization only

at the post-production stage – and in moderate amounts.

Software based equalization

Many audio editing and processing software now include equalization

sections where you can perform the same function, sometimes in an even

more precise way. Often these softwares have graphical representations of

the equalization controls, to make them comfortable for those used to

hardware mixers.

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(ACOUSTIC) FEEDBACK

Acoustic Feedback is most often experienced as the nasty screeching you

sometimes hear coming out of speakers at a concert, or when someone is

talking over a public address system. It is a high pitched sound that rises

quickly to a shriek – and is not only unpleasant to hear, it can be downright

dangerous for your equipment. Feedback is also known as howlround.

Feedback is produced when an unwanted sound output (or audio signal)

from a loudspeaker or audio device is fed back to an earlier part of the

sound reproduction system. The unwanted audio signal is picked up and

amplified (made louder) by the electronic circuits in the system. The amplified

sound is then output again over the speakers, and is picked up again by the

inputs (microphone), making a closed loop. The system then quickly becomes

overloaded, and this is heard as a nasty screeching sound through the

loudspeakers.

Typically, feedback happens when the speakers in a public address system

are placed behind the microphone, giving the speaker output a chance to

go back to the input and be amplified. To stop feedback, you have to break

the feedback loop. In the example described above, you will have to move

the mic to a place where sound coming from the speakers is not picked up

by the mic. Or you can move the loudspeakers so that their output cannot

reach the mic. Moving either the speakers or the mic will break the feedback

loop, and the system will work properly.

Fig 14. Poor speaker placement leading to ‘howlround’ – the speakers should have been

placed between the mic and the audience.

Avoid situations that will lead to acoustic feedback for two reasons:

Firstly, it always affects your sound output. The noise is horrible and it will

make your sound unlistenable. Even a small amount of feedback can cause

echoes or boosting or cutting of certain frequencies.

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Secondly the very high signal levels associated with feedback can destroy or

damage loudspeakers and other equipment that are part of the feedback loop.

Acoustic feedback is not acceptable at all in the broadcast studio. To make

sure feedback from the mic to the loudspeakers doesn’t happen, broadcast

studios have special switching units. These units, often incorporated into

the mixer, turn off the studio loudspeakers whenever a microphone is turned

on. The same switching unit also normally triggers the RAG lights or On-air

lights. These are indicator lights placed inside and outside the studio to

show that a microphone is switched on, and that someone is ON AIR. It is

good practice never to enter or leave the studio when the on-air light is on.

Another kind of in-studio feedback relates to recording equipment. For

example, let us assume a recording device is being used to record a signal

from the recording output of a mixing desk. If the recorder’s output is added

to the mix on the mixer’s recording bus, and you lift the fader of the channel

feeding the recorder, feedback will occur. The audio is feeding back into the

system, and the same kind of noise will result.

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FIELD RECORDERS

The term field recorder refers to any portable recording device that allows

reporters to go into the field with the means to capture sound. Because there

are so many different kinds of field recorders you can buy, it is impossible to

enumerate every type that is available in the market. But we can quickly list

the most popular varieties.

1. Cassette recorders

Cassette recorders are the most common field recording devices available

in many places even today. The cassettes that we use in them are readily

available almost everywhere, and are quite cheap. They are relatively rugged,

easy to repair – cassette recorders are plentiful enough for even the average

electronics repairmen to fix the common problems – and are relatively

cheap. Good cassette field recorder models are the Sony Recording Walkman

series, and (a little more expensive, but with far more controls for professional

grade work) the Sony TCD-5M recorders.

For more on cassette recorders, see Section B: Cassette Tapes & Cassette

Recorders on Page 134

2. Minidisc recorders

The minidisc or MD was originally invented by Sony as a replacement for its

cassette walkman players – that is, as a handy portable recorder that could

carry high quality audio. It never found acceptance in the home consumer

market, as it was an expensive device. Instead, it became popular with

filmmakers and journalists as a way to record high quality digital stereo

audio. MDs have been the staple recorder for a number of CR stations

across the globe for some time. The newer Sony HiMD models – an upgraded

version with higher capacity media and the ability to record PCM WAV

uncompressed audio – are still quite popular. The recorders are priced

quite reasonably for the quality of recording; and the HiMD recorders offer

the additional option of digital USB transfers for editing on a DAW, making

them an attractive option.

For more on MD recorders, see Section B: Minidiscs & Minidisc Recorders on

Page 204

3. Flash recorders

The most recent type of field recorder – and by far the ones gaining greatest

ground today - are the solid state flash recorders that record on Compact

Flash (CF) media or Secure Digital (SD) cards. As digital memory has improved

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in tandem with the increasing roles computers play in our lives, flash recorders

– which use the same kind of solid state memory used in computer BIOS

memory – have also improved by leaps and bounds. The most recent versions

– like Zoom’s H-2 recorder or the Edirol R-09 – are very high quality

instruments, with the ability to record several hours of high quality audio on

media that are rapidly becoming cheaper by the day. (SD cards are available

in 8 GB versions today, enough for over 10 hours of non stop recording in

uncompressed WAV format; and CF cards are available in as high a capacity

as 64GB.)

For more on flash recorders, see Section B: Flash Recorders on Page 187

Contd...

Conducting a field recording

A field recording normally involves the following steps:

1. Connect the microphone to the recorder. The microphone cable

usually has a female XLR or connector at the microphone end, or it may

be built into the recorder. The recorder end of the cable could use a

variety of input connectors, including male XLRs and ¼" mini-phono

plugs. Make these connections gently and correctly, and never force

the connectors to go in. Remember to press down the tab on XLR

connectors. Field recorders are often made of lightweight materials, and

force may crack the case or break the connector mount.

2. Connect headphones to the recorder. Smaller field recorders come

with earbud style headphones. Pro models often need to be matched

with full size headphones. Gently push the ¼" plug or minijack plug

into the jack for the headphones. If your full size headphones need a

plug adapter to make them fit, be sure to attach this first.

3. Insert the media. Follow the operating instructions of your recorder

and gently insert a recordable tape, MD, flash memory chip (or other

appropriate blank medium) into the recorder. Always ensure that the

inserted medium is fresh/blank. If there is already a recording on it,

ensure that you will not accidentally erase it while doing the new

recording.

4. Switch on the recorder and check your levels. Start by conducting a

short test recording to check your recording levels. Switch on and hold

the microphone in the position that you expect to work with it. Say a few

words, and ask your guest to speak as well. Keep your eyes on the audio

level meter. (Some recorders may require you to put them in REC-PAUSE

mode to do this.) Change the record levels on the recorder, or adjust the

mic position till you are happy with the levels. Check audio quality on

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the headphones as well, so that you know there are no unnecessary

crackles or loose connections.

5. Make the recording. Different recorders require you to press different

combinations of buttons to start the recording process. Confirm the

exact process to start and stop recordings before you commence your

recording.

6. Complete your recording, and label your media or identify it in

some fashion. Many reporters/recordists use sticky notes or insert labels

that can be written on to identify tapes/MDs/CDs. It’s a good idea to also

keep a notebook or pad close to hand to note good takes and pre-select

sections of recordings at this stage itself.

7. Pack your equipment in their cases. Carry a checklist to ensure that

all the bits and pieces have been packed up and not left on location.

Coil all the cables neatly and stow them so that the connectors do not

get accidentally damaged. Make a note of any equipment that has been

malfunctioning. Pack your used media separately.

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FLASH RECORDERS

Till a few years ago, the first choice of field recorders for CR stations used to

be cassette recorders and minidisc recorders. But with computers and

cheaper memory becoming rapidly available – and therefore increasingly

becoming a part of even smaller stations – the stage was set for a new type of

device that could give very high quality digital recordings, and yet be very

compact and rugged.

This new type of recorder was the device that is now popularly called the

flash recorder, as it records on various types of flash or solid state memory.

Many of us are familiar with flash memory in the form of the thumb or USB

drives that have increasingly replaced the use of floppy discs over the last

few years.

Flash memory

Flash memory is a comparatively new type of data storage system, and is a

considerable improvement on hard disk and tape based digital storage

systems (like that used in the Digital Audio Tape, DAT) as it has no moving

parts. It uses an electronic chip that is essentially the same as the BIOS

memory in your computer. Each of the chips contains thousands of electronic

transistors, tiny ‘gates’ that allow electrons and charges to move from one

part of the chip to the other.

In flash memory - more correctly known as EEPROM memory - the data

is stored as a change in the conducting parameters of the electronic

chip itself: That is, as a property of these individual transistor ‘gates’. To

change the state of each gate takes an electronic input – but the best

part is that though it takes power to change the state of the transistor,

once the power is withdrawn, the state of the transistor remains static.

This means the chip does not forget the information once the power is

withdrawn. This type of memory is also known as non-volatile memory

i.e. memory that does not vanish when the power source shuts down.

(Contrast this with the fact that computer RAM, which also stores

information while the computer is on and running, ‘forgets’ all the data

when the computer is shut down – this is called volatile memory, and

means that a computer has to automatically write all the data in the

RAM onto the hard disk for later retrieval before it shuts down.) Since

the amount of power required to operate with flash memory is also very

small, and since writing information to flash memory involves no moving

mechanical parts, this also means a very small power source can go a

long way.

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Types of flash memory

Flash memory is available in an incredible variety of shapes, sizes and

capacities: You see MMC cards in mobile phones, SD and Micro SD cards

in cameras, and CF cards in a variety of instruments. For audio, the two most

common recording media are SD (Secure Digital) cards and CF (Compact

Flash) cards, with the former rapidly outdistancing the latter.

1. Secure Digital cards (SD)

SD cards are available in capacities ranging from 16MB to 4 GB (though

commonly the maximum used in many recorders is 2 GB, which gives

approximately 3.5 hours of uncompressed professional grade audio).

By convention, they are small blue chips about twice the size of your thumb

nail, with the golden electronic contacts exposed at one end.

SD cards have a small notch at one corner: This helps you identify how to

orient and insert them into the slot that is provided for them on audio recorders

and cameras.

2. Compact Flash cards (CF)

CF cards are an earlier development in flash memory, and are slightly bulkier,

being about the width and breadth of a box of matches – but the extra

dimensions also mean a staggering amount of information can be stored on

them. The most recent types of CF can store as much as 64 GB of data,

though 4 GB and 8 GB are more commonly used in audio recorders.

CF cards are also thicker than SD cards – which actually means a couple of

millimetres, so don’t go imagining something very thick! – and have a series of

slots across one edge: This is for the connector, which usually has 50 pins.

Flash recorders

Given the type of memory it uses, the flash recorder has several things to

recommend it over other types of recorders:

1. It is noiseless

2. It has no moving parts, and therefore fails less

3. It allows faster access to your data, and in a non-linear way (more like a

computer does)

4. It is lighter and smaller

5. It consumes very little power

6. It can be connected directly to a computer via USB for direct digital file

transfers with a minimum of fuss and complexity

All these together make the average flash recorder very small, compact,

rugged and battery conserving – all very important factors for field

recorders.

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Selecting a flash recorder

Flash recorders range from the basic dictaphone varieties (with an inbuilt

mic, meant mainly to record voice for notes and in field dictation, like

the Samsung Voice Pen or the Olympus DS-2200); to the higher end

dictaphone units (still meant for dictation, but often with provision for

external mics, like the Sony ICD-B 500 or the ICD-MX20); the middle

end professional units (like the Edirol R-09 or the M-Audio Microtrack

24/96); and the high end professional units (like the Marantz PMD 670

and 660 or the Tascam HD-P2, with XLR inputs and advanced controls).

There are flash recorders today to suit every pocket and budget, so you

will have to consider the key features one by one when you purchase a

flash recorder. Important considerations include:

1. What is the maximum memory it can take? (in case you upgrade it

later)

2. What kind of VU meters does it have?

3. What kind of batteries does it use, and how many?

4. What kind of memory does it take (SD cards are rapidly becoming

cheaper than CF)

5. What kind of connectors does it have? (XLR or mini phono?)

6. Can it be powered externally if required? (Most middle and high

end recorders come with power adapter provisions)

7. Does it have an internal mic and a built in speaker? (Depending on

the kind of field recordings you do, you may want to operate without

an additional mic, or even listen to the audio without headphones.)

8. What kind of audio file formats can it record in, and at what sampling

rates? (Higher end units offer WAV and MP3 recordings at a variety

of settings – lower end units may not offer uncompressed audio at

all, as they may have smaller memories. This is especially true of the

Dictaphone varieties, which have non-removable memories, and

which are optimized for long recordings in the field rather than high

quality audio).

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Fig 15. Cross section of a speaker unit

LOUDSPEAKERS AND STUDIO MONITORS

In a sound studio, we don’t just listen to sound – we monitor it, with attention

and focus, so that we can perceive small distortions, issues with diction, or

small changes in tonality. Naturally, this is a process that calls for a high

quality pair of speakers, so we can hear the audio that’s coming off the mic

or off our recording system.

From a mechanical/electronic point of view, the speaker is the exact reverse

of the microphone – it is a transducer that converts the electrical audio

signal into physical movements of a surface which then generates pressure

(sound) waves that we can hear with our ears. A good speaker, like a good

microphone, should conduct this conversion process with a minimum of

distortion or change in audio quality.

For more on microphones, see Section B: Microphones on Page 198

The electrical signal from a mic or a recorder is too weak, of course, to drive

a large surface back and forth, so speakers are generally used in conjunction

with an amplifier, which can boost the signal to a strength where it can

‘drive’ the speaker.

For more on amplifiers see Section B: Amplifiers on Page 128

The speaker consists of three main sections: drivers, a cross over network

and an enclosure (the speaker box).

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The input wires for the speaker carry the audio signal to the driver unit,

which is essentially a cone of stiff cardboard (in consumer end speakers)

and Kevlar plastic (in higher end speakers). The narrow end of the cone is

connected to a coil of wire (the voice coil) that is wrapped around a

permanent magnet. The amplified audio signal is fed to this coil, which then

acts as an electromagnet, and alternately is repulsed by the other magnet

and attracted by it. These movements are dependent on the frequency and

strength of the electrical (audio) signal fed to it, which – of course –

corresponds to the frequency and strength of the original audio.

The movements of the voice coil are transferred to the cone, to which it is

attached; and the vibrations of the cone make the air in front of it vibrate as

well, which is what we perceive as sound.

Woofers and tweeters

We have already seen that the audio signal must be amplified in order to drive

the speaker cone back and forth. It stands to reason that if the cone is large, the

amplification must correspondingly be greater. Most good speakers, therefore,

use a combination of two driver units, a smaller cone handling higher

frequencies (tweeter) and a larger cone (woofer) handling low frequencies.

Such speakers need a crossover circuit to channel specific frequencies to

the two driver units

The enclosure

Usually, the drivers and all the related circuitry, including the surface on

which they are mounted, are encased in a heavy box or enclosure, often

made of wood. This not only serves to keep all the components together, it

also keeps them all in the correct position relative to each other. Additionally,

since the drivers are moving quite fast, and set up powerful vibrations, the

enclosure is heavy in order to be able to absorb the vibrations.

Enclosures are carefully designed and calibrated to provide the best sound

experience: The hollow space serves as a resonator – that means the column

of the air inside it vibrates at the same rate as the sound produced by the

speaker drivers, increasing the sound output. This is also supported by the

design of the vents surrounding the main driver cones, which are designed

to direct the backward reflections to the front.

Passive & Active monitors

Most studio monitors are passive monitors: That is, they are connected to

power amplifiers, that in turn are connected to the mixer. The levels of the

audio signal reaching such monitors are generally controlled from the mixer

itself. Some monitors, however, have power amplifiers built in. Such monitors

are called active speakers, and they’re considerably more expensive.

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With passive monitors, there is a possibility that we will overdrive the speaker

drivers – that is, give them a signal input that is beyond their capacity,

thereby damaging them. With active monitors this is not a worry, since the

amplifier and the driver are a matched set. (Having matched amplifiers often

makes active speakers sound better as well!)

Speaker cones must be protected from dust and direct sunlight – and

most of all from curious pokes by people!

Headphones & Earphones

Headphones are small paired speaker units

fitted in a plastic or leather casing which is

designed to be worn over the user's head. (The

headphone's smaller cousin, the earphone, has

two small speaker units enclosed in small plastic

holders designed to fit within your ears.)

Headphones can be used in both studio and

outdoor situations. In studio situations,

headphones are often used to prevent acoustic

feedback when there are live microphones

around. In field situations, headphones prevent

extraneous ambient noise from disturbing your concentration on the

audio that is being recorded.

The primary sections of a headphone unit are:

1. The Head strap/headband: An elasticized band that holds both

speaker units together and allows the user to fit them over his or her

head.

2. The Ear cups: Made of plastic or leather, the ear cups enclose the

speaker units and have a covering of soft felt, vinyl or leather that

allows the speakers to fit snugly over or against the user’s ears.

3. The Lead: Headphones are generally designed to monitor stereo

audio. This is why there are two speaker units, and the input cables

are paired: A main stereo cable usually splits into two independent

left and right wires that feed each speaker unit.

4. The Jack/connector: Headphones and earphones are generally

equipped with stereo connectors, usually 1/4th inch or 1/8th inch

miniphono stereo jacks, as headphones are inherently intended to

be monitor stereo audio. (Correspondingly, most smaller field recorder

units are equipped with miniphono sockets, and most pro field

recorders with regular phono sockets: The assumption is that pro

recorders will be used with full scale headphones, and smaller

recorders with earphones.)

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MAGNETIC RECORDING

Magnetic recording is an analog recording process, and works on the

principle of electromagnetism. Magnetism and electricity are linked

phenomena, which means that an electrical current passing through a

conductor like a wire or a piece of metal generates a magnetic force that is in

proportion to the strength of the current. (Similarly, if a conductor is placed

in a moving magnetic field, an electric current is generated within the

conductor.)

In magnetic recorders – typical examples are the cassette and the spool

recorder - the input electrical signal from the microphone (or any other

audio signal source) is fed to a recording head, which is essentially a soft

iron core with a wire coil wrapped around it. A motor unit moves a rubber

or plastic capstan and pinch roller system that grips the tape surface and

moves it under the head at a constant pace (usually 4.76 cm/second). As the

input current varies according to the changes in the audio, so does the

magnetic force generated in the iron core of the head. This varying magnetic

force is recorded onto the tape as a rearrangement of the magnetic particles

on the tape surface.

Fig 16. Recording on a magnetic tape organizes the magnetic particles on the tape in

response to the input signal

When the recorded tape is then played back, the tape is moved across a

second head – the playback head – where the reverse process takes place:

The magnetic field generated by the particles on the tape generate a

corresponding current in the iron core of the head, which is drawn off by the

wire coil and can then be amplified and played back over speakers, recreating

the original sound. In professional magnetic recorders, the recording and

playback heads are often separate, but in most consumer grade equipment,

the same head performs both functions.

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Fig 17. The magnetic recording head

The primary issue with the media - tapes, floppy discs - used in

magnetic recording is that they can be easily damaged by heat, or

any stray elecromagnetic fields in the vicinity.

Tapes and floppies can be damaged if they are left near computer

screens, speaker sets, any powerful magnets - or even, sometimes, if

they are locked up in a metal drawer or almirah!

Additionally, the tape base is actually an emulsion containing magnetic

particles; and this often attracts mildew and fungus if the tapes are not

used or aired out a bit on a regular basis.

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METERS AND AUDIO LEVEL MEASUREMENT

Almost all audio equipment used in a radio station has an audio level meter

of one kind or the other. Maintaining audio levels is important: The circuitry

in every audio equipment has a capacity beyond which it will not be able to

handle the voltages and currents involved. If we feed the equipment a signal

beyond its capacity, at best the audio will be distorted – and at worst, it will

damage the equipment. Similarly, if the audio levels are too low, then the

system’s own noise will drown out the usable signal.

For more on Signal to Noise Ratio, see Section B: Signal to Noise Ratio on Page 214

Audio meters are also necessary so that we can match levels across pieces

of equipment, keeping the quality of the audio high.

Different pieces of equipment carry different types of meters, and it is vital to

know how to use each of these to gauge the audio levels properly:

1. The VU meter

The VU or Volume Unit meter is the most common analog meter type for

audio equipment. Typically, it has a graded meter with markings ranging from

around -20 VU to +3 VU. Till 0 VU, the meter is generally marked in green or

black, and beyond this, it is usually marked in red. A needle moves across the

meter to indicate the level of the audio that is being input into the equipment.

0 VU indicates the maximum distortion free level that the equipment can

handle. In practice, there is some scope for going beyond this: It is okay

if most of the programme is around 0 VU, with the occasional peak

reaching + 2 VU.

For more on dBu units, see Section B: Decibels on Page 172

Fig 18. The VU meter

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Lining up VU meters

VU meters on various pieces of equipment are often used to align the

equipment to a reference signal. For this, we use a source that plays back

a 1000 Hz (1 KHz) test tone at 0 dBu, and feed the source to all the

equipment that needs to be aligned.

The faders on the equipment to be aligned are then set to a standard

reference point (usually -10) and the channel gain turned up or down till

the VU meters on all the pieces of equipment reach -4 VU.

When all the equipment that we are using has been so aligned, it is good

practice to mark the gain setting at which this alignment has been achieved

on each of them – this way we can be sure that all the equipment is

reflecting the correct levels.

2. The PPM meter

In some equipment, it is more important to measure the highest levels of the

audio signal – the peak. Since the VU meter needle is in constant movement,

and doesn’t stop at the peaks, it is hard to note the peaks of the signal.

This is why some pieces of equipment – especially the master broadcast

mixer in large studios – are equipped with PPM meters or Peak Programme

Meters, which are designed and graduated specifically to measure the peak

levels of the programme.

In the PPM meter, the graduations are generally marked from 1 to 7. The

reference 0 dBu is equivalent to the 4 mark. The signal should be controlled

to not exceed the 6 mark

3. Digital meters (LCD or LED)

Modern digital audio equipment often carry a third type of meter called a

digital meter. These are often a part of the Light Emitting Diode (LED) display

Fig 19. The PPM meter

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on the casing of the machine; or are carried as part of the remainder of the

display on a Liquid Crystal Display (LCD) display built into the unit.

Unlike the analog VU and PPM meters, digital meters give no headroom –

that is, we cannot exceed the 0 mark on these meters. If we do, distortion of

the sound will almost certainly result.

Many sound recordists today tend to use the -12 dBu mark on the meter in

the same way as the 0 dBU reference on the older analog meters: That way,

the audio can exceed the reference level somewhat without still reaching

the 0 dBu mark, giving the same headroom as the analog meters. If we

record using this standard, it is wise to keep the softest sounds around -18

dBU to – 20 dBu, and the loudest sounds around – 6 dBu. When we finally

mix and master the sound, we can bring the whole programme further up

towards the 0 dBu mark.

Fig 20. The digital meter

LCD digital meters are composed of a series of dots or black boxes

that appear and disappear in response to the input signal. The only

permanent markings are two dots marked towards the right end of

the meter, and corresponding roughly to the 4 and 1 marks. Try and

keep recording levels on or around the first dot, with the peaks touching

the second dot (to the right) only occasionally.

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At its very basic, the dynamic microphone is made up of a thin plastic or metal

film attached to a fine coil of wire. The film – known as a diaphragm – is

usually stretched across the open end of the microphone, and the coil hangs

below it, suspended between the North and South poles of a powerful magnet.

When someone speaks in front of the diaphragm, their voices reach the

diaphragm as a series of pressure waves – changes in the pressure of the air

between their mouths and the diaphragm. The pressure waves make the

diaphragm vibrate back and forth, moving the attached wire coil across the

magnet. When the wire moves in the magnetic field, a small current is generated

in the wire. This phenomenon is called electromagnetic induction.

The important thing is that the current varies in direct proportion to the

movement of the diaphragm-coil combination – and since that is dependent

on the strength and frequency of the original sound waves striking the

Fig 21. The moving coil microphone

MICROPHONES

A microphone is a transducer, a device that converts one form of energy to

another. In the case of the microphone, the acoustic energy of sounds as

they travel through air get converted to a corresponding electrical signal

whose voltage varies in direct correspondence to the original sound waves.

This electrical signal can then be fed to a recording device or other audio

devices so that it can be stored for later playback.

Microphones are popularly referred to as mics (pronounced mikes). Today,

there are several varieties available, with specific functions and purposes.

We can understand how a mic works by looking at the simplest type of mic

there is: The dynamic or moving coil microphone.

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diaphragm, the current is actual in direct correspondence to the original sound.

This small signal, only a few microvolts strong, can then be drawn off and

amplified by a pre-amplifier, so that we can record or manipulate it further.

For more on pre-amplifiers, see Section B: Amplifiers on Page 128

I. Mics classified by construction

1. Dynamic mics

Dynamic mics are of the moving coil or the ribbon type. The dynamic coil

type is decribed in the example above. The ribbon mic also works on the

principle of electromagnetic induction, but the transduction in this case

takes place because of the vibrations caused in a thin aluminium ribbon

suspended in a magnetic field.

Dynamics mics are especially good for field recordings, as they require no

external source of power.

Examples: Shure SM 57 and 58

2. Condensor or capacitor mics

Just as dynamic mics make use of the principle of electromagnetic induction,

capacitor mics make use of the principle of capacitance.

Capacitors – also known as condensers - are electrical components where

two metal plates are separated by an insulating material. If a voltage is applied

across the two plates, the two plates get charged. If the distance between the

two plates now changes, the voltage across the two plates will change

correspondingly.

In capacitor mics, one plate of the capacitor is fixed, while the other plate

acts as the diaphragm, and can move freely in response to the sound energy

striking it. The change in the voltage caused by the movement of the free

plate – and the consequent change in the distance between the two plates –

is read as the audio signal.

Capacitor mics need a power supply to keep the capacitor charged. This

may either be supplied by an internal battery fitted in the mic; or through a

power supply provided through the same wires which carry the audio signal

away from the mic. If the latter system is used, the power supply is known

as a Phantom power supply. This is usually a 48V supply; and mics which

require such a supply usually include P48 within the mic name.

Capacitor mics are highly sensitive, and give very accurate sound

reproduction. This is why they are used extensively for broadcast.

Examples: Rode NT-1A, Sennheiser MKH 416 P48

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3. Electret condenser mics

Electret condenser mics are a variety of condenser mic where the capacitor

plates are permanently charged instead of requiring a continuous electrical

charge to maintain their voltage.

As they do not require a power supply, this means these mics can be very small

in size, allowing them to be used as built-in mics in several types of devices.

However, their audio quality is also poorer than powered condenser mics.

Electret condenser mics are usually found as the built in mics on consumer

grade home audio and portable audio equipment, especially smaller two-

in-one cassette recorders.

4. Carbon mics

Carbon mics are one of the oldest types of mics, and are used in old style

telephone handsets. They can only handle a frequency response of about

300 Hz to 3000 Hz, making them useless for broadcast audio.

5. Piezoelectric mics

The modern replacement for the carbon mic in telephone and mobile phone

handsets, these mics make use of the piezeoletric effect - the ability of

certain crystals to generate a small voltage when distorted mechanically in a

particular direction – to generate an audio signal. Their frequency response,

though better than carbon mics, is still not perfectly suited for broadcast –

but is often adequate for phone in programmes and on-location reporting in

the absence of other equipment.

II. Microphones classified by directionality

Microphones can also be classified on the basis of their directionality – that

is their ability to pick up sound from specific directions around the mic. This

is generally represented on a polar diagram, a 360 degree chart that shows

the pick up pattern of the mic.

The polar pattern or diagram generally shows the pick up of the mic at

various frequencies. Naturally, a mic that has the same or similar pick up

pattern at every frequency is to be much preferred.

Thus, on the basis of their pick-up pattern, mics are classified as

omnidirectional (where the mic picks up sound from all around it); or

directional (where the mic only picks up sound from specific directions).

Directional microphones can be subclassified into several types, based on

how directional they are. Among these, the most common variety is the

simple cardioid mic, so called because its pick up is mildly directional, and

looks roughly like a heart shape.

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Fig 22. Omnidirectional polar pattern

Fig 23. Basic cardioid mic polar pattern

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Most cardioid mics tend to pick up sound best in the direction that they

point to directly, with the highest rejection of sound being at the sides. There

are variations of the cardioid mic which are even more directional, and

whose pick up is limited to a very narrow area in front of the mic. These mics

are known as supercardiod and hypercardioid mics.

Hypercardiod mics often use additional accessories like a slotted interference

tube to heighten the directional effect. The long tube attached to the front

gives them an elongated appearance that suggests their other name: Tube or

shotgun microphones, since they often look like gun barrels.

The last kind of directional mic is the figure of eight or bidirectional

microphone, which is only sensitive to sound coming from the two sides of

the microphone.

The figure of eight microphone is usually only used for situations where one

mic may be used between guest and presenter, or where two singers share

a mic.

Fig 24. Hypercardioid polar pattern

Nowadays, many manufacturers use advanced electronics to make

mics that have switchable polar patterns. This lets the mic be used as

cardioid, bidirectional or omnidirectional mic depending on the

situation. (For example: The Sennheiser MKH 800)

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The proximity effect

An important consideration when using bidirectional and cardioid mics is their

response when the source of sound is very close to the mic. This causes the boost

of low frequencies in the mic’s pickup, an effect called the proximity effect.

Used well by an expert and trained presented, this can result in a full and

throaty larger-than-life radio voice. But used poorly, this can mean muddied

and dull audio.

Fig 25. Figure of Eight Polar pattern

Guarding against pop

Many sounds used as part of normal speech are plosive – that is, the

sounds involve the expulsion of gusts of air from the mouth. When

these sounds are made in front of a mic, the gusts of air can strike the

mic diaphragm, and cause a rumble that can distort the audio. (The

letters P and B, in particular are responsible for this.) The effect is called

pop or popping noise.

This effect may be reduced with voice training (which teaches the

presenter to say the plosive sounds without large pops of air); and by

using a pop filter in front of the mic. Pop filters are fine screens of fabric

or metal mounted on a small stand which may be attached in front of

the mic. The mesh breaks up the blast of air, and prevents it from hitting

the sensitive portions of the mic, thereby reducing the pop.

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MINIDISCS AND MINIDISC RECORDERS

The Minidisc (MD) format was introduced in 1992, by Sony. MDs were

intended to replace cassette tape as a new portable digital audio playback and

recording system. This meant it had to be small and able to withstand vibrations

and rough treatment outside the safety of the home or studio. Unfortunately

it never quite reached the same level of popularity as the compact cassette –

though its quality and compactness made it the de facto standard for

community radio and journalists till the advent of flash based recorders.

For more on flash recorders, see Section B: Flash Recorders on Page 187

The Minidisc

The Minidisc or MD is actually a small silvered disc contained in a plastic

case. In some ways it looks like a computer floppy disc, only much smaller.

The disc stores up to 16 bit, 44.1 KHz sampled digital audio through a

process called magneto-optical storage, which combines some aspects of

magnetic recording with the optical storage processes used in CDs. This

also makes MDs erasable and reusable with no loss of quality, which

contributes greatly to their use in the field.

For more on sampling, see Section B: Analog & Digital Audio on Page 124

For more on magnetic recording, see Section B: Magnetic Recording on Page 193

For more on CDs, see Section B: Compact Discs on Page 138

Being a digital storage medium, MDs can store audio as tracks, which means

we can search through them in a non-linear fashion: We can skip tracks we

don’t want to hear, and jump straight through to the recordings made at the

end. Information regarding the tracks is stored – like CDs – in a table of

contents file that is updated each time we record or erase a track.

A standard MD disc. The shutter moves aside

during recording to let the recorder access

the actual disc surface.

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MDs can record in both stereo and mono. At its basic short play (SP) setting, a

normal MD recorder can store up to 74 minutes of stereo audio on a single 300

MB capacity disc. This is doubled to 148 minutes if we record in mono. Audio

is recorded on standard MDs in a digital compression mode called ATRAC.

This means that audio from a standard MD cannot be heard on a computer

without special software that can play back ATRAC compressed audio

For more on stereo and mono audio, see Section B: Stereo & Mono on Page 217

In recent times, a higher capacity 1 GB disc has become available which is

meant specifically for use with the new generation HiMD recorders (see

MD & HiMD, below).

MD recorders

MD recorders are available in both studio models and portable field

recording units, though the latter are in more common use. Most of the field

units are very compact, having dimesnsions not much larger than the disc

itself. Nearly all of the models – primarily from Sony, Sharp and Tascam –

have menu based operations, with many of the settings and features accessible

only through a customizable computer-type menu.

MD recorders were built to be used in tough field situations, and have

acquitted themselves well in a variety of conditions with minimal care. Most

accept a mini-phono jack based external microphone, and contain an internal

rechargeable battery. Some can accept an additional external battery – usually

AA size – in an attachable external case.

MD and Hi-MD

To remedy the compression that was placed on the audio in MD recorders,

Sony came up with a variant of the MD called the Hi-MD a few yars ago. Hi-

MD recorders allow one the choice of recording in Hi-SP, Hi-LP or

uncompressed PCM WAV formats: All three modes record audio in a

proprietary Sony file format called OMG, which is then converted to

uncompressed WAV when transferred to a computer. (HiMD recorders can

also record in the older MD mode, in which case the PCM WAV option is

not available.)

Hi-MD recorders also offer the option of avoiding D/A conversion when

transferring or dubbing the audio onto another recorder: Where regular

MDs could do this only through the line out jacks (that needed a mini-

phono plug and cable to be plugged in), HiMD recorders allow transfer of

the audio as a digital file through the USB port built in to the recorder.

Hi-MD recorders can play older MD discs; but discs recorded on the

HiMDs in PCM WAV cannot be played back on the older recorders.

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This is highly useful, as it avoids D/A conversion related losses, and saves

transfer time.

For more on D/A conversion, see Section B: Analog & Digital Audio on Page 124

HiMDs recording in PCM WAV format give about 27 minutes of recording

on the standard MD disc, which is 300 MB in capacity. Newer 1 GB Hi-MD

discs allow one to record approximately 124 minutes of uncompressed

audio on a single disc.

Hi-MD is a recording mode, and is not related to the disc itself.

Any MD disc can be formatted to Hi-MD mode and used in a Hi-MD

recorder.

Taking care of MD discs

zDo not touch the disc by opening the shutter on the cartridge. The

shutter and disc will be damaged if the shutter is forced open.

zDo not place MDs in direct sunlight, areas of high temperature,

or high humidity.

zIf dust gets into the MD cartridge, wipe it with a soft DRY cloth. Do not

use any liquids to clean MDs.

zWhen putting a label on a MD, make sure it is fixed to the correct

position for labels on the disc. If the label is not properly fixed it may

roll up or come loose and could cause the cartridge to get stuck in

the MD player.

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MIXERS AND MIXING DESKS

At first sight, the mixer is a daunting sight. Even a comparatively small mixer

with only 4 channels on it seems to have way too many buttons and faders

for one to understand them all. But if one looks a little closely, one will

realize that the mixer is actually divided into sections, and that each plays its

own specific part in the overall process of controlling and managing audio.

Whether in the studio or the field, the mixer is the heart of the system.

At its most basic, the mixer is used to mix audio – that is, combine different

sources, adjust their individual and relative levels, and give us one combined

output which can then be fed to a recorder or a transmitter. Each source is

connected to a different channel, so that it can be controlled independently;

and all the channels feed the master channel, which controls the final output.

Note that in this diagram, the sliders or faders on each channel – which we

use to control the level of the input – are set to different points. Depending

on how loudly or softly the person in front of the mic is speaking, the fader

is moved up (boost) or down (cut). Levels may be seen on most mixers on

VU meters. There may be one or several meters, which may show individual

input levels or the final programme output level.

In this case, the three input channels form one mixing bus: One pathway

down which the combined audio will go before it reaches the master fader.

Fig 26. A basic mixer shown in schematic form

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Larger mixers with more channels may have more than one mixing bus,

letting us gang or group channels. This lets us select the inputs that will be sent

to a particular output. For example, during a live programme, which is being

transmitted directly from the studio, we may have two speakers and a music

source like a CD playing underneath their voices. For the live transmission,

we may have all three sources being channeled to a programme (mixing) bus,

from where the output goes to the transmitter. But we may want only the

voices to be recorded to a recording system - without the music - for archive

purposes...in which case we might also direct the two mic channels to a

second (recording) mixing bus, which sends its output to a recorder unit.

Many mixers will also feature some stereo and some mono channels, to

allow us to connect stereo sources and mono sources separately to the

mixer. Channels may also feature a PAN-POT knob, which allows us to

‘pan’ the input audio left or right when we are mixing stereo audio.

Mixers may also have an equalization section, where there may be an EQ

button along with LO, MID and HI knobs to control the relative mix of

frequencies in the input audio.

For more on equalization, see Section B: Equalizers on Page 179

Other features to remember when selecting a mixer

The illustration given on the previous page illustrates a 3 channel mixer.

In practice one should get a mixer with as many channels as one can

afford. This will allow you to add more pieces of equipment to the

studio without upgrading the mixer.

Additionally, many mixers come with A/B switches on each channel,

allowing you to keep more than one piece of equipment connected to

the same channel, but use the appropriate one as required.

Ideally, the mixer you select should offer more than one mixing bus,

allowing different mixes of signals to be sent to different equipment.

A broadcast mixer would also have stereo channels. These allow you

to control the left and right signals from a piece of stereo source equipment

with one fader.

Broadcast mixers should also be capable of controlling the operation of

source equipment: To start a CD player from the mixer itself, from example.

This is sometimes called fader start. Fader start means you must also

have playback and recording equipment that accept fader starts.

Mixer design and circuitry is a very specialized part of audio

equipment design. A good mixer with dependable and distortion

free circuitry is a very complex item, and very expensive. The mixer

is often the most expensive single piece of equipment in the studio.

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MODULATION

Modulation, at its most basic, means the combination of different waves.

This is a very important concept for radio transmission, because the whole

principle of broadcasting is based on the concept of modulating the audio

that we would like to broadcast.

Human ears are capable of hearing sounds between 20 Hz and 20000 Hz.

The average human voice ranges between 500 Hz and 5000 Hz, which is

directly in the middle of this hearing band. Our ears are tuned to listen

primarily to other human voices.

Now, let’s assume that we want to record and transmit a voice that is about

3000 Hz in frequency. A wave with a frequency of 3 KHz has a wavelength

of about 100000 metres. It is a principle of physics that we need an antenna

at least a quarter of the wavelength to effectively transmit the wave. This

means we need an antenna 25 km long to transmit our 3 KHz signal – which

is impractical, to say the least! The only way around this is to find a way to

raise the frequency of the audio in a way that allows us to use a more

conveniently sized antenna system. And this where modulation comes in.

For more on frequency and wavelength, see Chapter 1: So What is Radio &

How does it work? on Page 8

For more on antennas, see Chapter 5: Transmission Equipment on Page 72

We use modulation to ‘add’ the audio signal that we want to broadcast to a

high frequency (radio frequency) electromagnetic wave. The combined wave

then acquires the properties of both component waves. The audio signal

‘piggybacks’ on the radio wave, which is then called a carrier wave.

Fig 27: The modulation chain during transmission

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In radio broadcasting, modulation can occur in one of two ways:

The amplitude of the carrier wave can be modulated to carry the audio

signal. This technique is called amplitude modulation (AM).

The frequency of the carrier wave can be modulated to carry the audio

signal. This technique is called frequency modulation (FM).

Amplitude Modulation

Amplitude Modulation is the older form of modulation for radio. Depending

on the wavelength of the carrier wave, AM can be classified as Long Wave

(LW), Medium Wave (MW) and Short Wave (SW). Today, MW is the most

common form of AM transmission – All India Radio’s Akashvani and Vividh

Bharati stations broadcast on MW. Most MW stations broadcast on

frequencies between 535 KHz and 1605 KHz which correspond to

wavelengths of 560 to 187 metres. AM stations are usually spaced about

100 KHz apart.

In AM, audio information is combined with a carrier wave by varying the

amplitude of the carrier wave above and below its unmodulated value: The

changes in amplitude reflect the variations of the audio signal.

Fig 28: Amplitude Modulation

The biggest advantage of AM is that relatively modest output powers can

reach very long distances, often hundreds of kilometres. Shortwave (SW)

broadcasts can go even further – thousands of kilometers – and reflections

off the electrically charged ionosphere of the Earth’s atmosphere can increase

that distance further.

AM broadcasts can carry audio information ranging from about 200 Hz to about

5 KHz. This means the broadcasts are fine for voice, but often make music sound

scratchy, since many instruments have frequency ranges higher than 5 KHz.

The ionosphere layer of the atmosphere is more diffuse when the

sun’s radiation is striking it directly. It is denser on the night side of the

planet, when it is in shadow. Ionospheric reflection of SW broadcasts,

correspondingly, improves at night time.

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Frequency Modulation

Frequency Modulation involves modulating the audio signal with a Very

High Frequency (VHF) radio carrier wave in a way that the resultant wave

retains the amplitude of the carrier wave, but has a frequency that varies

according to the audio signal.

Fig 29: Frequency Modulation

This form of modulation makes broadcasts less susceptible to interference

from storms and stray electrical and magnetic influences – but it also means

a more limited transmission range for the same output power.

FM transmission is line of sight, meaning the broadcast antenna has to be

electronically visible to the receiving antenna. This is why FM stations are

typically local stations, and why FM is the modulation technique of choice

for CR stations.

Placing FM antennas at high vantage points can increase this range, as can

increasing the transmitter strength - but there may be physical limitations to

doing this, especially with reference to the technical guidelines covering

community radio stations in India.

For more technical parameters for CR in India, see Chapter 9: Community

Radio Guidelines in India and their Implications on Page 105

Commercial radio broadcasting is globally assigned frequencies between

88 and 108 MHz, at 200 KHz intervals. The extra bandwidth (200 KHz on

each side of the base frequency) means FM can carry higher quality audio

(20 Hz to 16000 Hz), as well as stereo signals. For digital audio, FM is

generally rated as being able to carry nearly CD quality audio, at about

96 Kbps/44.1 KHz sampling.

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PATCHBAYS

A patchbay, also called a jackfield, is one of the most useful items in a

studio. Anypne who has ever connected and disconnected any audio

equipment - especially a modern multi-component hi-fi system - will agree

that it can be a really painful process, especially if it has to be done multiple

times in a day.

We make the process of connecting and disconnecting inputs and outputs

to each other easier by using a patchbay, which is essentially a series of

electric contacts enclosed in a single housing. Different pieces of equipment

are permanently wired to one or more of the contacts (two contacts if we

want to keep the stereo inputs and outputs separate, one contact if we're

only working with mono). As per our requirements, we can then connect

any combination of contacts with short patch leads, which are short

connectors designed to connect patchbay contacts.

The most commonly available patchbays normally have 2 rows of 26 sockets,

with each socket on the top row paired with the socket below it. The top row

of sockets is for source equipment; the bottom row is for inputs to the mixer

or other recording or transmission equipment. For a small CR station, it may

be advisable to invest in modular patchbays, which are available in 4 + 4

sections: This means we can add more contacts as we require them and our

studio expands.

Fig 30: A schematic of a small patchbay

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This diagram shows a small patchbay, labeled as per the inputs and outputs

connected to it.

The top row of jacks are outputs, and are labelled as follows:

CD L and CD1 R: These are the Left and Right outputs from the CD Player

PGM L and PGM R: These are the broadcast mixer's Left and Right programme

outputs.

DAW L and DAW R: These are the Left and Right outputs from the Digital

Audio Workstation in the production studio.

The bottom row of jacks are inputs, and are labelled as follows:

CH 1 L and CH 1 R: These are inputs to the Left and Right inputs of Channel

1 on the mixer.

CH 2 L and CH 2 R: These are inputs to the Left and Right inputs of Channel

1 on the mixer.

TX L and TX R: These connect to the Left and Right inputs of the compressor

limiter.

Thus, while the CD Left and Right outputs on the top row might generally be

connected to the Ch1 L and Ch1 R inputs on the bottom row (that is, the

stereo inputs on Channel 1 of the mixer), in an emergency - when we need

to maintain or service the mixer, say - we can connect the CD player outputs

directly to the transmitter input, as illustrated.

A patch cord must always run from an output to an input: That is,

opposite ends must be connected on different rows. This is very

important - a small mistake in plugging together circuits can severely

damage equipment!

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SIGNAL TO NOISE RATIO

All through this manual, we have used the word signal whenever we have

wanted to indicate an electrical current that carries information. To this, we

will now add the word noise, which can then be defined as electrical currents

which carry no useful information.

Every electronic circuit that carries a signal inherently has some internal

noise. These are basically stray electric currents that are generated by the

machinery itself. In audio terms, you hear this noise as a hiss or as a crackle

or background pop under the main audio. (If we cut off the audio feed and

simply boost the output of the equipment to a monitor, the static noise we

hear is the internal noise generated by the equipment.)

One of the reasons we keep the signal level as high as we can - without

reaching the distortion or overload point, of course - is so that the signal

(useful) audio can be distinguished clearly against whatever background

noise the system generates: If the signal level is too low, it will be drowned

out by the system noise.

Given the variety of audio equipment available, and the number of

manufacturers, it would obviously be good to have an objective measure of

this difference between the signal level and the noise levels of the system.

This is why the signal to noise ratio was evolved as an evaluative reference:

To develop standards for the level of noise in a system. A high signal to noise

ratio means there is always a large separation between the signal and the

background noise. A low signal to noise ratio means a small separation

between the two, and therefore the risk that the signal and the noise may not

be clearly distinguished from each other.

Signal to Noise ratio - often denoted as S/N ratio in short - is measured in

decibels (dB). Thus, if the maximum signal level the equipment can handle

without distortion is 80 db, and the level of the inherent system noise is

20dB, the S/N ratio for that equipment is 80 - 20 = 60 dB. (In practice, of

course, the measurement is not as simple as this!)

The better the components and the grade of manufacture of an

equipment, the lesser the internal noise that it generates - and the

higher its S/N ratio. Given two pieces of equivalent equipment, the

piece with the higher S/N ratios will be distinctly more expensive!

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SOUND & AUDIO

Sound

Sound is the effect perceived by the brain when vibrations travelling through

the air stimulate the ears. These vibrations are conveyed through the air as

changes in the pressure of the air.

Anything that vibrates and is in contact with the air can create sound pressure

waves. These vibrations disturb air molecules causing waves of alternating

high and low pressure. The ear is a sensitive transducer that responds to the

changes in pressure. The pressure waves strike a sensitive membrane of

tissue inside our ears called the eardrum - which, as its name suggests, is

like a drum skin. The eardrum vibrates when the waves strike it, and pass the

vibrations on through three small bones to the inner ear. The inner ear

contains two chambers full of fluid, which are lined with fine hairs and

particles of calcium. When the vibrations reach these hairs, they are converted

into electrical signals which are passed on through nerves to the part of the

brain which processes these signals into the sensation we know as sound.

Sounds that we hear as being louder are caused by greater changes in air

pressure, which means the eardrum vibrates to a greater degree back and

forth (higher amplitude). Softer (or quieter) sounds are caused by lesser

changes in air pressure, which means the eardrum vibrates to a lesser degree

back and forth (lower amplitude). Loudness is a subjective measure and the

same sound may be perceived differently by different individuals.

For more on properties of sound waves, see Chapter 1: So What is Radio,

and How does it work? on Page 8

When we say human beings can hear sound in the range 20 Hz to 20000

Hz, we are saying the pressure wave changes at a rate between 20 times a

second and 20000 times a second. Looked at in another way, this is the

definition of sound, since only pressure waves between these two limits will

result in the sensation we call sound.

Sound waves travel through air at a speed of 344 metres per second

(1238.4km/h). This is measured at sea level at a temperature of 15 ºC.

The speed of sound is independent of frequency.

Audio

Audio is the word used to signify the electrical equivalent of a sound wave,

which we create through a process of electro-acoustic transduction.

The audio signal, as we should correctly call it, takes the form of a changing

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electronic voltage in the circuit, that rises and falls in exact correspondence

with the changes in the original pressure wave.

For more on transduction and microphones, see Section B: Microphones

on Page 198

We convert sound to audio in order to be able to manipulate and/or store it

for later playback. A microphone is used to convert sound to audio, whereas

a loudspeaker or headphone is used to convert the recorded audio back

into sound so that we ca hear it with our ears.

Most of the equipment in the radio studio works with audio signals rather

than directly with sound - so most of the equipment should correctly be

termed audio devices.

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STEREO & MONO

When we hear a sound, we tend to forget that we are actually hearing it with

both our ears. The purpose of two ears placed on opposite sides of our

heads is not, as widely assumed, for redundancy - 'one ear will continue

working if something happens to the other one!' - but in order to give us a

sense of spatial separation between different sounds.

We are able to create this spatial separation because of an interesting

phenomenon called phase difference. Sound, as we know, travels as a

series of waves, with higher pressure sections alternating with lower pressure

sections. When a sound is generated by a source on one side of us, it

reaches the ear closer to it by a shorter path, and the ear farther from it by a

longer path. What this results in is that though both ears hear the same set of

waves, there is a miniscule difference in the time it takes for specific parts of

the wave to reach each ear. Our brains use this to calculate the angularity of

the sound - that is, its position in front of us - and its distance from us. (This

allows us to create a mental picture of the soundscape in front of us that is

quite independent of what we see - this is why we can still tell the direction

of the sound when our eyes are closed!)

This is what stereo means - the ability to create a spatial perspective to

sounds we hear. When working with audio, we can create this effect artificially

by recording audio on two separate channels, and feeding the respective

channels to two separate speakers. By distributing signals between the two

channels, we can make the sound appear to emanate purely from one

speaker; from both to equal extents; or both, but with a slightly greater

emphasis on one of the speakers.

The effect is to create the phase difference we perceive when hearing naturally

with our ears. Naturally, to use this effect best, the ideal listening position should

be at a position exactly between and equidistant from each of the speakers.

If on the other hand, we used a single speaker - or fed the same signal to both

speakers - we would not be able to get this sense of spatial separation. When

we have only one channel of audio, we call the signal a mono signal.

Stereo & Mono connectors

As we need two channels of audio for stereo, we have to keep both channels

separated from each other when conveying the signal from one piece of

equipment to another. This is why all stereo equipment has two connectors,

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Fig 31: Stereo perception of sound. The various instruments sound as

if they are spread out in front of the listener even though we actually

only have two sound sources - the two speaker units.

usually labeled Left (or L) and Right (or R). Often the connectors are also

colour coded, with red connectors for the right channel, and white or black

for the left channel. It is important to make these connections properly, so

that the stereo image does not accidentally get mixed up.

Stereo connectors can be clearly indetified just by looking at them. RCA

stereo connectors, for example, come in a colour coded pair. Stereo phono

jacks are always of the TRS variety (Tip-Ring-Sleeve) with the three contacts

defined by two black bands near the tip of the jack.

Mono connectors usually use a single connector, or a phono jack with a

single black band near the tip. It is usually possible to make or purchase

cables that will let you feed a stereo output to a mono input, or a mono

output to both stereo inputs.

Mics: Mono and stereo

Unless you are using a stereo microphone - which actually combines two

microphones in a single body, and gives two discrete outputs - all mics are

mono, and give a single channel output. The stereo image that you see in

the final programme that is broadcast is built during the post production

process. This is what the Pan-Pot knob on the mixer is used for - to distribute

the so und between both audio channels.

For more on the Pan-Pot knob, see Section B: Mixers & Mixing Desks on Page 207

Remember, mixing in stereo or working with stereo sound automatically

assumes that the listener has equipment that will allow him or her to recreate

the spatial separation that you are building. If all your stereo programmes

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Mixing audio in stereo is not only more time consuming, it requires

more powerful equipment - in the sense of higher end computers

and speakers. Digital stereo audio also means larger audio file sizes

than mono. Finally, stereo transmitters give a smaller transmission

range than mono transmitters of the same power output rating.

will be heard on small single speaker transistor radios, it is pointless to

spend time, money and effort on doing stereo programmes in the first place.

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TELEPHONE HYBRIDS

A telephone hybrid makes it possible to talk to callers on-air - that is, it allows

people calling the studio 'live' to participate in a discussion with the presenter

over the phone that goes out as part of the transmission. Essentially, this

means the caller's voice is added to the mixer's output; and that the studio

sound - the presenter's voice - reaches the caller over the phone line.

Having a telephone hybrid system allows you to create greater interaction

with your listeners, and involve them in the programmes the station generates

in a much more active way.

What the hybrid does

There are two important considerations when connecting a phone line to

our audio systems:

1. The telephone system works on the basis of a continuous power voltage

supplied to the telephone instrument - we have to see to it that this does

not interact with our audio systems in any way, as this can cause damage

to our equipment (not to mention a nasty hum in the audio!)

2. The telephone carries both received audio (caller's voice) and sent audio

(presenter's voice) over the same wires. We need to use a system where

these two audio feeds can be handled independently and sent independently

of each other to their respective destinations: The caller's voice to the

mixed mixer programme output, and the presenter's voice to the caller

over the phone - but keeping both audio feeds at a balanced level.

Fig 32: A schematic view of the telephone hybrid

For this the hybrid uses three types of circuitry:

1. A difference amplifier that performs the task of separating the caller's

voice and sending this to the mixer;

Presenter/

Studio

Audio

(S)

Difference

Amplifier

Tel Line

(R)

S+R To Mixer

(R)

Balancing

Network

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2. An isolation element , which is actually a transformer that prevents the

telephone line power supply from being transferred into your audio

equipment;

3. A balancing network that balances the level of the presenter's voice

against the voice of the caller, and helps the difference amplifier subtract

the send audio. If the balancing network is not very accurate, then the

subtraction operation will not completely remove the send audio, and

the audio may be distorted.

The separation is noted in the hybrid specs as a negative figure in decibels:

The higher this number, the better the hybrid - and the more expensive it is

likely to be.

The signal that is sent from the mixing desk to the hybrid send input is called

a mix minus or cleanfeed signal. This is because it contains all the on-air

audio that you want the caller to hear, less the output of the phone hybrid

(which is the caller's voice itself.)

Most broadcast mixers already have a dedicated channel for the phone

hybrid to be plugged in, and have a dedicated mix minus already set for this

channel. If it doesn't, you will have to direct all the sources except the hybrid

output into one auxiliary mix bus, and use the output of this mix bus as the

mix minus to feed back to the phone line.

Using the hybrid

Most hybrids are rather straightforward to use - they may handle one line or

multiple lines, with lights that generally come on to indicate which line the

incoming call is on. Once things are set up, operation is as easy as pressing

the correct line button to connect the line to the audio feed. Most hybrids

also allow you to connect a standard telephone instrument to them in order

to make calls.

A good multiline hybrid should allow you to queue callers, and

switch between them easily.

In the case of some older (analog) hybrids, there is generally a null adjustment

that lets you tune the circuit for best audio quality. Modern digital hybrids

are excellent at signal separation, and do not need such tuning at all.

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TRANSMITTERS

The transmission system is the final step in getting a broadcast signal on air

and out to its listeners. And the heart of the transmission system is the

transmitter, the combination of circuits that turns an audio signal into a

frequency or amplitude modulated radio wave that can be broadcast.

Let's take a good look at the FM transmission system to understand what a

transmitter unit does.

Fig 33: Schematic view of FM transmission system

The process starts with the final programme output from the studio or playout

system. For our discussion here, and because FM has the capability to

handle stereo broadcasts, we will assume this is a stereo signal with left and

right channels.

The final programme is by now, hopefully, mixed and the levels corrected

properly already. But this is fed to a compressor/limiter unit anyway to

ensure that the signal is properly corrected to transmission parameters.

This unit applies compression and limiting to prevent the transmitter from

being overdriven, and to control the dynamic range of the audio.

For more on Compressor/Limiters, see Section B: Compressor/Limiters on

Page 149

The processed audio signal is then fed to a stereo encoder. The encoder

combines the two channels of audio - left and right - and also generates a

19 KHz pilot tone that is used by receivers to detect a stereo broadcast.

The output is said to be multiplexed, as it now consists of several elements.

(This often shortened to MPX, a labeling that you may find marked on the

outputs of encoders.)

Compressor/

Limiter Stereo

Encoder

STL

Composite

MPX Signal

Exciter

Lo-power

RF signal

RF Power

Amplifier

Composite

MPX Signal

HI power

RF signal Antenna

Processed Audio

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The multiplexed signal is now forwarded to the exciter unit, which generates

the radio frequency carrier wave. (As we have seen, for FM, this carrier

must be between 88 MHz and 108 MhZ in frequency.) The exciter also

modulates the carrier with the encoder's MPX signal, thereby creating a low

power radio frequency (RF) signal that can be transmitted by an FM antenna.

Exciters generally have an inherent power output of 30 - 50 Watts. For most

community radio stations - and especially those in India - this may be more

than enough as per the guidelines and the signal gain one is likely to get

from an appropriately matched antenna.

For more on transmitter strength parameters, see Chapter 9: CR Guidelines in

India and their Implications on Page 105

If more power than the exciter's inherent power is required, then one or

more power amplifiers may be added between the exciter unit and the

antenna, to boost the strength of the signal. (Commercial broadcasters often

boost the signal to several kilowatts.)

The final modulated and boosted signal is then sent to the transmitting

antenna unit, which radiates the modulated multiplex signal into space.

AM antennae are designed to be a quarter the wavelength of the station's

broadcast wavelength, which - given the high wavelengths used for AM

broadcast - mean the antenna unit and the tower on which it is mounted on

can often be very large.

FM antennae, on the other hand, can be much smaller. The high frequencies

used for FM transmission mean the wavelengths are considerably smaller,

and antennae can be about half the wavelength of the station's carrier

frequency. Typically, this means an antenna of 2 metres’ width or less. The

most common antenna used is a dipole antenna, which is omnidirectional,

and radiates equally in all directions.

When the multiplexed and modulated signal reaches the antenna what

happens is this: The RF signal flowing into the antenna creates a

corresponding change in the electromagnetic field around the antenna,

which moves away from the antenna at the speed of light. Since the RF signal

flowing into the antenna is changing constantly in response to the audio

signal, the electromagnetic field being radiated is also changing constantly.

The antenna on at the listener's end picks up this varying electromagnetic

field and the radio receiver's circuitry extracts the original audio from it

through a series of RF filtration circuits. The extracted audio can then be

amplified and played back over the transistor's speaker.

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UNINTERRUPTED POWER SUPPLY (UPS)

All of the studio and transmission equipment at your radio station requires

a source of electrical power to work. This is usually supplied by the AC

mains power supply provided by the local power company, which in India

is usually run by the government. (Though power distribution in some areas

has been privatized.)

However, many stations are located in areas where mains power supply is

unreliable. Unless you have back-up, a mains power failure will interrupt

your broadcast. This is a serious problem - remember, your listeners will

also be affected by the electricity failure, and will want to rely on their radio

station to keep them informed about it!

This is the purpose of an uninterrupted power supply (UPS). As the name

suggests, a UPS provides uninterrupted power to the station even when the

mains supply is disturbed.

There are many different UPS systems that supply varying degrees of back-

up protection. The choice of system for your station should be made after

considering the quality of the power supply in your area. For example,

stations located in areas that suffer from constant power disturbances will

need a more complete power back-up system than stations located in areas

where the power supply is more stable.

What can disturb the mains electrical supply?

The mains supply is meant to be a stable AC voltage of 220 volts at

50 Hz, but there are several kinds of power line disturbances that affect

the mains supply:

Lightning, power network switching and the operation of other high

power equipment in your building, such as elevators, spot welders and

so on will cause spikes in the mains voltage. A power spike or a power

surge is when the mains voltage jumps to well over 220 volts for a short

time. The mains voltage can also can dip below 220V, providing an

undervoltage supply. This can be caused by faults in the power network

and sharp load changes. This kind of condition is often seen in light

bulbs that dim in intensity, a condition known as brownout.

The mains supply can also be noisy when signals at frequencies other

than 50 Hz find their way onto the power lines.

Lastly, the supply can black out. In this case there is a total voltage loss

and all electrical equipment is left without power. Blackouts can last for

a few moments, or sometimes they can last for a number of days - a

common condition especially in the remote parts of the country.

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A UPS counters power disturbances in two ways:

By acting as a buffer between the sensitive studio equipment and the

fluctuating mains power supply, providing protection from power surges,

dips and line noise.

By providing back-up power in the event of a complete power failure.

The duration of the availability of back-up power is dependent on the

batteries used as part of the UPS.

Types of UPS

There are three main types of UPS: off-line, line interactive and online UPS.

Each one has different features:

1. Offline UPS

Off-line UPSs only supply equipment with back up power when the

mains supply is not available; and are generally used on equipment

which can accept a momentary loss of power.

Offline UPSs be used in conjunction with surge protection devices -

often known as spikeguards, which may be built into the power supply

points themselves. Offline UPSs provide no inherent protection from

spikes and brownouts, both of which can be dangerous for electronic

equipment. In this sense, they are most appropriate for areas with minimal

power problems, though they are the cheapest of the three types in

terms of cost.

Fig 34: Offline UPS system

2. Line interactive UPS

Line-interactive UPSs are used when mains voltage fluctuations (dips and

spikes) are a problem. Like the offline UPS, in the line-interactive system,

battery power is only utilized when the mains supply is not available. But in

addition, the mains power itself is fed to the equipment through a transformer;

and a monitoring circuit watches the main supply for dips and spikes.

Mains

Power

Inverter

Batt

Charger

Load

Switch

Battery

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Though line interactive UPSs respond to spikes and drops in voltage,

there is still a distinct response time within which the change in

voltage could affect your electronic devices.

Fig 35: Line interactive UPS

Thus, it is line interactive because it corrects the voltage, or switches to

backup power, based on a constant assessment of the mains supply.

Mains

Power Transformer

Battery

Inverter/

Charger

Load

3. Online UPS

The on-line UPS provides the greatest safety and the highest equipment

protection.

In the on-line UPS, mains power is converted to DC through a rectifier,

removing any chance of surges and dips. This is then converted through

an inverter to a completely back-up based AC supply. When mains

power fails completely, the system runs off the backup batteries.

Strictly speaking, these are the best UPSs for sensitive electronic

equipment - but they are the most expenive kind as well, often being

more than twice the cost of an offline UPS of similar rating.

Fig 36: Online UPS

UPS systems are only back up power supplies! Having a UPS system

is pointless if you have frequent interruptions of your mains power

supply, as the UPS batteries will only charge as long as it is plugged

into the mains supply

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Power rating and back up duration

There are two specifications for UPSs that you have to keep in mind beyond

the types specified above.

The first consideration is its power rating - that is, the maximum power

consumption that it can support. Each piece of equipment that you run off

any power supply will consume some power. The UPS you acquire must be

able to comfortably support all the equipment that you wish to connect to it.

UPS power ratings are usually given in Volt Amperes (VA) or Kilo-Volt

Amperes (KVA). Standard ratings include:

650 VA (about enough to support one computer with a 15" monitor)

1 KVA (enough for one computer with 15" monitors, along with a CD

player, 6 channel mixer, a cassette deck, studio audio monitors)

1.5 KVA (enough for two computers with 15" monitors, along with two CD

players, mixer, a cassette deck, powered studio monitors, amplifiers )

2 KVA (enough for all of the above, plus MD or flash based recorder units,

studio lights)

Large 5 KVA units and higher are used to back up entire offices.

A good rule of thumb is to get a UPS that can support about 30% more

than the maximum load that you will place on it. Another rule of

thumb for small and medium CR stations is to assume a minimum of

1.5 KVA per studio, not including transmission equipment and lights.

Inverter batteries are a consumable: Whether you use it or not, batteries

have a limited life based on the number of charge-discharge cycles

they can handle. You must therefore count on changing the UPS

batteries every two years or thereabouts.

Remember that old batteries can be returned to dealers in exchange

for a discount on the price of a fresh battery!

The second consideration is the amount of back up time that the UPS will

give you at the power rating it can support: This is dependent on the quality

and storage capacity of the batteries that the UPS system utilizes. In the

examples given above, the 650 VA UPS with a single battery can give about

15 minutes backup for the single computer it supports, with a simple two

wheeler automotive battery. But the 1.5 KVA UPS may be attached to two 25

plate truck batteries, and may give 3 - 4 hours backup for the entire load it

handles. UPSs can often be matched to a larger battery setup in order to

prolong the backup time.

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What kind of batteries?

Older battery technology involved the use of lead-acid batteries, which

remain the most easily available type of large rechargeable battery

anywhere in the country.

In lead acid batteries, the lead plates which form the cells of the battery

are bathed in sulphuric acid, which acts as the electrolyte, the charge

transporting chemical. In such batteries, it is important to maintain the

dilution of the acid at a specific level, which involves the topping up of

the liquid inside the battery with distilled water at regular intervals. The

distilled water is poured in through several rubber or plastic caps on the

top of the battery: Unscrewing the caps lets you access the insides of the

battery.

Though standard lead acid batteries are cheaper, and easy to obtain.,

an additional concern is that they should not be placed indoors or in

enclosed spaces, because the acid tends to give out fumes which are

harmful when breathed and corrosive to electronic equipment.

Modern rechargeable automotive and inverter batteries, however, are

maintenance free and need no topping up. They use a different

combination of chemicals to retain the charge; can be placed indoors;

and often last longer in regular use than the lead acid type (not least

because we often forget to top up the lead acid ones at the correct point

in time!). However, maintenance free batteries are much more expensive.

Nearly all major battery manufacturers provide both kinds of

batteries. Ask the UPS supplier which ones he recommends - in

most cases, he will be able to get you a good deal as a mass supply

agent. But remember to check the market price of the batteries he

suggests anyway!

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GENERATORS

In essence, a generator is the reverse of an electric motor: Where the motor

consumes electricity in order to move, the generator uses a fuel source in

order to move a magnet and generate electricity. Thus where a UPS simply

stores existing power, the generator manufactures power. This means

generators can be used in places where electricity supply is erratic - as long

as fuel is available.

Generators also work on the principle of electric induction: A motor running

on kerosene, diesel, petrol or LPG (Liquefied Petroleum Gas) is used to spin

a powerful magnet within a coil of conducting wire. The movement of the

magnetic field around the coil generates an electric current in the coil that

can then be drawn off, corrected ('rectified') and supplied to devices.

Portable generators nowadays come in a range of capacities. Like UPSs,

they are usually rated in VA or KVA (Volt Amperes or Kilo Volt Amperes).

650 VA, 1250 VA, 1600 VA and 2400 VA generally fall into the portable

category. These usually run off petrol, kerosene or LPG. Larger generators

(5 KVA, 10 KVA and so on) are usually run off diesel.

Like any other fuel driven motor - a car engine, say, or a grain thresher -

generator engines need regular maintenance. Their engine oil (which

lubricates the moving parts of the motor) needs to be replaced, the sparkplugs

(which ignite the fuel mixture in petrol, kerosene or LPG units) cleaned - and

the fuel filters and tanks serviced. The additional maintenance can be a

hassle for a small CR station; but weigh this against the potential need for

continuous electricity supplies.

Generators are most often used in situations where power cuts are a norm,

or where power supply can be seriously interrupted for a long period of

time. A CR station cannot broadcast only when the power permits! So though

a good generator from a reputed company may cost a lot initially to install,

it should be factored in during the planning process itself if power is a

potential logistical problem.

Generators generate high voltages and need cabling to be connected to the

power supply of the station. They also give out exhaust fumes from the

internal combustion process they use. This can represent a potential hazard

to the people who work there if the cables are poorly managed or the

generator is installed in a place where the fumes cannot be vented properly.

Follow a safety code when using generators, and ensure that everyone

knows and follows this code when starting or operating the generator.

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Many generators are also attached to changeover circuits which let you

connect the generator to the power supply in parallel to your existing mains

supply. These changeover circuits often come in the form of a box, and are

often built to automatically cut off the generator when the power comes

back, so that both supplies do not add up and fry your electronics.

The installation of the generator and the disconnect and transfer

switches MUST be performed by a qualified electrical contractor.

This is not a job for the station's technical department. Do not attempt

to install these devices yourself or make repairs without adequate

knowledge of the devices and eletricals!

Safety code for generator operation

1. NEVER run an electric generator inside a building.

2. ALWAYS store the generator fuel (petrol, kerosene or diesel) in

proper containers, in a safe and secure place.

3. NEVER fuel an electric generator while the generator is running!

4. DO NOT smoke or bring naked flames near the generator, or when

handling fuel.

5. ENSURE proper ventilation around the generator.

6. ALWAYS have a fully charged, approved fire extinguisher located

near the generator.

7. ALWAYS disconnect from the mains supply BEFORE starting your

backup generator. The generator should normally be installed so

that this happens automatically: That is, you should have a

changeover switch so the generator cuts off automatically when the

mains power comes back. (Otherwise the circuits will suddenly be

charged with 220 + 220 = 440 Volts of electricity, and everything

in your studio will be destroyed! Automatic changeovers are the

best choice, failing which one can manually switch the mains isolator

off. Manual switching requires discipline and a systematic approach

- we may sometimes not know when the power comes back and

use the generator unnecessarily. Besides, forgetfulness can be

disastrous.)

8. NEVER remove or tamper with safety devices - they are there to

protect you.

9. NEVER attempt to repair an electric generator yourself. ALWAYS

refer repairs to your supplier or other qualified serviceman.

10. Many engine parts are very HOT during operation. Don't touch

them as you could get severely burnt.

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Section C

Appendices

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APPENDIX 1

SUGGESTED SETUPS FOR CR STATIONS

On the next few pages, you will see some suggested combinations of

equipment for CR stations of varying scales and scope. The tables present

an outline ready-reckoner that you can use to work out a list that will suit

your purposes and your CR station. There are three different suggestions

India, and each is based on their individual experience and understanding

of the needs and imperatives of CR technology.

Remember that equipment models and technology change all the time: This

means the suggested models and prices indicated are subject to regular

revision. To get an up to date version of this table, you may have to spend

some time researching new models and prices.

Additionally, these are only suggested combinations of equipment. Ask

friends, professional acquaintances and colleagues from other CR stations

about their experiences with equipment – and for their recommendations

on what might work for your setup. Once you have a basic list of equipment,

get comparative estimates from a number of suppliers. Select the supplier

with the best reputation and the one who offers you a maintenance related

deal.

All prices and estimates included here are estimated street prices in India.

There may be huge variations between official billed prices from importers

and retail agents and the ‘grey’ (unofficial) market. Please treat these costs as

indicative only.

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S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

Studio Equipment 67000

1 Mixing Console, 1 mono mic 4/3 stereo line Behringer Eurorack 1 10000 10000 www.behringer.com

UB502

2 Microphone (dynamic) Shure SM 58 1 8000 8000 www.shure.com

3 Professional headphones Behringer HPM 1000 4 1000 4000 www.behringer.com

4 PC Computer as DAW - Intel Core 2 Duo 2.16/

512 MB RAM/160 GB HDD/Combo drive/

17" CRT monitor/Creative Audigy 256 Sound Assembled Mixed 1 45000 45000 —

card/Intel motherboard/ATX cabinet/Creative

speakers/Windows XP SP2

Field recording Equipment 81600

5 Microphone (condensor) Sony ECM MS 907 3 6000 18000 www.sony.com

6 Compact Digital field recorder Zoom H 2 4 15000 60000 www.zoom.co.jp

7 Memory (SD cards: 2 GB) Transcend Transcend SD 3 1200 3600 www.transcend.com

Transmission equipment 350000

8 50W VHF FM transmitter BEL LVB 206 1 — www.belindia.com

9 Dummy Load —

10 5/8 Vertical omni directional antenna Veronica 5/8S Vertical 1 — www.veronica.co.uk

(Contd...)

Suggested Setup 1A (Courtesy: N. Ramakrishnan, Ideosync Media Combine)

Setup IA: Basic Community Radio Station (digital)

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S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

11 RF Cable (RG 213) Various 50 m — Local manufacturers

12 Compressor limiter Behringer/ — www.behringer.com

D&R www.d-r.nl

Miscellaneous 60000

13 UPS system with maintenance free batteries Microtek 1250 VA 1 30000 30000 www.microtek.com

14 Guyed mast system/antenna tower — 15 m – 30m 1 20000 20000 Local fabrication

15 Miscellaneous connectors/cables+low cost

acoustic treatment — As reqd 15000 10000

TOTAL 558600 ~560000

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S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

Studio Equipment 192500

1 Mixing console 4/5 Mono 4/3 stereo line Yamaha MG 12/4 1 20000 20000 www.yamaha-mg.com

2 Microphone, condensor 1" capsule Behringer TSM 87 2 6500 13000 www.behringer.com

3 Microphone (dynamic) Shure SM 58 2 8000 16000 www.shure.com

4 Professional headphones Behringer HPM 1000 5 1000 5000 www.behringer.com

5 Studio Monitors Behringer Truth B 2031 1 15000 15000 www.behringer.com

6 4-way headphone amplifier Alto Pro — 1 9000 9000 www.altoproaudio.com

7 Telephone hybrid D & R TH 1 1 22000 22000 www.d-r.nl

8 Sound card M-Audio Revolution 7.1 1 7500 7500 www.m-audio.com

9 4 way line box Behringer Ultra Di-pro 1 8000 8000 www.behringer.com

10 Mic stands Proel — 4 2500 10000 www.proelgroup.com

11 100 m Shielded audio cable with 30 pieces Proel — Set 10000 10000 www.proelgroup.com

each of XLR female & male, and 30 pieces RCA

12 Studio Compressor Limiter Alto Pro 2 channel 1 12000 12000 www.altoproaudio.com

13 PC Computer as DAW - Intel Core 2 Duo 2.16/ Assembled Mixed 1 45000 45000 —

1 GB RAM/160 GB HDD/Combo drive/

17" CRT monitor/M-audio Sound card/Intel

motherboard/ATX cabinet/ /Windows XP SP2

(Contd...)

Suggested Setup 1B (Courtesy: N.Ramakrishnan, Ideosync Media Combine)

Setup IB: Middle level Community Radio Station (digital)

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Field Recording Equipment 133200

14 Microphone (condensor) Sony ECM MS 907 6 6000 36000 www.sony.com

15 Compact Digital field recorder Zoom H 2 6 15000 90000 www.zoom.co.jp

16 Memory (SD cards: 2 GB) Transcend Transcend SD 6 1200 7200 www.transcend.com

Transmission Equipment 450000

17 50W VHF FM transmitter BEL LVB 206 1 — www.belindia.com

18 Dummy Load —

19 Stacked dipole antenna Veronica Stacked dipole 1 — www.veronica.co.uk

20 RF Cable (RG 213) Various 50 m — Local manufacturers

21 Compressor limiter Behringer/ — www.behringer.com

D&R www.d-r.nl

Miscellaneous 165000

22 UPS system with maintenance free batt Nexus/Microtek 1250 VA 1 30000 30000 www.microtek.com

23 Guyed mast system/antenna tower — 15 m – 30m 1 20000 20000

24 Generator Honda Siel EXK 2000 S 1 60000 60000

25 Carpentry + office furniture + racks Miscellaneous — Set 30000 30000

26 Office computer system Intel Core 2 Duo Assembled — — 25000 25000

2.16/256 MB RAM/120 GB HDD/Combo

drive/15" CRT monitor/ Intel motherboard/

ATX cabinet/Windows XP SP2

Total 940700 ~ 950000

S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

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(Contd...)

Suggested Setup 1C (Courtesy N.Ramakrishnan, Ideosync Media Combine)

Setup III: Large Community Radio Station (digital)

S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

On air studio Equipment 572500

1 On AIR mixer/4-2-6 control room/studio AEQ BC-500 1 300000 300000 www.aeqbroadcast.com

monitoring

2 Rode Condensor Studio Microphone Rode NT 1A 4 18000 72000 www.rodemic.com

3 CD player Denon DNC 630F 1 10000 10000 www.denon.com

4 Double tape deck Denon DN770R 1 10000 10000 www.denon.com

5 Telephone Hybrid Telos Telos 1 2 32000 64000 www.telos-systems.com

6 Mic stands Proel ST232, 23850 4 1500 6000 www.proelgroup.com

7 Professional headphones Behringer HPM 1000 6 1000 6000 www.behringer.com

8 Headphones Amplifier Behringer HA 8000 1 9000 9000 www.behringer.com

9 Studio & Control Room Monitors (Pair) Behringer Truth B2031 1 (pair) 22000 22000 www.behringer.com

10 Patch Bay Neutrik — 2 6500 13000 www.neutrik.com

11 Patch Cords Proel — 24 250 6000 www.proelgroup.com

12 19" rack Proel — 2 10000 20000 www.proelgroup.com

13 Assorted studio cables/Multi cable/Plugs Proel — Set 20000 20000 www.proelgroup.com

14 UPS 1250 VA double battery El Nova — 1 3500 3500 www.elnova.com

15 Studio Compressor Limiter Alto Pro 2 channel 1 12000 12000 www.altoproaudio.com

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(Contd...)

Production studio Equipment 392500

1 Production Digital Mixer Yamaha 01V96 1 165000 165000 www.yamaha.com

2 Rode Condensor Studio Microphone Rode NT 1A 2 18000 36000 www.rodemic.com

3 CD player Denon DNC 630F 1 10000 10000 www.denon.com

4 Double tape deck Denon DN770R 1 10000 10000 www.denon.com

5 Telephone Hybrid Telos Telos 1 1 32000 32000 www.telos-systems.com

6 Mic stands Proel ST232, 23850 2 1500 3000 www.proelgroup.com

7 Professional headphones Behringer HPM 1000 2 1000 2000 www.behringer.com

8 Studio & Control Room Monitors (Pair) Behringer Truth B2031 1 (pair) 22000 22000 www.behringer.com

9 Patch Bay Neutrik — 2 6500 13000 www.neutrik.com

10 Patch Cords Proel — 24 250 6000 www.proelgroup.com

11 19" rack Proel — 2 10000 20000 www.proelgroup.com

12 Assorted studio cables/Multi cable/Plugs Proel — Set 20000 20000 www.proelgroup.com

13 UPS 1250 VA double battery El Nova — 1 3500 3500 www.elnova.com

14 PC Computer as DAW - Intel Core 2 Duo 2.16/ Assembled Mixed 1 50000 50000 —

1 GB RAM/160 GB HDD/Combo drive/17"

CRT monitor/M-audio Sound card/Intel

motherboard/ATX cabinet/ /Windows XP SP2

S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

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S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

Field Recording Equipment 177600

1 Microphone (condensor) Sony ECM MS 907 8 6000 48000 www.sony.com

2 Compact Digital field recorder Zoom H 2 8 15000 120000 www.zoom.co.jp

3 Memory (SD cards: 2 GB) Transcend Transcend SD 8 1200 9600 www.transcend.com

Audio Editing Setup ( 3 editing systems) 159600

1 PC Computer - Intel Core 2 Duo 2.16/1 GB Assembled — 3 45000 135000 —

RAM/160 GB HDD/Combo drive/17" CRT

monitor/Creative Audigy 256 sound card/Intel

motherboard/ATX cabinet/ /Windows XP SP2

2 UPS 650 VA double battery El Nova — 3 2700 8100 www.elnova.com

3 Speaker units for editing units Creative SBS 380 3 4500 13500 www.creative.com

4 Headphones for editing units Behringer HPM 1000 3 1000 3000 www.behringer.com

Transmission equipment 450000

1 50W VHF FM transmitter BEL LVB 206 1 — www.belindia.com

2 Dummy Load —

3 Stacked dipole antenna Veronica Stacked dipole 1 — www.veronica.co.uk

4 RF Cable (RG 213) Various 50 m — Local manufacturers

5 Transmission Compressor limiter Behringer/ 1 — www.behringer.com

D&R www.d-r.nl

(Contd...)

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Office Equipment 143600

1 Office computer systems Intel Core 2 Duo 1.83/ Assembled — 3 25000 75000

256 MB RAM/120 GB HDD/Combo drive/15"

CRT monitor/ Intel motherboard/ATX cabinet/

Windows XP SP2

2 Carpentry + office furniture + racks Miscellaneous — Set 40000 40000

3 UPS 650 VA double battery El Nova — 3 2700 8100 www.elnova.com

4 Fax machine Canon — 1 7500 7500 www.canon.com

5 Flatbed Scanner Canon — 1 5000 5000 www.canon.com

6 Telephone connection + Internet Installation — 1 3000 3000 —

7 Network hub + cabling Micronet — 1 5000 5000 www.micronet.info

Miscellaneous 170000

1 Generator 5 KVA soundproof Greaves 5 KVA 1 150000 150000

2 Guyed mast system/antenna tower — 15 m – 30m 1 20000 20000 Local manufacturers

Total 2065800 ~ 2066000

S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

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S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

Studio Equipment 62000

1 Mixing Console, 1 mono mic 4/3 stereo line Behringer Eurorack 1 10000 10000 www.behringer.com

UB502

2 Microphone (Condensor) Behringer C-1 1 6000 6000 www.behringer.com

3 Professional headphones Behringer HPM 1000 2 1000 2000 www.behringer.com

4 PC Computer as DAW - Intel Core 2 Duo 2.16/ Assembled Mixed 1 20000 20000 —

512 MB RAM/160 GB HDD/Combo drive/17"

CRT monitor/Creative Audigy 256 Sound card/

Intel motherboard/ATX cabinet/Creative

speakers/Windows XP SP2

5 External Hard Drive (500 GB) Toshiba, any 1 8000 8000

other

6 Sound proofing basic Local Using foam, 10000 10000

resources and heavy

curtains (for

roughly a

10x10 room)

7 Studio amp and monitoring speakers Local Local 6000 6000

Resources resources

Suggested Setup 2 (Courtesy Ramnath Bhatt, VOICES - with additional inputs from Abhijit Shylanath, consultant)

Setup II: Basic Community Radio Station (digital)

(Contd...)

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S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

Field recording Equipment 32000

8 Microphone (condensor) Sony ECM MS 907 2 6000 12000 www.sony.com

9 Compact Digital field recorder Sony IC Recorder 2 10000 20000 www.sony.com

Transmission equipment 190000

10 50W VHF FM transmitter WEBEL 1 — ww.webel-india.com

11 100/200 watt VHF antenna —

12 RF Cable (RG 213 or 7/8) Various 50 m —

Miscellaneous 40000

13 UPS system with maintenance free batteries Microtek 1250 VA 1 30000 30000 www.microtek.com

14 Guyed mast system/antenna tower — 15 m – 30m 1 Private — —

(If this can be obtained through private telecom telecom/

operator) BSNL

15 Miscellaneous connectors/cables — As reqd 15000 10000

Total 324000

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S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

Studio Equipment 72000

1 Mixing Console, 1 mono mic 4/3 stereo line Behringer Eurorack 1 10000 10000 www.behringer.com

Yamaha UB502 www.yamaha-mg.com

Mackie www.mackie.com

2 Microphone (dynamic) Shure SM 58 2 2000 6000 www.shure.com

Studio B2 3000 www.studioprojects.com

Projects

Sennheiser www.sennheiser.com

3 Professional headphones Behringer HPM 1000 4 1000 4000 www.behringer.com

Sony MDR- V150 1250 www.sony.com

4 C Computer as DAW - Intel Core 2 Duo 2.16/ Assembled Mixed 1 45000 45000

512 MB RAM/160 GB HDD/Combo drive/

17" CRT monitor/Creative Audigy 256 Sound

card/Intel motherboard/ATX cabinet/Creative

speakers/Windows XP SP2

5 DVD / CD player 2 3500 7000

Suggested Setup 3 (Courtesy: Ashish Bhatnagar, Prasar Bharti)

Very Basic Community Radio Station (digital)

(Contd...)

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S.No. Equipment Description Brand Model Quantity Approx. Total Internet resource

Price

Field recording Equipment 18000

6 Compact Digital field recorder Cenix With external 3 3500/ 18000

Edirol R1 mic 6000 www.edirol.net

Zoom H1 www.zoom.co.jp

Sony USB Rec www.sony.com

Transmission equipment 190000

8 50W VHF FM transmitter WEBEL 1 — www.webel-india.com

10 100/200 watt VHF antenna —

11 RF Cable (RG 213 or 7/8) Various 50 m — Local manufacturers

Miscellaneous

13 Inverter/ UPS with maintenance free batteries Microtek 600 VA 1 15000 15000 www.microtek.com

(150 AH)

14 Guyed mast system/antenna tower — 15 m – 30m 1 20000 20000

15 Miscellaneous connectors/cables — As reqd 15000 15000

+ low cost acoustic treatment

16. Misc. (wiring /furniture/ earthing etc) 50000 50000

Total 380000

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APPENDIX 2

AUDIO & RADIO EQUIPMENT MANUFACTURERS

(GLOBAL LIST)

The list below contains the details of the principal audio equipment

manufacturers globally, sorted by the type of equipment they specialize in.

Additional specifications and descriptions of the models of equipment they

manufacture are available at their respective websites.

1. Mixing consoles

www.altoproaudio.com Alto Standard Allround

www.behringer.com Behringer Standard Allround

www.alesis.com Alesis Standard Allround

www.mackie.com Mackie/Onyx Standard Allround

www.behringer.com Soundcraft Professional On Air and

Production

www.aeq.es AEQ Professional On Air and

Production

www.commsandsound.com Alice Professional On Air and

Production

www.d-r.nl D&R Professional On Air and

Production

www.sonifex.com Sonifex PProfessional On Air and

Production

www.wheatstone.com Audioarts Professional On Air and

Production

www.autogram-crl.com Autogram Professional On Air and

Production

www.arrakis-systems.com Arrakis Professional On Air and

Production

www.studer.ch Studer Professional On Air and

Production

www.yamaha.com Yamaha Professional On Air and

Production with PC

Multitrack control 200

www.fostex.com Fostex Production mixer and 4-8

Track digital recorder

www.tascam.com Tascam Standard all round,

Production with PC

Multitrack control 200

www.roland.com Roland Production mixer and 4-8

Track digital recorder

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www.axeldigital.com Axel Tech Mixer semi and Pro

www.aev.net AEV Professional On Air and

Production

www.axeltechnology.ru Oxygen 4 Professional On Air and

Production

www.klotzdigital.com Vadis/ Professional On Air - and

D.Cennium Production

2. Monitor Loudspeakers

www.behringer.com Behringer Studio, OB, PC

www.jbl.com JBL Studio, OB, PC

www.fostex.com Fostex Studio, OB, PC

www.yamaha.com Yamaha Studio, OB, PC

www.mackie.com Mackie Studio, OB, PC

www.creative.com Creative PC

www.tannoy.com Tannoy Studio, OB, PC

www.m-audio.com M-Audio Studio, OB, PC

www.krksys.com KRK Studio, OB, PC

www.tapcoworld.com Tapco Studio, OB, PC

www.genelec.com Genelec Studio,OB, PC

3. PA Systems

www.califone.com Califone 30 watt highly mobile

very small "one box"

www.bswusa.com Mackie Mixer, speakers, 1200

watts, 4 mic, stands,

cables

www.fender.com Fender Portable sound systems

12 volt

www.fender.com Fender 12 volt battery pack

based

www.proelgroup.com Proel PA Live

www.fbt.uk.com FBT PA Live

www.bswusa.com JBL JBL speakers, Soundcraft

mixer, AKG Mics

www.ahujaradios.com Ahuja PA systems, mics,

amplifiers for PA

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4. Telephone Hybrids

www.d-r.nl D&R Passive analogue and

digital

www.telos.com Telos Analogue and digital

www.sonifex.com Sonifex Analogue and digital

www.comconindustries.com Comcon Analogue

www.jk-audio.com JK Audio Digital

5. Microphones

www.akg.com AKG All types

www.shure.com Shure Dynamic, Electret

condenser

www.rode.com Rode Condenser Large

diaphragm

www.behringer.com Behringer Condenser, Dynamic

www.audiotechnica.com Audio Technica All types

www.sennheiser.com Sennheiser All types

www.electrovoice.com Electrovoice Dynamic, Electret

condenser

www.sony.com Sony Dynamic, Electret

condenser

www.heilsound.com Heil Dynamic, Condensor

www.studioprojectsusa.com Studio Projects Condensor

www.neumann.com Neumann Condensor, Dynamic

www.coleselectroacoustics Coles Ribbon commentator

.com Electroacoustics mics

www.beyerdynamic.de Beyer Dynamic, Electret

condenser

6. Headphones

www.akg.com AKG

www.sennheiser.com Sennheiser

www.denon.com Denon

www.sony.com Sony

www.behringer.com Behringer

www.koss.com Koss

www.beyerdynamic.de Beyer Dynamics

www.shure.com Shure

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7. Processors, Compressors and Limiters

www.behringer.com Behringer

www.tcelectronics.com TC Electronics

www.altoproaudio.com Alto Pro Audio

www.innovonics.com.au Innovonics

www.ramseykits.com Ramsey

www.veronica.co.uk Veronica

www.orban.com Orban

8. Computers (Branded)

www.apple.com Apple Macintosh OS based

Computers systems

www.dell.com Dell Corp. Windows OS based

systems

www.hp.com Hewlett Packard Windows OS based

systems / servers

www.compaq.com Compaq Corp. Windows OS

based systems

www.creative.com Creative Windows OS based

systems

www.lenovo.com Lenovo Windows OS based

systems, servers

www.asus.com Asus Tech Windows OS based

systems

www.msicomputer.com MSI Windows OS based

systems

www.acer.com Acer Windows OS based

systems

9. DVD,CD, MD, DAT, Cassette tape Player / Recorders

www.sony.com Sony CD, Minidisc, DAT

Cassette

www.d-mproasia.com Denon CD, Minidisc, DAT,

Cassette

www.tascam.com Tascam CD, Minidisc, DAT,

Cassette

www.panasonic.com Panasonic CD, DAT

www.fostex.com Fostex CD, Minidisc, Dat,

Cassette

www.superscope- Superscope CD, Casette

marantzpro.com

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10. Reel to reel 1/4" tape recorders

www.studer.ch Studer

www.revox.com Revox

www.akai.com Akai

www.tascam.com Tascam

11. Turntables

www.stantondj.com Stanton Analogue with stylus

www.denon.com Denon Analogue and Digital

output, with stylus

www.panasonic.com Technics Analogue with stylus,

instant start

12. Digital Portable & Studio Recorders

www.maycom.nl Maycom Flash recorders

www.marantz.com Marantz FlashDisc

www.hhb.co.uk HHB DAT, Minidisc. HDD and

flash recorders

www.fostex.com Fostex Muiltitrack

www.sony.com Sony Minidisc, flash recorders

www.sharpusa.com Sharp Minidisc

www.zoom.co.jp Zoom Flash recorders

www.motu.com Mark of the HDD recorders

Unicorn and processing

hardware

www.nagraaudio.com Nagra Hi-quality pro recorders

www.edirol.net Edirol Professional flash field

recorder units

www.aeq.es AEQ Portable flash field

recorder

www.hhb.co.uk HHB Microphone with

integrated flash recorder

www.sonifex.co.uk Sonifex PCM CIR HD

13. Operating systems and basic PC

www.microsoft.com Microsoft Windows OS (XP, Vista)

www.apple.com Apple OS Apple OS 10.5

www.linux.com LINUX Links to Linux based OS

variants

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14. Broadcast Software

www.winamp.com Winamp Sound playback,

conversion, Play list (free)

www.radiohost.com Radiohost On Air playout

automation

www.jazler.com Jazler On Air playout

automation

www.audioenhance Audioenhance On Air playout

automation(Non

commercial special price)

www.bdcast.com Broadcast On Air playout

Electronics automation

www.arrakis-systems.com Arrakis On air playout

automation (Some down

loads are free)

www.creamware.com Creamware On air playout

automation

www.bsiusa.com Simian On air playout

automation

www.aeqbroadcast.com AEQ On air playout

automation

www.studer.ch Studer On air playout automation

linked to Studer hardware

www.dalet.com Dalet On air playout automation

www.rcsuk.com RCS On air playout automation

www.enco.com ENCO On air playout automation

www.echolab.com Echolab Professional automation

Conductor

15. Sound edit and processing software

www.steinberg.net Steinberg Cubase, Nuendo software

www.digidesign.com Digi Design Pro Tools

www.adobe.com Adobe Audition software

www.cakewalk.com Cakewalk Cakewalk software

www.sourceforge.net Audacity Audacity (Free)

www.wavosaur.com Wavosaur Wavosaur (Free)

www.baxtrom.com Soliton Soliton 2 (Free)

www.sonycreative Sony Creative Soundforge

software.com

www.nero.com Nero Nero Wave Editor

(Bundled with CD

burner)

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16. Soundcards

www.soundblaster.com Creative

www.terratec.com Terratec

www.creamware.com Creamware

www.steinberg.net Steinberg

www.rme.com RME

www.digigram.com Digigram

www.yamaha.com Yamaha

www.turtlebeach.com Turtle Beach

www.motu.com Mark of the Unicorn

17. XLR Plugs, cables and patch bays

www.proelgroup.com Proel

www.neutrik.com Neutrik

www.switchcraft.com Switchcraft

www.deltron-emcon.com Deltron

18. Microphone stands

www.proelproaudio.com Proel

www.k-m.de Konig Meyer

www.ahujaradio.com Ahuja

19. FM Transmitters

www.ramseykits.com Ramsey Kits Low Power and building

kits, low cost.

www.itelcast.com Itel All types, low to medium

cost transmitters

www.dbbroadcast.com DB Elettronica All types, low to medium

cost transmitters

www.rvrusa.com RVR All types, low to medium

cost transmitters

www.crownbroadcast.com Crown Low - medium

Broadcast power. Plug and Play

transmitters

www.telefunken.com Telefunken All powers, Analogue

and Digital, Expensive

Pro.

www.martielectronics.com Marti Plug and Play

transmitters;

STL Link systems

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www.broadcast BE Heavy duty medium and

electronics.com High power Transmitters.

www.bext.com Bext Corp. All types, low to medium

cost Transmitters

www.rohde-schwarz.com/ Rohde Schwartz All powers, Analogue

and Digital, Expensive

Pro

www.veronica.co.uk Veronica Co. Low power, Low cost.

www.pcs-electronics.com PCS Electronics FM PCI card

www.sbsfm SBS Medium cost transmitters

www.webelmediatronics.in Webel Low cost Indian

transmitters

www.bel-india.com BEL Low cost Indian

transmitters

www.nautel.com Nautel All types of transmitters,

including digital radio

www.audemat-aztec.com Audemat-Aztec All types of transmitters,

including digital radio

www.harris.com Harris Corp. High End transmitters

20. FM Transmitting Antennas

www.ramseykits.com Ramsey Kits Building instructions for

"do it yourself people"

www.aldena.tv Aldena Low to medium power,

medium cost

www.itelcast.com Itel Low to medium power,

medium cost

www.armstrongtx.com Armstrong Low to High Power

www.dbbroadcast.com DB Elettronica Low to medium power,

medium cost

www.vhfteknik.se VHF Teknik Low to medium power,

medium cost

www.andrew.com Andrew Low to High

Corporation Power

www.dielectric.com Dielectric Low to High Power

www.rfsworld.com RFS Low to High Power, all

types

www.radiostructures.co.uk Radio Structures Various low power

Ltd.

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21. Masts and towers

www.clarkmasts.com Clark Masts Pump up masts for mobile

Teksam Ltd. use

www.racal-antennas.com Racal Antennas Pump-up

www.radiostructures.co.uk Radio Different wind- and pump-

Structures Ltd. up masts

22. Satellite Receivers

www.worldspace.com WorldSpace Digital reception

equipment (needs

subscription)

23. Cases and furniture

www.proelgroup.com Carry cases, packs

www.skbcases.com Airtight, Waterproof: Foam/

ABS/stainless steel

www.portabrace.com World leading designer of

blue nylon cases

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APPENDIX 3

LIST OF ADVISORY ORGANIZATIONS & INDIVIDUALS

Beyond the basic information contained within this manual, and the

information you may be able to research on your own, there are several

individuals and organizations that you can contact for additional information,

advice or assistance in setting up your own community radio station.

This list gives the names and contact details of several of these organizations

and individuals. Please note that though their primary office locations are in

specific cities, many of these agencies and advisers have experience working

across the entire country.

Note: This is not a list of funding organizations!

Community Radio setup, community mobilization, content

and technical training, setup

1. United Nations Educational Scientific & Cultural

Organization (UNESCO)

Address: UNESCO House, B-5/29, Safdarjung Enclave, New Delhi 110029

Telephone: +91-011-36713000

Telfax: +91-11-26713001/02

Web: www.unesco.org/delhi

Email: newdelhi@unesco.org

2. United Nations Children’s Fund (UNICEF)

Address: India Country Office, UNICEF House, 73, Lodhi Estate,

New Delhi - 110003

Telephone: +91-011-24690401

Telfax: +91-11-24691410/24627521

Web: www.unicef.org/india

Email: smukherji@unicef.org (Supriya Mukherji, Programme

Communications Officer)

3. United Nations Development Fund (UNDP)

Address: India Country Office, 55, Lodhi Estate, New Delhi – 110 003

Telephone: +91-011-24628877

Telfax: +91-11-46532333, 24627612

Web: www.undp.org.in

Email: john.borgoyary@undp.org (John Borgoyary, Programme Officer)

4. Community Radio Forum - India (CRF)

Address: C/o Drishti Media Collective, 103, Anand Hari Tower, New Sandesh

Press Road, Opp. Chanakya Tower, Bodakdev, Ahmedabad ,

Gujarat - 380 054

Telephone: +91-79-26851235, 66614235

Web: www.drishtimedia.org

Email: stalink123@gmail.com (K.Stalin, Convenor)

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5. Ideosync Media Combine

Address: 177, Ashoka Enclave III, Sector 35, Faridabad – 121 003 – Haryana

Telephone: +91-0129-4131883, 6510156 (Prefix 95129-from Delhi)

Telfax: +91-0129-2254395 (Prefix 95129- from Delhi)

Web: www.ideosyncmedia.org

Email: info@ideosyncmedia.org

6. Panos Institute South Asia (India Country Office)

Address: D-302, 2nd Floor, Defence Colony, New Delhi - 110024

Telephone: +91-011-24615217, 24615219

Fax: +91-011-24615218

Web: www.panossouthasia.org/india

Email: panos@panosindia.org

7. Mysore Resettlement and Development Agency (MYRADA)

Address: No.2, Service Road, Domlur Layout, Bangalore 560071, Karnataka

Telephone: +91-080-25352028/3166

Fax: +91- 080-25350982

Web: www.myrada.org

Email: myrada@vsnl.com

8. Alternative for India Development (AID India)

Address: Plot No.1 V.G.N. Nagar, Iyyapanthangal, Chennai - 600 056 -

Tamil Nadu

Telephone: +91-044-26272336, 26490014

Fax: +91-044-26272340

Web: www.aidindia.net

Email: aidindia1@vsnl.com

9. Drishti Media Collective

Address: 103, Anand Hari Tower, New Sandesh Press Road,

Opp. Chanakya Tower, Bodakdev, Ahmedabad - 380 054 - Gujarat

Telephone: +91-79-26851235, 66614235

Web: www.drishtimedia.org

Email: drishtiad1@gmail.com

10. Deccan Development Society (DDS)

Address: 101, Kishan Residency, 1-11-242/1, Street No. 5, Shyamlal Buildings

Area, Begumpet, Hyderabad - 500 016 – Andhra Pradesh

Telephone: +91-040-27764577, 27764744

Telfax: +91-040-27764722

Web: www.ddsindia.com

Email: hyd1_ddshyd@sancharnet.in, hyd2_ddsppvr1@sancharnet.in,

ddshyderabad@gmail.com

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11. VOICES

Address: No. 165, First Floor, 9th Cross, Indiranagar Ist Stage, Bangalore-

560038 - Karnataka

Telephone: +91-080-25213902, 25213903

Fax: +91-080-25213901

Web: www.voicesindia.org, www.voices4all.org

Email: ram@voicesindia.org (Ramnath Bhatt)

12. One World South Asia (OWSA)

Address: C-5 Qutab Institutional Area, New Delhi – 110016

Telephone: +91-011-41689000

Fax: +91-011-41689001

Web: http://southasia.oneworld.net

Email: southasia@oneworld.net

13. Commonwealth Educational Media Center for Asia

(CEMCA)

Address: C-5/4, Safderjung Development Area, New Delhi – 110016

Telephone: +91-011-26537146

Fax: +91-011-26537147

Web: www.cemca.org

Email: r.sreedher@gmail.com (Dr.R.Sreedher, Director)

14. Mahila Samakhya, Karnataka (MSK)

Address: No 68, 1st Cross, 2nd Main, HAL 3rd Stage, Near New Thippasandra

Main Road, Bangalore 560 075, Karnataka, India

Telephone: +91-80-25727471, 25262988

Web: www.mahilasamakhyakarnataka.com (under construction)

Email: samakhya@vsnl.net

15. Mandaakini Ki Awaaz Samudayik Radio

Address: Kendra Bhanaj, P.O. Machkandi via Chandrapuri, Tehsil Ukhimath,

Distt. Rudraprayag, Uttarakhand - 246 425

Telephone: +91-01364-213114, 9411389062

16. Hevalvaani Samudayik Radio

Address: Kendra Chamba, Mussoorie Road, Chamba, Distt. Tehri Garhwal,

Uttarakhand - 249145

Telephone: +91-01376-256159

17. DHAN Foundation

Address: 18, Pillaiyar Koil Street, S.S. Colony, Madurai - 625 016 - TamilNadu

Telephone: +91-0452-2610794, 2610805

Fax: +91-0452-2602247

Web: www.dhan.org

Email: dhan@md3.vsnl.net.in

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18. Digital Empowerment Foundation

Address: D-307, 1st Floor, Sarvodaya Enclave, New Delhi – 110 017

Telephone: +91-11-51829729

Web: www.defindia.org

Email: osama_manzar@yahoo.com (Osama Manzar)

19. Knowledge Networking for Rural Development in Asia/

Pacific Region (ENRAP)

Address: IDRC Regional Office for South Asia, 208, Jor Bagh,

New Delhi 110003

Telephone: +91-11-24619411 (Ext. 102)

Fax: +91-11-24622707

Web: www.nomadindia.net

Email: michelle@nomadindia.net (Michelle Chawla)

20. Nomad India

Address: 1, Sapote building, Irani Road, Dahanu – 401602 – Maharashtra

Telephone: +91-02528-222241, 9860030888/9890150999

Fax: None

Web: www.nomadindia.net

Email: michelle@nomadindia.net (Michelle Chawla)

21. Kutch Mahila Vikas Sangathan (KMVS)

Address: Media Cell, C/o Kutch Mahila Vikas Sangathan, 15-A, “Midhara”,

Himmat Nagar, Revenue Colony, Bhuj - 370 001 - Kutch District,

Gujarat

Telephone: +91-02832-222124, 223311

Email: ujjasradio@gmail.com, preetikutch@yahoo.co.in

22. Auroville Radio

Address: Auroville Radio – TV, Town Hall Complex, Auroville – 605101

- Tamil Nadu

Telephone: +91- 0413-2622250, 2622170

Fax: +91-0413-2622055

Web: www.aurovilleradio.org

Email: info@aurovilleradio.org (Andrea Tazzarri)

23. Anna FM 90.4, Chennai

Address: C/o EMRC, Anna University, Guindy, Chennai - 600025

Telephone: +91-044-22300106

Telefax: +91-044-22300105

Web: http://collinfo.annauniv.edu:6060/emrc/annafm/annafm.htm

Email: p_lakshmi@annuniv.edu (Dr.P.Lakshmi, Director-in-charge, EMRC)

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24. IT for Change

Address: No.393, 17th Main, Jayanagar 4th ‘T’ Block, Bangalore - 560041 -

Karnataka

Telephone: +91-080-26654134, 26536890

Fax: +91-080-41461055

Web: www.ITforChange.net

Email: itfc@ITforChange.net

25. Charkha

Address: Ground Floor, G-15/11-12, G - Block, Malviya Nagar,

New Delhi – 110 017

Telephone: + 91-11-26680688, 26680816

telfax: +91-11-26680816

Web: www.charkha.org

Email: charkha@bol.net.in

26. Aga Khan Foundation

Address: Sarojini House II Floor, 6 Bhagwan Dass Road,

New Delhi -110001

Telephone: +91-011-23782173

Fax: +91-011-23782174

Web: www.akdn.org/india

Email: general@akfindia.org

27. World Development Foundation (WDF)

Address: Plot 5, Sector 3, Karuna Kunj, Dwarka (Behind DPS, in front of

BSES), New Delhi – 110 075

Telephone: +91-011-25082764

Telfax: +91-011-25082764

Web: www.wdfindia.org

Email: mail@wdfindia.org

Independent Consultants

1. Ashish Bhatnagar (Technical) (Honorary Advisor)

Address: 313, Asia House, Kasturba Gandhi Marg, New Delhi - 110001

Telephone: +91-011-23073881

Mobile: +91-9868183881

Email: abroadcaster@gmail.com

2. Jean Parker (Content Creation & Recording)

Address: A703 Supreme Green Woods, NIBM Road., Kondhwa,

Pune - 411048 - Maharashtra

Telephone: +91-020-4005582

Mobile: +91-9890436033

Email: radioforever@gmail.com

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3. Mahesh Acharya (Technical)

Address: No.307. B Block, Manjunatha Residency,

Opp. SCT College, Vigyan Nagar, Bangalore - 560 075 -

Karnataka

Telephone: +91-80-41709551

Mobile: +91-9886303077

Email:mahesh.aacharya@gmail.com. cr_4_agriculture@yahoo.com

4. Dr. Arun Mehta (Technical)

Address: B-69, Lajpat Nagar - I, New Delhi-110024

Telephone: +91-011-29817007

Email: arun.mehta@gmail.com

5. Vickram Crishna (Technical)

Address: A31/32 Queens Apts, Pali Hill, Bandra, Mumbai – 400050 -

Maharashtra

Telephone: (Available on request)

Email: vvcrishna@radiophony.com

Web: www.radiophony.com

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APPENDIX 4

AUDIO & RADIO EQUIPMENT VENDORS IN INDIA

The list below contains the details of the key suppliers and vendors of audio

and radio related equipment in India. This is by no means an exhaustive list,

and is based on the agencies and vendors that many people who have

participated in the development of this manual have recommended. This

should provide you a starting point for your enquiries when you begin the

process of acquiring equipment.

A. Acoustics & Studio setup consultants

Broadcast Engineering Consultants India Ltd. (BECIL)

14-B, Ring Road, I.P. Estate,

New Delhi 110002

Tel: +91-11-23378823

Fax: +91-11-23379885

E-Mail: becil@vsnl.com

Web: www.becil.com

Technomedia Solutions Pvt. Ltd.

1001, Kailash Building

26, Kasturba Gandhi Marg

New Delhi 110001, INDIA

Tel: +91-11-23765169/70/7

Fax: +91-11-23765152

E-Mail: kc@technomediaindia.com, s.nigam@technomediaindia.com

Web: www.technomediaindia.com

All India Radio (AIR) Resources Unit

DG, AIR, Akashwani Bhawan

Parliament Street, New Delhi - 110001

Tel: +91-11-23421187, 23421221

E-Mail: ismehla@air.org.in, neeraj@air.org.in

Web: www.resourcesair.com

Noori Broadcast Solutions Pvt. Ltd.

99-National Park,

Lajpat Nagar-IV,

New Delhi-110024 (India)

Tel: +91-11-65636876

Mob: +91-9811983404, 98891070243

Fax : +91-11-65636876

E-Mail: akhtarma@yahoo.com

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Electro Dynamics

58/46, Birhana Road

Kanpur 208 001.

Tel: +91-11-41622014

Fax: +91-11-26430947

E-Mail: eledyne@vsnl.net

Rivera International

397/A, Mangaldas House,

Naaz Cinema Compound Lamington Road, Mumbai 400 004

Tel: +91-22-2200555/777

Fax: : +91-22-23862342

E-Mail: anam@bom2.vsnl.net.in

B. Multi-equipment providers

Advanced Telemedia Pvt. Ltd.

12 A Kalkaji

New Delhi -110019

Tel: +91-11-41675452-4

Fax: +91-11-41675451

Email: sales@atmpl.com

Web: www.atmpl.com

Falcon Technologies

102 Empire Apartments

98 M. G. Road, Sultan Pur

New Delhi 110 030

Tel: +91-11-26804631, 32 / 26804640, 51

Fax: +91-11-26806966

E-Mail: falcontech@eagle-grp.com

Trimurti Instruments

13, Sopariwala house No. 5,

1st floor, Chunam lane,

Lamington Road,

Mumbai - 400007 - Maharashtra.

Tel: +91-22-23858704, 25379253

Mob: +91-9869164174

Email: pankajath@gmail.com, pankajath@hotmail.com

Shaf Broadcast Pvt. Ltd.

B-4/142, IInd Floor

Safdarjung Enclave

New Delhi - 110029

Tel : +91-11-26169902, 03

Fax : +91-11-26169904

Email : sales@shafindia.com

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Asia Pacific Broadcasting Union

PO Box 1164,

59700 Kuala Lumpur,

Malaysia

E-mail: info@abu.org.my

Tel: +60-3-22823592

Fax: +60-3-2282-5292

Sony India

A-31, Mohan Cooperative Estate,

Mathura Road,

New Delhi 110044

Tel: +91-11-66006600

Fax: +91-11-26959141

E-Mail: bppmktg@ap.sony.com

CMS-NVL

"NVL House", 198/2,

Garhi, East of Kailash,

Opp. Sapna Cinema,

New Delhi-110065

Tel. : +91-11-26218527

Fax : +91-11-26225955

E-mail : ashokksehgal@yahoo.com

Ahuja Radios

215, Okhla Industrial Estate

New Delhi - 110 020 - INDIA

Tel.: +91-11-26831549, 41612475

Fax: +91-11-26847287, 41616563

Email: admin@ahujaradios.com, ahuja@ahujaradios.com

Hytech India

18, Poorvi Marg, Vasant Vihar,

New Delhi-110 057.

Tel: +91-11-41661709, 26140652

Fax: +91-11-26142084

E-Mail: hytech@vsnl.com, hytech_del@airtelbroadband

Telerad (A Division of ASE Ltd)

Head Office: 89-92, G.I.D.C Naroda Industrial Area,

Ahmedabad - 382 330 - Gujarat

Delhi: 408-810,

Vishwa Sadan, District Center,

Janakpuri - New Delhi - 110 058

Tel: (Ahmedabad) +91-79-22813017/3117

(Delhi) +91-11-25541731/9330

Fax: (Ahmedabad) +91-79-22821592 (Delhi) +91-11- 2554 8507

Email : telsales@icenet.net, tlrddel@airtelbroadband.in

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Promedia

R-31, Laxmi Industrial Estate

Link Road,

Andheri (W)

Mumbai - 400 053

Tel: +91-022-67021711, 26354891

Fax: +91-22-67021714, 26354819

Mob: +91-9820023077

E-Mail: info@promediain.net, nikhil@promediain.net

AGP Broadcast Infrastructure Pvt. Ltd.

226-A, Pocket B, Mayur Vihar Phase II

New Delhi

Tel: +91-11-22783543, 22785668

Telfax: +91-11-22783543

Mob: +91-9811143367

Email: info@agpbroadcast.com

Sonodyne

98, NB Block E, New Alipore

Kolkata - 700 053

Tel: +91-33-24570418, 24583406

Fax: +91-33-24787243

Mob: +91-9811143367

Email: response@sonodyne.com

Visual Technologies India Pvt. Ltd.

370-371/2, First Floor,

Hospital Road,

Jangpura, New Delhi - 110 014.

Tel: +91-11-24379961-64, 24378592-94, 24373965

Fax: +91-11-24378591, 2437 5843

E-Mail: vtidel@vtipl.com, vtihyd@vtipl.com

Setron India Private Limited

E-2, Greater Kailash Enclave -1,

New Delhi - 110048.

Tel: +91-11-26242250, 26241150/601

Fax: +91-11-26242150

E-Mail: sales@setronindia.com

Deepjyot Electronics

B-4/228, Safdarjung Enclave

(Behind Safdarjung Club)

New Delhi - 110 029

Tel: +91-11-26187495, 2617 7791

Fax: +91-11-4135 4357

E-Mail: deepjyot.electronics@gmail.com

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C. Radio Automation and IT

ENCO India

A-238, 2 Floor

Defence Colony

New Delhi-110023

Tel: +91-9871580444

E-Mail: arjun@enco.com

Contact Person : Arjun Srivastav

HCL Infinet Ltd.

E-4, 5, 6 ; Sector 11,

Noida 201301

Tel: +91-120-2552973

Fax: +91-120-2552973

E-Mail: anuragku@hcl.in

D. FM Transmitter equipment

Bharat Electronics Ltd. (BEL)

Outer Ring Road

Nagavara

Bangalore - 560045 - Karnataka

Tel: +91-080-28303280 (Broadcast systems Division)

Fax: +91-080-25039305

Email: mohanda@bel.co.in (D.A.Mohan, GM Broadcast & Telecom)

West Bengal Electronics Industry Development Corp. (WEBEL)

Webel Bhavan,

Block - EP & GP,

Sector - V, Salt Lake

Kolkata - 700 091 - West Bengal

Tel: +91-33-23578392

Fax: +91-33-23571708/23571739

Email: contact@webel-india.com

Rohde & Schwarz India Pvt. Ltd.

A-27 First Floor,

Mohan Co-operative Industrial Estate

Mathura Road, New Delhi 110 044

Tel: +91-11-42535400

Fax: +91-11-42535433

E-Mail: Nidhi.sharma@rohde-schwarz

Broadcast Electronics

A-238, Defence Colony,

New Delhi-110024

Tel: +91-11-24333340

Fax:+91-11-24333339

E-Mail: sm@btgroup.co.in

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APPENDIX 5

USEFUL WEB BASED RESOURCES

One of the most useful resources available to any CR station or CR practitioner

is the internet, that worldwide network of computers and databases that

offers us the largest collection of information ever created. The list below

highlights a few of the most useful websites that will add and expand on the

information contained in this manual.

1. www.communityradiotoolkit.net

A website for CR practitioners and information seekers, run by Radio Regen

(Wales), and supported by the UK Dept. for Culture, Media and Sport (DCMS).

The website is a mine of information on CR - including the CRT Handbook

- and offers access to several online discussion fora for registered users, to

discuss various aspects of their experiences with CR. It is also a source of

information and news on CR related events in Europe and the UK area.

2. CR India (http://mail.sarai.net/mailman/listinfo/cr-india)

A mailing list/discussion forum on community radio in India, with a rapidly

growing membership. A very useful platform for the exchange of queries

and information on CR regulations, technology and setup, the list includes

most of the organizations and individuals active in the CR movement in

India.

3. http://www.mib.nic.in

The website of the Govt. of India’s Ministry of Information and Broadcasting.

It carries all the background to the current CR (FM) policy, including the

application documents and guidelines described in Section A, as well as a

very detailed FAQ on the application and licensing process, and the technical

parameters that have to be followed (see http://mib.nic.in/CRS/FAQ.htm).

The site also gives details on the current commercial FM rollout.

4. http://www.unesco.org + http://www.undp.org

The United Nations Educational, Scientific and Cultural Organization

(UNESCO) and the United Nations Development Programme (UNDP)

websites. Both organizations are involved with development of community

radio worldwide, and have supported the establishment of CRS across the

globe. Both have also worked on the extensive documentation of CR best

practices and experiences. The websites need to be explored a bit to find

information relevant to Indian practitioners of CR – it is wise to narrow the

search in both cases to the sub-sites for India and South Asia – but there are

a huge number of links to documents and information on CR around the

world in the main sites.

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5. www.freeradio.org

The website of the Free Radio Berkeley movement, dedicated to international

radio action training. The FRB movement works on the ‘airwaves are free’

principle, and encourages the sharing of DIY radio information that removes

restrictions on access to technology and broadcasting controls. Focused

primarily on democratizing radio access in the United States – and

consequently, opposition to FCC control – the website contains information

on training courses run by the organization, as well as resources like circuit

diagrams and online ordering processes for radio related circuitry and DIY

kits. Also contains a numbetr of useful ‘how to’ pages.

6. www.radiophony.org

Radiphony is an Indian company dedicated to the free airwaves principle,

that works to provide easy to use audio and radio technology solutions for

Indian users. The site allows access to resources like the eLocutor, a software

that allows severely physically challenged individuals to work on a computer.

The site also contains detailed FAQs on low power radio and the CR process

and setup in India. Also includes – like Free Radio Berkeley – access to

information on a DIY simple radio transmitter circuit which can be

constructed by most amateur enthusiasts.

7. http://prometheusradio.org

The Prometheus Radio Project is a US based initiative to democratise media

access by promoting low power FM. While its events calendar is primarily

US-centric, the tech resources are exhaustive, with a number of pages devoted

to concepts around low power broadcasting, and galleries of photos

illustrating simple solutions and field radio techniques. The International

section includes their experiences is supporting and developing low power

FM stations in Tanzania. The project can also be contacted for radio station

setup consultancies.

8. http://www.resourcesair.com

The website of the All India Radio Resources Unit, which offers technical

consultancies to set up CRS. The website details the consultancy work they

undertake, and is an especially useful reference to understand the steps

involved in designing, setting up and testing a new FM station.

9. http://www.developingradiopartners.org

The website of Developing Radio Partners, a US based not-for-profit that

works towards empowering communities worldwide with access to low

cost radio technology. While there are no tech resources on the site, their

detailed case studies based on their experiences in Sierra Leone, Mongolia

and Southern Africa are interesting for the perspective they offer new CR

practitioners.

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10. http://www.becil.com

The website of Broadcast Engineering Consultants India Ltd. (BECIL). BECIL

has been one of the primary consultant agencies for broadcast setups in

India, especially where commercial radio and television have been

concerned. A Govt. of India enterprise, the website is a source for all kinds

of technical and broadcast event related news and information, and contains

links to CR application, licensing and guideline related information. The CR

link on the site explains BECIL’s consultancy work and the services it provides.

11. www.communityradionetwork.org

A website developed by VOICES (Bangalore, India) with UNDP support as

part of the same project under which the Community Radio Step by Step

manual was developed (See Bibliography). The website offers members a

discussion forum on various aspects of CR in India, as well as information

regarding setup, sustainability, technical know-how and equipment setups.

12. http://southasia.oneworld.net

The website of OneWorld South Asia (OWSA), the South Asian arm of the

international development organization OneWorld. The website offers

networking opportunities to grassroot agencies, and includes an extensive

events listing that covers grassroot communication initiatives like CR, one of

OWSA’s focus areas. OWSA produces and disseminates radio programming,

and conducts capacity building programmes on radio and readio technology

for field level organizations.

13. www.itrainonline.org/itrainonline/english/

community_radio.shtml

iTrainonline provides online training resources on a number of media related

subjects, ranging from audio and video to community radio. The community

radio page has links to an extensive list of documents and websites that give

information on CR, content development for CR, standard stylesheets from

professional media organizations, story ideas, and journalism tips. The

resources are catalogued under the heads Basics, General, Technical, and

Content Development.

14. http://www.transom.org/tools/index.php

Transom.org is an online resource site developed by Atlantic Public Media

to allow sharing and discussion on public media access. The site includes

several informative articles on recording and editing, selecting equipment,

and setting up a studio; as well as useful links to a variety of resources.

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15. www.bbctraining.com

Though not directly a CR resource, the BBC Online training website is an

enormous resource for learning the technology of radio per se, and the

content production techniques that have made the BBC one of the most well

known and respected broadcasting organizations in the world. The website

also includes online training courses on a variety of recording and production

techniques for radio.

16. http://www.apc.org/english/capacity/training

community_radio.shtml

The website for the Association for Progressive Communication, an

international association that works on internet and ICTs for social justice

and development. The website offers a number of resources – shared with

the iTrainonline website mentioned above – on community radio, as well as

resources on networking civil society organizations.

17. http://www.apnic.net/services/index.html

The Asia Pacific Network Information Center is a resource sharing online

organization that facilitates discussion on a variety of ICT and media related

subjects amng civil society organizations in the Asia-Pacific. It has a large

resources section that, while not directly referring to community radio

practitioners, has a lot of ICT related guidelines, resources and information.

18. http://en.wikipedia.org/wiki/Category:Radio_technology

The online contributory resource Wikipedia has a very interesting section

on radio terminology and history. This resource provides simple definitions

and a number of links to other resources, and changes very rapidly to reflect

new media inputs.

19. http://www.cdt21.com/

Website of Circuit Design, Inc., a manufacturer of low cost radio solutions.

Includes an RF design guide with a discussion of circuit diagrams, and an

online resource for calculations, and online articles on low power FM

applications

20. http://www.radioactive.org.uk/home.htm

Website of Radioactive, a UK based organization that works to help

communities set up low cost CRS. Radioactive’s website offers a number of

turnkey CRS packages and setup diagrams that offer CR practitioners and

NGOs a point of reference for deciding their equipment combinations and

setups. Many of the packages offered have attached costings that allow an

assessment of the overall costs involved.

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Tabing, Louie

How to do Community Radio: A

Primer for Community Radio

Operators. UNESCO (2005)

Fraser, Colin & Estrada, Sonia

Restrepo

Community Radio Handbook

UNESCO (2005)

Bandana Mukhopadhyay

Community Radio In India Step

by Step.

VOICES & UNESCO (2004)

MacDonald, Max

Community Radio: A Marketing

Manual. Community Broadcasting

Foundation, Australia (1995)

Worsoe, Neil & Oesterlund, Per

Configuration of Radio Stations &

Media Centers: A Practical Guide to

procurement of technical

equipment for community media

initiatives

UNESCO with DaniCom & Niels

Worsoe (2004)

Free Radio Berkeley

Micropower Broadcasting -

A Technical Primer.

Free Radio Berkeley, 2004

UNESCO

Ten Steps for Establishing a

Sustainable Multipuprose

Community Telecenter.

UNESCO Regional Office, Bangkok

(2003)

Smith, Eric T.

Acoustics 101: Practical guidelines

for constructing acoustically

accurate spaces

Auralex Acoustics (2003)

BIBLIOGRAPHY

Adam Gordon & Harford, Nicola

Radio & HIV/AIDS: A guide for

radio practitioners, health workers

and donors.

UNAIDS/Media Action International

(2003)

Girard, Bruce & Van Der Spek, Jo

The Potential for Community Radio

in Afghanistan

Comunica (2002)

Radio Regen

Community Radio Toolkit: CRT

Handbook

Radio Regen (2006)

Sims, Martin

Community Radio Manual

Open Society Foundation for

Southern Africa/National

Community Radio Forum/CAF-SCO

(2002)

Sims, Martin

Community Radio Technical

Manual

Open Society Foundation for

Southern Africa/National

Community Radio Forum/CAF-SCO

(2002)

Govt. of India

Policy Guidelines for setting up

Community Radio Stations in India

Ministry of Information &

Broadcasting, Govt. of India

(2006)

Govt. of India

Application Form for Grant of

Permission to set up CRS (FM)

Ministry of Information &

Broadcasting, Govt. of India

(2006)

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