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INSTRUCTION MANUAL

Innovator

LX Series

Analog

VHF Translator

AXCERA, LLC

103 FREEDOM DRIVE P.O. BOX 525 LAWRENCE, PA 15055-0525 USA

(724) 873-8100 • FAX (724) 873-8105

www.axcera.com • info@axcera.com

LX Series VHF Translator Table of Contents

LX Series, Rev. 0 iv

TABLE OF CONTENTS

CHAPTER 1 INTRODUCTION

SECTION PAGE

1.1 Manual Overview...................................................................................1-1

1.2 Assembly Designators............................................................................1-1

1.3 Safety..................................................................................................1-2

1.4 Contact Information...............................................................................1-2

1.5 Return Material Procedure ......................................................................1-2

1.6 Limited One Year Warranty for Axcera Products........................................1-3

CHAPTER 2 SYSTEM DESCRIPTION, MAINTENANCE

& REMOTE CONTROL CONNECTIONS

2.0 System Overview ..................................................................................2-1

2.2 Exciter/Amplifier Chassis Assembly .........................................................2-2

2.2.1 Receiver Module...........................................................................2-2

2.2.2 IF Processor Module .....................................................................2-2

2.2.3 VHF/UHF Upconverter Module........................................................2-5

2.2.4 Control & Monitoring/Power Supply Module.....................................2-6

2.2.5 Exciter Power Amplifier Module, VHF HB .........................................2-8

2.3 RF Output Assemblies..........................................................................2-10

2.4 Control and Status...............................................................................2-10

2.5 System Operation................................................................................2-10

2.5.1 Principles of Operation................................................................2-10

2.6 Maintenance .......................................................................................2-11

2.7 Customer Remote Connections .............................................................2-12

CHAPTER 3 SITE CONSIDERATIONS, INSTALLATION AND SETUP PROCEDURES

3.1 Site Considerations................................................................................3-1

3.2 Unpacking the Cabinet, Chassis w/Modules and DTV mask filter .................3-4

3.3 Installing the Chassis w/Modules and filters..............................................3-4

3.4 AC Input...............................................................................................3-6

3.5 Setup and Operation..............................................................................3-6

3.5.1 Input Connections........................................................................3-6

3.5.2 Initial Turn On .............................................................................3-7

3.5.2.2 Receiver Module LEDs on Front Panel ....................................3-8

3.5.2.3 IF Processor Module LEDs on Front Panel...............................3-8

3.5.2.4 VHF/UHF Upconverter Module LEDs on Front Panel .................3-8

3.5.2.5 Controller Module LEDs on Front Panel ..................................3-8

3.5.2.6 Power Amplifier Module LEDs on Front Panel..........................3-8

3.5.3 Front Panel Screens for the Exciter/Amplifier Chassis Assembly.........3-9

3.5.5 Operation Procedure...................................................................3-18

LX Series VHF Translator Table of Contents

LX Series, Rev. 0 v

TABLE OF CONTENTS - (Continued)

CHAPTER 4 CIRCUIT DESCRIPTIONS

4.2 Receiver Module (not used in the digital translator system)........................4-1

4.2.1 IF ALC Board ...............................................................................4-1

4.2.2 VHF Mixer/PLL Board ....................................................................4-2

4.2.3 VHF High Band Preamplifier Board .................................................4-2

4.3 IF Processor Module...............................................................................4-2

4.3.1 IF Processor Board .......................................................................4-3

4.3.1.1 Modulator Selected..............................................................4-3

4.3.1.2 External Modulated IF Selected.............................................4-3

4.3.1.3 Main IF Signal Path (Part 1 of 3)...........................................4-3

4.3.1.4 Input Level Detector Circuit..................................................4-3

4.3.1.5 Pin-Diode Attenuator Circuit.................................................4-5

4.3.1.6 Main IF Signal Path (Part 2 of 3)...........................................4-5

4.3.1.7 Amplitude and Phase Pre-Correction Circuits..........................4-6

4.3.1.8 Main IF Signal Path (Part 3 of 3)...........................................4-7

4.3.1.9 ALC Circuit .........................................................................4-7

4.3.1.10 Fault Command.................................................................4-8

4.3.1.11 ±12 VDC needed to operate Board......................................4-8

4.4 VHF/UHF Upconverter Module.................................................................4-8

4.4.1 Downconverter Board ...................................................................4-8

4.4.2 L-Band PLL Board.........................................................................4-9

4.4.3 First Conversion Board..................................................................4-9

4.4.4 Upconverter Control Board ............................................................4-9

4.5 Control Monitoring/Power Supply Module ...............................................4-10

4.5.1 Power Protection Board...............................................................4-10

4.5.1.1 +12 VDC Circuits ..............................................................4-11

4.5.1.2 -12 VDC Circuits ...............................................................4-11

4.5.2 Control Board ............................................................................4-11

4.5.2.1 Schematic Page 1..............................................................4-11

4.5.2.2 Schematic Page 2..............................................................4-12

4.5.2.3 Schematic Page 3..............................................................4-12

4.5.2.4 Schematic Page 4..............................................................4-13

4.5.2.5 Schematic Page 5..............................................................4-13

4.5.3 Switch Board .............................................................................4-14

4.5.4 Switching Power Supply Assembly................................................4-14

4.8 Power Amplifier Module, VHF Low Band .................................................4-14

4.8.1 VHF Low Band Driver Assembly ...................................................4-14

4.8.2 VHF Low Band Amplifier Board.....................................................4-15

4.8.3 VHF Coupler Board .....................................................................4-15

4.8.4 Amplifier Control Board...............................................................4-16

4.8.4.1 Schematic Page 1..............................................................4-16

4.8.4.2 Schematic Page 2..............................................................4-16

4.8.4.3 Current Monitoring Sections of the Board.............................4-17

4.8.4.4 Schematic Page 3, RF Power Detector Circuits......................4-17

LX Series VHF Translator Table of Contents

LX Series, Rev. 0 vi

TABLE OF CONTENTS - (Continued)

SECTION PAGE

CHAPTER 5 DETAILED ALIGNMENT PROCEDURES

5.1 Module Replacement..............................................................................5-1

5.1.1 Initial Test Setup..........................................................................5-1

5.2 LX Series Exciter/Amplifier Chassis Assembly ...........................................5-2

5.2.1 Receiver Module Assembly ............................................................5-2

5.2.2 IF Processor Module Assembly.......................................................5-2

5.2.3 VHF/UHF Upconverter Assembly ....................................................5-2

5.3 Changing the Analog Translator Output Channel Procedure........................5-3

5.4 Adjusting Manual AGC, Auto AGC and AGC cutback in Analog Translator .....5-4

5.4.1 Setting the Manual AGC................................................................5-4

5.4.2 Setting the Auto AGC....................................................................5-4

5.4.3 Setting the AGC Cutback...............................................................5-4

5.5 Calibration of Forward & Reflected Power of Analog Translator ...................5-4

5.5.1 Calibration of the Translator Forward Output Power .........................5-5

5.5.2 Calibration of the Translator Reflected Power ..................................5-5

5.6 Linearity Correction Adjustment for the Analog Translator..........................5-6

5.7 Frequency Response Delay Equalization Adjustment for Analog Translator...5-6

APPENDICES

APPENDIX A SYSTEM AND EXCITER/AMPLIFIER DRAWINGS

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-1

Chapter 1

Introduction

1.1 Manual Overview

This manual explains the installation,

setup, alignment, and maintenance

procedures for the Innovator LX Series

VHF translator. It is important that you

read all of the instructions, especially

the safety information in this chapter,

before you begin to install or operate

the unit.

This instruction manual is divided into

five chapters and supporting

appendices. Chapter 1, Introduction,

contains information on the assembly

numbering system used in the manual,

safety, maintenance, return procedures,

and warranties. Chapter 2, System

Description, Maintenance & Remote

Control Connections, describes the

transmitter and includes discussions on

system control and status indicators,

maintenance, and remote control

connections. Chapter 3, Site

Considerations, Installation and Setup

Procedures, explains how to unpack,

install, setup, and operate the

transmitter. Chapter 4, Circuit

Descriptions, contains circuit level

descriptions for boards and board level

components in the transmitter.

Chapter 5, Detailed Alignment

Procedures, provides information on

adjusting the system assemblies for

optimal operation. Appendix A

contains the System, Remodulator &

Exciter/Amplifier drawings and parts

lists.

1.2 Assembly Designators

Axcera has assigned assembly numbers,

Ax designations such as A1, where

x=1,2,3…etc, to all assemblies, modules,

and boards in the system. These

designations are referenced in the text of

this manual and shown on the block

diagrams and interconnect drawings

provided in the appendices. The Block

Diagrams, Interconnects, Schematics,

Assembly Drawings and Parts Lists are

arranged in increasing numerical order in

the appendices. Section titles in the text

for assembly or module descriptions or

alignment procedures contain the

associated part number(s) and the

relevant appendix that contains the

drawings for that item.

The cables that connect between the

boards within a tray or assembly and

that connect between the trays, racks

and cabinets are labeled using Brady

markers.

Figure 1-1 is an example of a Brady

marked cable. There may be as few as

two or as many as four Markers on any

one cable. These Brady markers are

read starting furthest from the

connector. If there are four Brady

Markers, this marker is the transmitter

number such as transmitter 1 or

transmitter 2. The next or the furthest

Brady Marker is the rack or cabinet

number on an interconnect cable or the

board number within a tray. The next

number on an interconnect cable is the

Tray location or number. The Brady

marker closest to the connector is the

jack or connector number on an

interconnect cable or the jack or

connector number on the board within a

tray.

Figure 1-1 Brady Marker Identification

Drawing

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-2

1.3 Safety

The VHF translator systems

manufactured by Axcera are designed to

be easy to use and repair while providing

protection from electrical and mechanical

hazards. Please review the following

warnings and familiarize yourself with the

operation and servicing procedures

before working on the transmitter

system.

Read All safety Instructions – All of

the safety instructions should be read

and understood before operating this

equipment.

Retain Manuals – The manuals for the

transmitter should be retained at the

transmitter site for future reference.

Axcera provides two sets of manuals for

this purpose; one set can be left at the

office while one set can be kept at the

site.

Heed all Notes, Warnings, and

Cautions – All of the notes, warnings,

and cautions listed in this safety section

and throughout the manual must be

followed.

Follow Operating Instructions – All of

the operating and use instructions for the

transmitter should be followed.

Cleaning – Unplug or otherwise

disconnect all power from the equipment

before cleaning. Do not use liquid or

aerosol cleaners. Use a damp cloth for

cleaning.

Ventilation – Openings in the cabinet

and module front panels are provided for

ventilation. To ensure the reliable

operation of the driver/transmitter, and

to protect the unit from overheating,

these openings must not be blocked.

Servicing – Do not attempt to service

this product yourself until becoming

familiar with the equipment. If in doubt,

refer all servicing questions to qualified

Axcera service personnel.

Replacement Parts – When

replacement parts are used, be sure that

the parts have the same functional and

performance characteristics as the

original part. Unauthorized substitutions

may result in fire, electric shock, or other

hazards. Please contact the Axcera

Technical Service Department if you have

any questions regarding service or

replacement parts.

1.4 Contact Information

The Axcera Field Service Department can

be contacted by phone at (724) 873-

8100 or by fax at (724) 873-8105.

Before calling Axcera, please be prepared

to supply the Axcera technician with

answers to the following questions. This

will save time and help ensure the most

direct resolution to the problem.

1. What are the Customers’ Name

and call letters?

2. What are the model number and

type of transmitter?

3. Is the transmitter digital or

analog?

4. How long has the transmitter

been on the air? (Approximately

when was the transmitter

installed.)

5. What are the symptoms being

exhibited by the transmitter?

Include the current control/power

supply LCD readings and the

status of LEDs on the front

panels of the modules. If

possible, include the

control/power supply LCD

readings before the problem

occurred.

1.5 Return Material Procedure

To insure the efficient handling of

equipment or components that have been

returned for repair, Axcera requests that

each returned item be accompanied by a

Return Material Authorization Number

(RMA#).

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-3

The RMA# can be obtained from any

Axcera Field Service Engineer by

contacting the Axcera Field Service

Department at (724) 873-8100 or by fax

at (724) 873-8105. This procedure

applies to all items sent to the Field

Service Department regardless of

whether the item was originally

manufactured by Axcera.

When equipment is sent to the field on

loan, an RMA# is included with the unit.

The RMA# is intended to be used when

the unit is returned to Axcera. In

addition, all shipping material should be

retained for the return of the unit to

Axcera.

Replacement assemblies are also sent

with an RMA# to allow for the proper

routing of the exchanged hardware.

Failure to close out this type of RMA# will

normally result in the customer being

invoiced for the value of the loaner item

or the exchanged assembly.

When shipping an item to Axcera, please

include the RMA# on the packing list and

on the shipping container. The packing

slip should also include contact

information and a brief description of why

the unit is being returned.

Please forward all RMA items to:

AXCERA, LLC

103 Freedom Drive

P.O. Box 525

Lawrence, PA 15055-0525 USA

For more information concerning this

procedure, call the Axcera Field Service

Department @ (724) 873-8100.

Axcera can also be contacted through e-

mail at info@axcera.com and on the

Web at www.axcera.com.

1.6 Limited One Year Warranty for

Axcera Products

Axcera warrants each new product that

it has manufactured and sold against

defects in material and workmanship

under normal use and service for a

period of one (1) year from the date of

shipment from Axcera's plant, when

operated in accordance with Axcera's

operating instructions. This warranty

shall not apply to tubes, fuses,

batteries, bulbs or LEDs.

Warranties are valid only when and if

(a) Axcera receives prompt written

notice of breach within the period of

warranty, (b) the defective product is

properly packed and returned by the

buyer (transportation and insurance

prepaid), and (c) Axcera determines, in

its sole judgment, that the product is

defective and not subject to any misuse,

neglect, improper installation,

negligence, accident, or (unless

authorized in writing by Axcera) repair

or alteration. Axcera's exclusive liability

for any personal and/or property

damage (including direct, consequential,

or incidental) caused by the breach of

any or all warranties, shall be limited to

the following: (a) repairing or replacing

(in Axcera's sole discretion) any

defective parts free of charge (F.O.B.

Axcera’s plant) and/or (b) crediting (in

Axcera's sole discretion) all or a portion

of the purchase price to the buyer.

Equipment furnished by Axcera, but not

bearing its trade name, shall bear no

warranties other than the special hours-

of-use or other warranties extended by

or enforceable against the manufacturer

at the time of delivery to the buyer.

NO WARRANTIES, WHETHER

STATUTORY, EXPRESSED, OR

IMPLIED, AND NO WARRANTIES OF

MERCHANTABILITY, FITNESS FOR

ANY PARTICULAR PURPOSE, OR

FREEDOM FROM INFRINGEMENT,

OR THE LIKE, OTHER THAN AS

SPECIFIED IN PATENT LIABILITY

ARTICLES, AND IN THIS ARTICLE,

SHALL APPLY TO THE EQUIPMENT

FURNISHED HEREUNDER.

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-4

F WARNING!!!

× HIGH VOLTAGE Ø

DO NOT ATTEMPT TO REPAIR OR TROUBLESHOOT THIS EQUIPMENT UNLESS

YOU ARE FAMILIAR WITH ITS OPERATION AND EXPERIENCED IN

SERVICING HIGH VOLTAGE EQUIPMENT. LETHAL VOLTAGES ARE PRESENT

WHEN POWER IS APPLIED TO THIS SYSTEM. IF POSSIBLE, TURN OFF

POWER BEFORE MAKING ADJUSTMENTS TO THE SYSTEM.

« RADIO FREQUENCY RADIATION HAZARD «

MICROWAVE, RF AMPLIFIERS AND TUBES GENERATE HAZARDOUS RF

RADIATION THAT CAN CAUSE SEVERE INJURY INCLUDING CATARACTS,

WHICH CAN RESULT IN BLINDNESS. SOME CARDIAC PACEMAKERS MAY BE

AFFECTED BY THE RF ENERGY EMITTED BY RF AND MICROWAVE

AMPLIFIERS. NEVER OPERATE THE TRANSMITTER SYSTEM WITHOUT A

PROPERLY MATCHED RF ENERGY ABSORBING LOAD ATTACHED. KEEP

PERSONNEL AWAY FROM OPEN WAVEGUIDES AND ANTENNAS. NEVER

LOOK INTO AN OPEN WAVEGUIDE OR ANTENNA. MONITOR ALL PARTS OF

THE RF SYSTEM FOR RADIATION LEAKAGE AT REGULAR INTERVALS.

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-5

EMERGENCY FIRST AID INSTRUCTIONS

Personnel engaged in the installation, operation, or maintenance of this equipment are urged to become

familiar with the following rules both in theory and practice. It is the duty of all operating personnel to be

prepared to give adequate Emergency First Aid and thereby prevent avoidable loss of life.

RESCUE BREATHING

1. Find out if the person is

breathing.

You must find out if the person

has stopped breathing. If you

think he is not breathing, place

him flat on his back. Put your ear

close to his mouth and look at his

chest. If he is breathing you can

feel the air on your cheek. You

can see his chest move up and

down. If you do not feel the air

or see the chest move, he is not

breathing.

2. If he is not breathing, open

the airway by tilting his head

backwards.

Lift up his neck with one hand

and push down on his forehead

with the other. This opens the

airway. Sometimes doing this will

let the person breathe again by

himself.

3. If he is still not breathing,

begin rescue breathing.

-Keep his head tilted backward.

Pinch nose shut.

-Put your mouth tightly over his

mouth.

-Blow into his mouth once every

five seconds

-DO NOT STOP rescue breathing

until help arrives.

LOOSEN CLOTHING - KEEP

WARM

Do this when the victim is

breathing by himself or help is

available. Keep him as quiet as

possible and from becoming

chilled. Otherwise treat him for

shock.

BURNS

SKIN REDDENED: Apply ice cold water to burned

area to prevent burn from going deeper into skin

tissue. Cover area with a clean sheet or cloth to

keep away air. Consult a physician.

SKIN BLISTERED OR FLESH CHARRED: Apply

ice cold water to burned area to prevent burn from

going deeper into skin tissue.

Cover area with clean sheet or cloth to keep away

air. Treat victim for shock and take to hospital.

EXTENSIVE BURN - SKIN BROKEN: Cover area

with clean sheet or cloth to keep away air. Treat

victim for shock and take to hospital.

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-6

dBm, dBw, dBmV, dBµV, & VOLTAGE

EXPRESSED IN WATTS

50 Ohm System

WATTS PREFIX dBm dBw dBmV dBµV VOLTAGE

1,000,000,000,000 1 TERAWATT +150

+120

100,000,000,000 100 GIGAWATTS +140

+110

10,000,000,000 10 GIGAWATTS +130

+100

1,000,000,000 1 GIGAWATT +120

+ 99

100,000,000 100 MEGAWATTS +110

+ 80

10,000,000 10 MEGAWATTS +100

+ 70

1,000,000 1 MEGAWATT + 90 + 60

100,000

100 KILOWATTS + 80 + 50

10,000 10 KILOWATTS + 70 + 40

1,000 1 KILOWATT + 60 + 30

100 1 HECTROWATT + 50 + 20

50 + 47 + 17

20 + 43 + 13

10 1 DECAWATT + 40 + 10

1 1 WATT + 30 0 + 77 +137 7.07V

0.1 1 DECIWATT + 20 - 10 + 67 +127 2.24V

0.01 1 CENTIWATT + 10 - 20 + 57 +117 0.707V

0.001 1 MILLIWATT 0 - 30 + 47 +107 224mV

0.0001 100 MICROWATTS - 10 - 40

0.00001

10 MICROWATTS - 20 - 50

0.000001 1 MICROWATT - 30 - 60

0.0000001 100 NANOWATTS - 40 - 70

0.00000001 10 NANOWATTS - 50 - 80

0.000000001 1 NANOWATT - 60 - 90

0.0000000001 100 PICOWATTS - 70 -100

0.00000000001 10 PICOWATTS - 80 -110

0.000000000001 1 PICOWATT - 90 -120

TEMPERATURE CONVERSION

°F = 32 + [(9/5) °C]

°C = [(5/9) (°F - 32)]

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-7

USEFUL CONVERSION FACTORS

TO CONVERT FROM TO MULTIPLY BY

mile (US statute) kilometer (km) 1.609347

inch (in) millimeter (mm) 25.4

inch (in) centimeter (cm) 2.54

inch (in) meter (m) 0.0254

foot (ft) meter (m) 0.3048

yard (yd) meter (m) 0.9144

mile per hour (mph) kilometer per hour(km/hr) 1.60934

mile per hour (mph) meter per second (m/s) 0.44704

pound (lb) kilogram (kg) 0.4535924

gallon (gal) liter 3.7854118

U.S. liquid

(One U.S. gallon equals 0.8327 Canadian gallon)

fluid ounce (fl oz) milliliters (ml) 29.57353

British Thermal Unit watt (W) 0.2930711

per hour (Btu/hr)

horsepower (hp) watt (W) 746

NOMENCLATURE OF FREQUENCY BANDS

FREQUENCY RANGE DESIGNATION

3 to 30 kHz VLF - Very Low Frequency

30 to 300 kHz LF - Low Frequency

300 to 3000 kHz MF - Medium Frequency

3 to 30 MHz HF - High Frequency

30 to 300 MHz VHF - Very High Frequency

300 to 3000 MHz UHF - Ultrahigh Frequency

3 to 30 GHz SHF - Superhigh Frequency

30 to 300 GHz EHF - Extremely High Frequency

LETTER DESIGNATIONS FOR UPPER FREQUENCY

BANDS

LETTER FREQ. BAND

L 1000 - 2000 MHz

S 2000 - 4000 MHz

C 4000 - 8000 MHz

X 8000 - 12000 MHz

Ku 12 - 18 GHz

K 18 - 27 GHz

Ka 27 - 40 GHz

V 40 - 75 GHz

W 75 - 110 GHz

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-8

RETURN LOSS VS. VSWR

1.001 1.01 1.1 2.0

VSWR

LX Series VHF Translator Chapter 1

Introduction

LX Series, Rev. 0 1-9

ABBREVIATIONS/ACRONYMS

AC Alternating Current

AFC Automatic Frequency Control

ALC Automatic Level Control

AM Amplitude modulation

AGC Automatic Gain Control

ATSC Advanced Television Systems

Committee

AWG American wire gauge

BER Bit Error Rate

BW Bandwidth

DC Direct Current

D/A Digital to analog

DTV Digital Television

dB Decibel

dBm Decibel referenced to

1 milliwatt

dBmV Decibel referenced to

1 millivolt

dBw Decibel referenced to 1 watt

FEC Forward Error Correction

FM Frequency modulation

Hz Hertz

ICPM Incidental Carrier Phase

Modulation

I/P Input

IF Intermediate Frequency

LED Light emitting diode

LSB Lower Sideband

MPEG Motion Pictures Expert Group

O/P Output

PLL Phase Locked Loop

PCB Printed circuit board

QAM Quadrature Amplitude

Modulation

SMPTE Society of Motion Picture and

Television Engineers

VSB Vestigial Side Band

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-1

Chapter 2

System Description, Maintenance & Remote Control Connections

2.0 System Overview

This analog translator is a complete VHF

internally diplexed modular television

translator. There are three systems, one

that operates at CH:6 at a nominal visual

output power of 20W or a DTV output of

10W, one that operates at CH:10 at a

nominal visual output power of 20W or a

DTV output of 10W, and one that

operates at CH:8 at a nominal visual

output power of 100W or a DTV output of

50W..

The Analog LX Series translator is made

up of the modules and assemblies as

listed in Table 2-1.

Figure 2-1:Exciter/Amplifier w/Remodulator Front View

Table 2-1: Exciter/Amplifier w/Remodulator Translator Assemblies

ASSEMBLY DESIGNATOR

TRAY/ASSEMBLY NAME PART NUMBER

A2 Exciter Amplifier Chassis Assembly,

V2, LX Series 1304052 (110 VAC)

A2-A11 Backplane Board, V2, LX Series 1304047

A1 Receiver Module (used in the analog

translator system) 1304001 (VHF High

Band)

A3 IF Processor Module 1301938

A4 Control/Power Supply Module 1301936 (110 VAC)

A5 VHF/UHF Upconverter Module 1303829

A6 Power Amplifier Module, 20 W Analog

1305833 (VHF High

Band

A24

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-2

2.2 (A2) Exciter Amplifier Chassis

Assembly, 110 VAC (1304052;

Appendix A)

This chassis assembly is factory set for

operation using 110 VAC. All of the

modules except the power amplifier

module and the power supply section of

the Control & Monitoring/Power Supply

Module, plug directly into a backplane

board. The backplane board provides

module to module interconnection as well

as interconnection to remote command

and control connectors.

2.2.1 (A1) Receiver Module

Assembly, VHF High Band

(1304001; Appendix A)

NOTE: The Receiver module is not used

in the digital system.

NOTE: For analog translator operation

the Receiver IF output at A2-J13 is

connected to the Modulated IF input

Jack A2-J6 and the On Channel RF input

is connected to A2-J12.

The VHF Receiver converts a low level

RF input signal (-65 to –15 dBm) to an

IF frequency of 44 MHz, filters off any

unwanted out of band energy, and

normalizes the level so that it can be

applied to the IF processor assembly.

The receiver consists of three boards,

the VHF High Band Preamplifier Board

(1306445), the Mixer/PLL Board

(1306472), and the IF ALC Board

(1304003). The RF input is applied first

to the VHF preamplifier board, which

filters off out of channel energy and

amplifies the input signal. The RF output

is connected to the Mixer/PLL board,

which converts the signal down to an IF

frequency of 44 MHz. The IF output is

cabled to the IF ALC board, which

amplifies the signal, filters off any

unwanted out of band energy and

controls its own IF gain to make sure

that the IF output level is constant.

There is also a provision to apply +12V

to the RF input center conductor to

power an external preamplifier.

CAUTION: Do not hook up the RF

input to any test equipment with the

DC bias applied. Always move the

jumper W1 on J2, on the UHF

Preamplifier Board, to the Bias off

position, between pins 2 & 3, to

prevent possible damage to the test

equipment.

Table 2-5: Receiver Front Panel Switch

SWITCH FUNCTION

MAN/AUTO ALC

SW1

When Manual ALC is selected, the level is set by the

Manual ALC Pot R57 located on the mixer/PLL board.

(NOTE: The pot is factory set and needs no adjustment

by the customer).

When Auto ALC is selected, the level control circuit will

automatically increase or decrease the ALC to maintain

the desired output level.

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-3

Table 2-6: Receiver Front Panel Status Indicators

LED FUNCTION

PLL1 Fault DS6 Displays the status of the Local oscillator PLL

PLL 2 Fault DS8 Displays status of optional input frequency correcting PLL

DC on center conductor DS4 Displays whether or not DC is applied to the RF input

center conductor

Man ALC Gain DS7 Displays when ALC is switched to Manual bypass

ALC Fault DS5 Displays ALC status

Table 2-7: Receiver Front Panel Control Adjustments

POTENTIOMETERS DESCRIPTION

Manual Gain R57 Adjusts the gain of the receiver when the ALC is bypassed.

A/V Ratio R50 Adjusts the ratio between the visual and aural carriers.

Table 2-8: Receiver Front Panel Samples

SMA CONNECTORS DESCRIPTION

Receiver IF J13 Sample of the IF output of the IF ALC Board.

Receiver LO J2 Sample of the LO generated on the UHF Mixer PLL Board.

2.2.2 (A3) IF Processor Module

Assembly (1301938; Appendix A)

The (A3) IF Processor Assembly contains

the IF Processor Board (1301977). The IF

Processor provides pre-correction to

ensure broadcast quality output signal.

The pre-correction consists of amplitude

linearity correction, Incidental Carrier

Phase Modulation (ICPM) correction and

frequency response correction.

The IF Processor module is configured

either for an analog or digital system.

Pin 13C of the IF Processor module is

grounded in analog systems and left not

connected in digital systems. An IF

Processor Interlock signal is used to

report the presence of the IF Processor

module to the Control Monitoring board.

If the IF Processor interlock signal is not

present, the LX Series translator RF

output is Muted (turned off). If an

analog IF Processor module is installed

and the Modulation Present signal is not

true, the LX Series Translator output is

Muted (turned off).

The Control & Monitoring/Power Supply

module uses the IF Processor module for

System output power control. Through

the front panel display or a remote

interface, an operator can set the RF

output power level of the translator.

The range of RF power adjustment is

between 0% (full off) and 105% (full

power plus). A front panel IF Processor

module potentiometer sets the upper

limit of RF power at 120%. The

system's Control Monitoring board

compares the RF Power Monitoring

module RF power level with the desired

level and uses the IF Power Control PWM

line to correct for errors.

In digital systems, a digital level control

(DLC) voltage is generated on the IF

Processor module and sent to an

external digital modulator (DT1B/C). RF

power control is implemented by

changing the DLC voltage provided to

the external digital modulator. The 'RF

High' potentiometer sets the upper

adjusted range of RF control circuit

output to 120%.

The IF Processor module provides a

reference ALC voltage to the system's

Upconverter. When the ALC voltage

decreases, the Upconverter

automatically lowers the system output

power through the AGC circuits.

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-4

The IF Processor module has a front

panel switch to select Auto or Manual

ALC. When Manual ALC is selected, the

reference ALC voltage is set by a front

panel potentiometer. In this condition,

the RF power level control circuit is

removed from use. When the ALC select

switch is changed to Auto, the RF power

level control circuit will start at low

power and increase the RF output until

the desired output power is attained.

The IF Processor module Modulation

Present signal is monitored. If the

modulation level is too low or non-

existent, a Modulation Present Fault is

reported to the Control Monitoring

board. When the controller detects this

fault, it can be set to Automatically Mute

the translator or in Manual mode the

translator will continue to operate at

25% output.

The IF Processor module Input Signal

level is monitored. If the signal level is

too low or non-existent, an Input Fault

is reported on the Control Monitoring

board. When the IF Processor board

detects an Input Signal Fault it

automatically Mutes the translator. The

system controller does not Mute on an

IF Processor Input Fault.

Table 2-9: IF Processor Front Panel Switch

SWITCH FUNCTION

MAN/AUTO ALC

When Manual ALC is selected, the reference ALC voltage is set

by the ALC Gain front panel potentiometer.

When Auto ALC is selected, the IF level control circuit will

automatically increase the IF output until the desired output

power is attained.

Table 2-10: IF Processor Front Panel Status Indicators

LED FUNCTION

INPUT FAULT (Red) When lit it indicates that there is a loss of the IF Input signal to the

IF Processor. Translator can be set to Mute on an IF Input Fault.

ALC Fault (Red) When lit it indicates that the required gain to produce the desired

output power level has exceeded the operational range of the ALC

circuit. The LED will also be lit when ALC is in Manual.

MUTE (Red) When lit it indicates that the IF input signal is cut back but the

enable to the Power Supply is present and the +32 VDC remains on.

Table 2-11: IF Processor Front Panel Control Adjustments

POTENTIOMETERS

DESCRIPTION

FREQUENCY

RESPONSE

EQUALIZER

These three variable resistors, R103, R106 & R274, adjust the

depth of gain for the three stages of frequency response correction.

ALC GAIN Adjusts the gain of the translator when the translator is in the Auto

ALC position.

MAN GAIN Adjusts the gain of the translator when the translator is in the

Manual ALC position.

LINEARITY

CORRECTION

These three variable resistors adjust the threshold cut in for the

three stages of linearity pre-correction. R211 and R216, the top

two pots, are adjusted to correct for in phase amplitude distortions.

R 231, the bottom pot, is adjusted to correct for quadrature phase

distortions.

Table 2-12: IF Processor Front Panel Sample

SMA CONNECTOR DESCRIPTION

IF SAMPLE Sample of the pre-corrected IF output of the IF Processor

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-5

2.2.3 (A5) VHF/UHF Upconverter

Module Assembly (1303829;

Appendix A)

The VHF/UHF Upconverter Module

Assembly contains (A1) a Downconverter

Board Assembly (1303834), (A3) a First

Conversion Board, LX Series (1303838),

(A2) a L-Band PLL Board, LX Series

(1303846) and (A4) an Upconverter

Control Board (1304760).

A 0 dBm 44 MHz IF input to the

upconverter through the backplane

board is applied to a mixer mounted on

the first conversion board. Also applied

to the mixer is a nominal 1 GHz LO1.

The mixer converts it to a nominal

frequency centered at 1044 MHz. A

filter selects the appropriate conversion

product, which is then amplified to a

level of approximately –4 dBm. The

frequency of the first conversion LO1

can be shifted by ± 10 kHz to generate

channel offsets of 10kHz. For +offsets

the frequency is 999.99 MHz and for –

offsets the frequency is 1000.01 MHz.

This signal is applied to a second mixer

mounted on the downconverter board

that converts it back to a broadcast

channel (2-69) by an LO2 that operates

in 100kHz steps between 1.1-1.9 GHz

depending on the channel selected. The

LO2 frequency equals the Channel

center frequency plus the LO1 frequency

plus 44 MHz. (As an example CH14+:

Center Frequency is 473.01 MHz and

LO1 is 999.99 MHz therefore LO2 is

473.01 + 999.99 + 44, which equals

1517.00 MHz.)

The output of the mixer is applied to a

900 MHz Low pass filter to remove

unwanted conversion products. The

resulting signal is amplified and applied

to a Pin diode attenuator before it is

connected to the output of the

upconverter. This pin diode attenuator

adjusts the gain of the module and is

controlled by an Automatic Gain Control

circuit, which maintains a constant

power out of the upconverter, and also

the translator, that connects to the

power amplifier module.

Table 2-13: VHF/UHF Upconverter Front Panel Switch

SWITCH FUNCTION

MAN/AUTO AGC

(Left Manual, Right AGC)

When Manual AGC is selected, the reference AGC voltage is

set by the AGC Manual Gain front panel potentiometer.

When Auto AGC is selected, the RF power level control circuit

will automatically increase the RF output until the desired

output power is attained.

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-6

Table 2-14: VHF/UHF Upconverter Front Panel Status Indicators

LED FUNCTION

PLL 1 Fault

(Red) When lit it indicates that the 1 GHz PLL is unlocked

PLL 2 Fault

(Red) When lit it indicates that the 1.1 –1.9 GHz PLL is unlocked

AGC Fault

(Red) When lit it indicates that the AGC is out of range.

AGC Override

(Red) When lit it indicates that the AGC is cutting back due to too much

drive to the driver module.

Man Gain

(Amber) When lit it indicates that the AGC is bypassed in Manual.

Table 2-15: VHF/UHF Upconverter Front Panel Control Adjustments

POTENTIOMETERS

DESCRIPTION

MAN GAIN ADJ Adjusts the gain of the upconverter and translator when in the

Manual AGC position.

AGC ADJ Adjusts the gain of the upconverter and translator when in the Auto

AGC position.

AGC CUTBACK ADJ

(AGC OVERRIDE) Adjusts the point at which the translator will cut back in power, due

to too much drive, when the Translator is in Auto AGC.

Table 2-16: VHF/UHF Upconverter Front Panel Samples

SMA CONNECTOR DESCRIPTION

LO1 SAMPLE Sample of the 1 GHz nominal LO1 signal in the Upconverter as

generated on the L-Band PLL Board.

LO2 SAMPLE Sample of the 1.1-1.9 GHz LO2 signal in the Upconverter as

generated on the First Conversion Board.

RF SAMPLE Sample of the On Channel RF Output of the Upconverter

2.2.4 (A4) Control/Power Supply

Module Assembly, 110VAC

(1301936; Appendix A)

This (A4) Control & Monitoring/Power

Supply Assembly was configured at the

factory for operation at 110 VAC. The

assembly is made up of a Control Board

(1302021), a Power Protection Board

(1302837) and a Switch Board (1527-

1406).

The Assembly also contains a switching

power supply that provides ±12 VDC to

the rest of the modules in the chassis

and +32 VDC to the Power Amplifier

module.

The Assembly provides all translator

control and monitoring functions. The

Front panel LCD allows monitoring of

system parameters, including forward

and reflected power, transistor currents,

module temperatures and power supply

voltages. The LCD screens are detailed

in Chapter 3.

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-7

Table 2-17: Controller/Power Supply Display

DISPLAY FUNCTION

LCD A 4 x 20 display providing a four-line readout of the internal

functions, external inputs, and status. See Chapter 3,

Controller/Power Supply Display Screens, for a listing of displays.

Table 2-18: Controller/Power Supply Status Indicator

LED FUNCTION

OPERATE

(green)

When lit it indicates that the translator is in the Operate Mode. If

translator is Muted the Operate LED will stay lit, the translator will

remain in Operate, until the input signal is returned.

FAULT

(red or green)

Red indicates that a problem has occurred in the translator. The

translator will be Muted or placed in Standby until the problem is

corrected.

DC OK

( red or green ) Green indicates that the switchable fuse protected DC outputs that

connect to the modules in the translator are OK.

Table 2-19: Controller/Power Supply Control Adjustments

POTENTIOMETERS

DESCRIPTION

DISPLAY CONTRAST Adjusts the contrast of the display for desired viewing of screen.

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-8

2.2.6 (A6) Power Amplifier Module

Assembly, VHF High Band,

(1305833; Appendix A)

NOTE: This 20W Analog power amplifier

module is used in the VHF High Band

Translator.

The (A6) Power Amplifier Module

Assembly is made up of a VHF High Band

Coupler Board (1211-1004), a VHF

Amplifier Control Board (1308260), and a

High Band VHF Amplifier Pallet Assembly

(1305820).

The Power Amplifier Module contains

Broadband LDMOS amplifiers that cover

the VHF High Band with no tuning

required. The module amplifies the RF

output of the Upconverter to

approximately 22 watts Peak of Sync

Visual. A cable, located on the rear

chassis, connects the RF output from the

Upconverter at J23 to J24 the RF input to

the PA Assembly. The High Band VHF

Amplifier Pallet Assembly (1305820) is

made from a Delta RF Technology pallet

PA25-VHF-HB.

The PA module contains RF monitoring

circuitry for both an analog and a digital

system. Control and monitoring lines to

the Power Amplifier module are routed

through the floating blind-mate

connector of the Control &

Monitoring/Power Supply module. The

Driver Power Amplifier module contains

a control and monitoring board. This

board monitors RF output power, RF

reflected power, the current draw of

amplifier sections, the supply voltage,

and the temperature of the PA heat sink.

The RF power detector circuit outputs

vary with operating frequency. These

circuits must be calibrated at their

intended operating frequency. Front

panel adjustment potentiometers are

used to calibrate the following:

Power Amplifier Calibration Adjustments

in Analog Systems

R201 Reflected Power Cal

R202 Visual/Forward Power Cal

R203 Aural Power Cal

R204 Visual Offset Zero

R205 Aural Null

In analog systems, the Aural power of

an Exciter Driver Power Amplifier and

the Aural power of any external PA

amplifiers will not be reported by the

system Control Monitoring module.

Additionally the Visual power of these

amplifiers is reported as Forward Power

just like in digital systems. In analog

systems, aural and visual power will only

be reported for the final system RF

output.

In this translator, system power is

measured in the Power Amplifier

module. The wired connections are

transferred through the power supply

connector to the backplane board on a

five position header. All four positions

of control board switch SW1 must be set

ON to route these lines as the system's

RF power signals.

The Forward Power of the Exciter Driver

Power Amplifier module is routed to the

Upconverter module as AGC #1. A

system over-drive condition is detected

when this value rises above 0.9 VDC.

When an over-drive condition is

detected, the Upconverter module

reduces its RF output level. For values

less than 0.9 VDC, the Upconverter uses

this voltage for automatic gain.

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-9

Table 2-23: Power Amplifier Status Indicator

LED FUNCTION

ENABLED

(Green) When lit Green, it indicates that the PA is in the Operate Mode. If a Mute

occurs, the PA will remain Enabled, until the input signal is returned.

DC OK

(Green) When lit Green, it indicates that the fuse protected DC inputs to the PA

module are OK.

TEMP

(Green) When lit Green, it indicates that the temperature of the heatsink assembly in

the module is below 78°C.

MOD OK

(Green) When lit Green, it indicates that the PA Module is operating and has no faults.

MOD OK

(Red)

If the Module OK LED is Red and blinking a fault is present.

1 Blink indicates Amplifier Current Fault. If the Module OK LED is Red and

blinking a fault is present, as indicated below by the number of blinks and a

pause then a repeat of the number of blinks and a pause.

2 Blinks indicate Temperature Fault.

3 Blinks indicate +32V Power Supply Over Voltage Fault.

4 Blinks indicate +32V Power Supply Under Voltage Fault.

5 Blinks indicate Reflected Power Fault.

6 Blinks indicate +12V or –12V Power Supply Fault.

MOD OK

(Amber)

A blinking Amber Mod OK LED indicates the power output of the amplifier

module is below 65%. (NOTE: Only in Amplifier Code Versions 3.7A or later &

System Controller Code Versions 3.9C or later.)

Table 2-24: Power Amplifier Control Adjustments

POTENTIOMETERS

DESCRIPTION

RFL CAL Adjusts the gain of the Reflected Power monitoring circuit

VISUAL CAL Adjusts the gain of the Visual / Forward Power monitoring circuit

AURAL CAL Adjusts the gain of the Aural Power monitoring circuit

VISUAL ZERO Adjusts the offset of the Forward Power monitoring circuit

AURAL NULL Adjusts the offset of the Forward Power monitoring circuit based on

the Aural signal level.

Table 2-25: Power Amplifier Sample

DISPLAY FUNCTION

FWD SAMPLE RF sample of the amplified signal being sent out the module on J25.

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-10

2.3 RF Output Assemblies

The RF output from the exciter power

amplifier is at the RF output jack, an “N”

connector J25, PA RF Output, of the

chassis assembly.

2.4 Control and Status

A 4 x 20 display located on the front of

the Control & Monitoring/Power Supply

Module is used in the LX Series

translator for control of the operation

and display of the operating parameters

of the translator. Refer to Chapter 3 for

descriptions of the screens.

2.5 System Operation

When the translator is in operate, as set

by the menu screen located on the

Control & Monitoring Module, the

following occurs. The IF Processor will be

enabled and the mute indicator on the

front panel will be extinguished. The

+32 VDC stage of the Power Supply in

the Control & Monitoring Module is

enabled, the operate indicator on the

front panel is lit and the DC OK on the

front panel should also be green. The

enable and DC OK indicators on the PA

Module will also be green.

When the translator is in standby. The IF

Processor will be disabled, the mute

indicator on the front panel will be red.

The +32 VDC stage of the Power Supply

in the Control & Monitoring Module is

disabled, the operate indicator on the

front panel will be extinguished and the

DC OK on the front panel should remain

green. The enable indicator on the PA

Module is also extinguished.

If the translator does not switch to

Operate when the operate menu is

switched to Operate, check that all faults

are cleared and that the remote control

terminal block stand-by signal is not

active.

The translator can be controlled by the

presence of a modulated input signal. If

the input signal to the translator is lost,

the translator will automatically cutback

and the input fault indicator on the IF

Processor module will light. When the

video input signal returns, the translator

will automatically return to full power and

the input fault indicator will be

extinguished.

2.5.1 Principles of Operation

Operating Modes

This translator is either operating or in

standby mode. The sections below

discuss the characteristics of each of

these modes.

Operate Mode

Operate mode is the normal mode for

the translator when it is providing RF

power output. To provide RF power to

the output, the translator will not be in

mute. Mute is a special case of the

operate mode where the +32 VDC

section of the power supply is enabled

but there is no RF output power from

the translator. This condition is the

result of a fault that causes the firmware

to hold the IF Processor module in a

mute state.

Operate Mode with Mute Condition

The translator will remain in the operate

mode but will be placed in mute when

the following fault conditions exists in

the translator.

• Upconverter is unlocked

• Upconverter module is not present

• IF Processor module is not present

Entering Operate Mode

Entering the operate mode can be

initiated a few different ways by the

transmitter control board. A list of the

actions that cause the operate mode to

be entered is given below:

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-11

• A low on the Remote Transmitter

Operate line.

• User selects "OPR" using switches

and menus of the front panel.

• Receipt of an “Operate CMD” over

the serial interface.

There are several fault or interlock

conditions that may exist in the

translator that will prevent the translator

from entering the operate mode. These

conditions are:

• Power Amplifier heat sink

temperature greater than 78°C.

• Translator is Muted due to conditions

listed above.

• Power Amplifier Interlock is high

indicating that the amplifier is not

installed.

Standby Mode

The standby mode in the translator

indicates that the output amplifier of the

translator is disabled.

Entering Standby Mode

Similar to the operate mode, the

standby mode is entered using various

means. These are:

• A low on the Remote Translator

Stand-By line.

• Depressing the “STB” key on

selected front panel menus.

• Receipt of a “Standby CMD” over the

serial interface.

Auto Standby Mode

The FCC requires that certain translators

automatically switch to standby

operation on loss of video input. The LX

Series translator incorporates this

feature as a user configurable setting.

When Auto Stand-By on modulation loss

is selected in the set-up menus, the

translator temporarily switches to

standby after ten seconds of modulation

loss. When the modulated signal as

reported by the IF Processor module is

again present, the translator

automatically returns to Operate mode.

This feature is implemented in

transmitter software versions 1.4 and

above.

RF System Interlock

A RF System Interlock signal is provided

through TB30-5. When this signal's

circuit is completed to ground such as

through a wire between TB30-5 and

TB30-15, the translator is allowed to

operate. If this circuit is opened, the

translator switches to a Mute condition.

This circuit may be completed through

coax relay contacts and reject load

contact closures to assure the RF output

system is available to receive the

translator's output RF signal. This

feature is implemented in translator

software versions 1.4 and above.

Operating Frequency

The LX Series translator controller is

designed to operate on the VHF

frequencies. The exact output frequency

of the translator can be set to one of the

standard VHF frequencies, or to a

custom frequency using the software

channel set-up menu on the Controller

Module.. The Power detectors in the

translator are frequency dependent,

therefore detectors of power amplifiers

are calibrated at their frequency of use.

The detectors for System RF monitoring

are also calibrated at the desired

frequency of use. Refer to Chapter 5 for

the Channel Change Procedure.

2.6 Maintenance

The Innovator LX Series Translator is

designed with components that require

little or no periodic maintenance except

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-12

for the routine cleaning of the fans and

the front panels of the modules and the

periodic check of general tightness of

hardware.

It is recommended that periodically, the

time interval depends on the amount of

movement the cabinet receives, all

mounting hardware, holding tray slides,

shelving and mounting plates inside the

cabinet are checked for tightness. All

screws and bolts that are accessible

should be tightened initially when the

translator is received and periodically

thereafter if the translator is moved by

vehicle. All coaxial connectors, hard-line

connections and hardware holding

combiners, splitters, or any other

mounted items should be checked and

tightened. Check the front panel

thumbscrews that hold the Exciter/Driver

Sleds, Amplifier Module and Power

Supply Sleds in place are tight. This is

especially important after the translator

has been transported.

The amount of time between cleanings

depends on the conditions within the

transmitter room. While the electronics

have been designed to function even if

covered with dust, a heavy buildup of

dust, dirt, or insects will affect the

cooling of the components. This could

lead to a thermal shutdown or the

premature failure of the affected module.

When the front panels of the modules

become dust covered, the module should

be pulled out and any accumulated

foreign material should be removed.

NOTE: To remove the driver/power

amplifier module, mounted in the

exciter/amplifier assembly, the input and

output cables must be removed from the

rear of the module and also a 6/32” x ½”

Philips screw, mounted between the two

connectors, needs to be removed before

the module will pull out. After removal of

the screw, which is used to hold the

module in place during shipping, it does

not need to be replaced.

NOTE: To remove the Combiner Module,

found in the external power amplifier

assembly, the output cable must be

removed from the rear of the module and

also two 8/32” x ½” Philips screws,

mounted above the connector, need to

be removed before the module will pull

out. After removal of the screws, which

are used to hold the module in place

during shipping, they do not need to be

replaced.

A vacuum cleaner, utilizing a small,

wand-type attachment, is an excellent

way to suction out the dirt. Alcohol and

other cleaning agents should not be used

unless you are certain that the solvents

will not damage components or the silk-

screened markings on the modules and

boards. Water-based cleaners can be

used, but do not saturate the

components. The fans and heatsinks

should be cleaned of all dust or dirt to

permit the free flow of air for cooling

purposes.

It is recommended that the operating

parameters of the driver/translator be

recorded from the LEDs on the modules

and the LCD system metering on the

control/monitoring module at least once

a month. It is suggested that this data be

retained in a rugged folder or envelope.

2.7 Customer Remote Connections

The remote monitoring and operation of

the translator is provided through jacks

TB30 and TB31 located on the rear of the

chassis assembly. If remote connections

are made to the translator, they must be

made through plugs TB30 and TB31 at

positions noted on the translator

interconnect drawing and Table 2-26.

TB30 and TB31 are 18 position terminal

blocks that are removable from their

sockets to make connections easier. Just

grasp and pull connector straight out.

After connections are made, replace the

connector and push firmly to seat the

connector in the socket.

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-13

Figure 2-2: Exciter/Amplifier Chassis Assembly Rear View

Table 2-26: LX Series Chassis Assembly Hard Wired Remote Interface Connections to

TB30 or TB31, 18 pos. Terminal Blocks Located on the Rear of the Assembly

Signal Name Pin

Designations Signal Type/Description

RMT Transmitter

State TB30-1 Discrete Open Collector Output - A low indicates that

the translator is in the operate mode.

RMT Transmitter

Interlock TB30-2

Discrete Open Collector Output - A low indicated the

translator is OK or completes a interlock daisy chain.

When the translator is not faulted, the interlock circuit

is completed.

RMT Transmitter

Interlock Isolated

Return TB30-3

Ground - Configurable ground return which can be

either jumpered directly to ground or it can be the

“source” pin of an FET so that the transmitter interlock

can be daisy chained with other transmitters. This

signal does not directly interface to the

microcontroller.

RMT AUX IO 1 TB30-4

Discrete Open Collector Inputs, Discrete Open Drain

Outputs, or 0 - 5 VDC Analog Input - When used as an

output, this line is pulled to +5 VDC with a 1.0 kO

resistor for logic high and pulled to ground for a low.

A diode allows this line to be pulled up to 12 VDC.

When used as a digital input, this line considers all

values over 2 Volts as high and those under 1 volt as

low. As an analog input, this line is protected by a 5.1

zener diode.

RMT RF System

Interlock TB30-5

When this signal's circuit is completed to ground such

as through a jumper between TB30-5 and TB30-15,

the translator is allowed to operate. If this circuit is

opened, the translator switches to a Mute condition.

Implemented in transmitter software versions 1.4 and

above.

TB30

TB31

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-14

Signal Name Pin

Designations Signal Type/Description

RMT

Transmitter

Operate TB30-6 Discrete Open Collector Input - A pull down to ground

on this line indicates that the translator is to be placed

into the operate mode.

RMT

Transmitter

Stand-By TB30-7 Discrete Open Collector Input - A pull down to ground

on this line indicates that the translator is to be placed

into the standby mode.

RMT Power Raise TB30-8 Discrete Open Collector Input - A pull down to ground

on this line indicates that the translator power is to be

raised.

RMT Power Lower TB30-9 Discrete Open Collector Input - A pull down to ground

on this line indicates that the translator power is to be

lowered.

RMT

System Reflect

Power TB30-10

Analog Output (0 to 4.0 V). This is a buffered loop

through of the calibrated “System Reflected Power ”

and indicates the translator's reflected output power.

The scale factor is 25% = 3.2V.

RMT System

Visual/Forward

Power TB30-11

Analog Output (0 to 4.0 V). This is a buffered loop

through of the calibrated “System Visual/Avg. Power ”.

Indicates the translator's Visual / Average power.

Scale factor is 100% = 3.2V.

RMT

System Aural

Power (Not used

in DTV system)

TB30-12

Analog Output (0 to 4.0 V). This is a buffered loop

through of the calibrated “System Aural Power ”.

Indicates the translator's forward Aural output power.

The scale factor is 100% = 3.2V.

RMT Spare 1 TB30-13 Remote connection to spare module - Use is TBD.

RMT Spare 2 TB30-14 Remote connection to spare module - Use is TBD.

RMT +12 VDC TB30-16 +12 VDC available through Remote w/ 2 Amp re-

settable fuse.

RMT -12 VDC TB30-18 -12 VDC available through Remote w/ 2 Amp re-

settable fuse.

IF Processor

IF Signal Select TB31-3

Discrete Open Collector Input – By connecting a low to

this pin, the Modulator IF source is used by the IF

Processor module. When floating the IF from the

internal or external Receiver is used. (NOTE: The IF

Processor board must be configured for external

switching by placing jumper W11 on J29 between pins

1 & 2 for the modulated IF input at J6 to be used).

IF Processor

DLC Voltage TB31-4 Analog Output (0 to 5.00 V). This is the input of IF

Processor module for digital system RF output power

control.

UC AGC #2

Voltage TB31-5

Auxiliary Analog Input (0 to 1V). This voltage is used

by the Upconverter for gain control. Linear signal with

display resolution of 0.01 %. Primary signal source is

J34-1.

Ground Return TB31-12 Ground Return pin.

System Reflected

Power TB31-13

Analog Input (0 to 1.00 V). This is the input of the

“System Reflected Power ” indicating the translator's

reflected output power. The scale factor is 25% =

0.80V.

System Visual /

TB31-14

Analog Input (0 to 1.00 V). This is the input of the

LX Series VHF Translator Chapter 2, System Description,

Maintenance & Remote Control Connections

LX Series, Rev. 0 2-15

Signal Name Pin

Designations Signal Type/Description

Forward Power “System Visual / Forward Power ” indicating the

translator's forward Visual / Forward output power.

The scale factor is 100% = 0.80V.

System Aural

Power (Not used

in DTV system) TB31-15

Analog Input (0 to 1.00 V). This is the input of the

“System Aural Power ” indicating the translator's

forward Aural output power. The scale factor is 100%

= 0.80V.

+12 VDC TB31-16 +12 VDC available through Remote w/ 2 Amp re-

settable fuse.

Ground Return TB31-17 Ground Return pin.

-12 VDC TB31-18 -12 VDC available through Remote w/ 2 Amp re-

settable fuse.

RMT Ground TB30-15, and

17 Ground pins available through Remote

RMT Ground TB31-1, 2, 6 to

12 Ground pins available through Remote

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-1

Chapter 3

Site Considerations, Installation and Setup Procedures

3.1 Site Considerations

There are special considerations that need

to be taken into account before the

Innovator LX Series translator can be

installed. For example, if the installation is

completed during cool weather, a heat-

related problem may not surface for many

months, suddenly appearing during the

heat of summer. This section provides

planning information for the installation

and set up of the translator.

The AC input and current requirements

for analog/digital LX Series translator is

110 VAC @ 15 Amps. Check that your

site has the needed power requirements.

The LX Series Translators are designed

and built to provide long life with a

minimum of maintenance. The

environment in which they are placed is

important and certain precautions must be

taken. The three greatest dangers to the

translator are heat, dirt, and moisture.

Heat is usually the greatest problem,

followed by dirt, and then moisture. Over-

temperature can cause heat-related

problems such as thermal runaway and

component failure. Each amplifier module

in the translator contains a thermal

interlock protection circuit that will shut

down that module until the temperature

drops to an acceptable level.

A suitable environment for the translator

can enhance the overall performance and

reliability of the translator and maximize

revenues by minimizing downtime. A

properly designed facility will have an

adequate supply of cool, clean air, free of

airborne particulates of any kind, and no

excessive humidity. An ideal environment

will require temperature in the range of

40° F to 70° F throughout the year,

reasonably low humidity, and a dust-free

room. It should be noted that this is rarely

if ever attainable in the real world.

However, the closer the environment is to

this design, the greater the operating

capacity of the translator.

The fans are designed and built into the

translator will remove the heat from

within the modules, but additional means

are required for removing this heat from

the building. To achieve this, a few issues

need to be resolved. The first step is to

determine the amount of heat to be

removed from the transmitter room.

There are generally three sources of heat

that must be considered. The first and

most obvious is the heat from the

translator itself. This amount can be

determined for a 100 Watt translator by

subtracting the average power to the

antenna (69.5 watts) from the AC input

power (675 watts) and taking this

number in watts (605.5) and then

multiplying it by 3.41. This gives a result

of 2065, the BTUs to be removed every

hour. 12,000 BTUs per hour equals one

ton. Therefore, a 1/4 ton air conditioner

will cool a 100W translator.

The second source of heat is other

equipment in the same room. This

number is calculated in the same way as

the equation for BTUs. The third source

of heat is equally obvious but not as

simple to calculate. This is the heat

coming through the walls, roof, and

windows on a hot summer day. Unless

the underside is exposed, the floor is

usually not a problem. Determining this

number is usually best left up to a

qualified HVAC technician. There are far

too many variables to even estimate this

number without reviewing the detailed

drawings of the site that show all of the

construction details. The sum of these

three sources is the bulk of the heat that

must be removed. There may be other

sources of heat, such as personnel, and

all should be taken into account. Now

that the amount of heat that must be

removed is known, the next step is to

determine how to accomplish this. The

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-2

options are air conditioning, ventilation, or

a combination of the two. Air conditioning

is always the preferred method and is the

only way to create anything close to an

ideal environment.

Ventilation will work quite well if the

ambient air temperature is below 100° F,

or about 38° C, and the humidity is kept

at a reasonable level. In addition, the air

stream must be adequately filtered to

ensure that no airborne particulates of

any kind will be carried into the translator.

The combination of air conditioning for

summer and ventilation during the cooler

months is acceptable when the proper

cooling cannot be obtained through the

use of ventilation alone and using air

conditioning throughout the year is not

feasible.

Caution: The use of air conditioning

and ventilation simultaneously is not

recommended. This can cause

condensation in the translators.

The following precautions should be

observed regarding air conditioning

systems:

1. Air conditioners have an ARI

nominal cooling capacity rating. In

selecting an air conditioner, do not

assume that this number can be

equated to the requirements of the

site. Make certain that the

contractor uses the actual

conditions that are to be

maintained at the site in

determining the size of the air

conditioning unit.

2. Do not have the air conditioner

blowing directly onto the translator.

Under certain conditions,

condensation may occur on, or

worse in, the translator.

3. Do not separate the front of the

translator from the back with the

thought of air conditioning only the

front of the unit. Cooling air is

drawn in at the front of all

translators and in the front and

back of others. Any attempt to

separate the front of the

translator from the rear of the

unit will adversely affect the flow

of cooling air.

4. Interlocking the translator with the

air conditioner is recommended to

keep the translator from operating

without the necessary cooling.

5. The periodic cleaning of all filters

is a must.

When using ventilation alone, the

following general statements apply:

1. The blower, with attendant filters,

should be on the inlet, thereby

pressurizing the room and

preventing dirt from entering the

translator.

2. The inlet and outlet vents should

be on the same side of the

building, preferably the leeward

side. As a result, the pressure

differential created by wind will be

minimized. Only the outlet vent

may be released through the roof.

3. The inlet and outlet vents should

be screened with 1/8-inch

hardware cloth (preferred) or

galvanized hardware cloth

(acceptable).

4. Cooling air should enter the room

as low as practical but in no case

higher than four feet above the

floor. The inlet must be located

where dirt, leaves, snow, etc., will

not be carried in with the cooling

air.

5. The exhaust should be located as

high as possible. Some ducting is

usually required to insure the

complete flushing of heated air

with no stagnant areas.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-3

6. The filter area must be large

enough to insure a maximum air

velocity of 300 cubic feet per

minute through the filter. This is

not a conservative number but a

never-exceed number. In a dusty

or remote location, this number

should be reduced to 150 CFM.

7. The inlet and outlet(s) must have

automatic dampers that close any

time the ventilation blower is off.

8. In those cases in which a translator

is regularly off for a portion of each

day, a temperature-differential

sensor that controls a small heater

must be installed. This sensor will

monitor inside and outside

temperatures simultaneously. If the

inside temperature falls to within

5° F of the outside temperature,

the heater will come on. This will

prevent condensation when the

ventilation blower comes on and

should be used even in the

summer.

9. A controlled air bypass system

must be installed to prevent the

temperature in the room from

falling below 40° F during

translator operation.

10. The blower should have two

speeds, which are thermostatically

controlled, and are interlocked

with the translator. The blower on

high speed must be capable of

moving the required volume of air

into a half inch of water pressure at

the required elevation. The free air

delivery method must not be used.

11. Regular maintenance of any filters

can not be overemphasized.

12. Above 4000 feet, for external

venting, the air vent on the

cabinet top must be increased to

an 8-inch diameter for a 1 kW

transmitter and to a 10 inch

diameter for 5 kW and 6 kW

transmitters. An equivalent

rectangular duct may be used but,

in all cases, the outlet must be

increased by 50% through the

outlet screen.

13. It is recommended that a site plan

be submitted to Axcera for

comments before installation

begins.

In calculating the blower requirements,

filter size, and exhaust size, if the total

load is known in watts, 2000 CFM into ½

inch of water will be required for each

5000 watts. If the load is known in BTUs,

2000 CFM into ½ inch of water will be

required for each 17,000 BTUs. The inlet

filter must be a minimum of seven

square feet, larger for dusty and remote

locations, for each 5000 watts or 17,000

BTUs. The exhaust must be at least four

square feet at the exhaust screen for

each 5000 watts or 17,000 BTUs.

The information presented in this section

is intended to serve only as a general

guide and may need to be modified for

unusually severe conditions.

A combination of air conditioning and

ventilation should not be difficult to

design (see Figure 3-1).

System interlocking and thermostat

settings should be reviewed with Axcera.

As with any equipment installation, it is

always good practice to consult the

manufacturer when questions arise.

Axcera can be contacted at (724) 873-

8100.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-4

Figure 3-1. 1 kW Minimum Ventilation Configuration

3.2 Unpacking the Cabinet, Chassis

w/modules and mask filter

Thoroughly inspect the cabinet, chassis

with modules and all other materials

upon their arrival. Axcera certifies that

upon leaving our facility the equipment

was undamaged and in proper working

order. The shipping containers should be

inspected for obvious damage that

indicates rough handling. Remove the

cabinet, if purchased, chassis and

modules, along with mask filter, from the

crates and boxes. Check for dents and

scratches or broken connectors,

switches, display, or connectors. Any

claims against in-transit damage should

be directed to the carrier. Inform Axcera

as to the extent of any damage as soon

as possible.

The modules are mounted to the chassis

assembly with slides that are on the top

and the bottom of the modules. There

are two thumb screws on the front panel

that hold each of the modules in place.

After placement of cabinet, all mounting

hardware, holding tray slides, shelving

and mounting plates inside the cabinet

should be checked for tightness. All

screws and bolts that are accessible

should be tightened initially when the

translator is received and periodically

thereafter if the translator is moved by

vehicle. All coaxial connectors, hard-line

connections and hardware holding

combiners, splitters, or any other

mounted items should be checked and

tightened. Check the front panel

thumbscrews that hold the Exciter/Driver

Sleds, Amplifier Module and Power

Supply Sleds in place are tight. This is

especially important after the translator

has been transported.

NOTE: Typically the translator is shipped

pre-installed into a cabinet and therefore

the following sections may be skipped.

3.3 Installing the Chassis w/modules

and filters

The chassis assembly is made to mount

in a standard 19” rack. The chassis

assembly mounts using the four #10

clearance mounting holes on the ends.

The chassis should be positioned; to

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-5

provide adequate air intake into the front

and the air exhaust of the fan(s) in the

rear; the ability to slide the modules out

for replacement purposes; the

installation of the bandpass filter, and

output transmission line. The chassis or

cabinet in which it is mounted should be

grounded using copper strapping

material.

NOTE: To remove the power amplifier

module, mounted in the exciter/amplifier

assembly, the input and output cables

must be removed from the rear of the

module and also a 6/32” x ½” Philips

screw, mounted between the two

connectors, needs to be removed before

the module will pull out. After removal of

the screw, which is used to hold the

module in place during shipping, it does

not need to be replaced. (See Figure 3-2)

Connect the output of the chassis

assembly at the “N” connector J25 to the

input of the mask filter. Connect the

transmission line for the antenna system

to the output of the mask filter.

Figure 3-2: Exciter/Amplifier Front and Rear View Reconnection Drawing

Figure 3-3: Translator Front and Rear View Reconnection Drawing

Shipping Screw

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-6

3.4 AC Input

Once the chassis and output connections

are in place, connect the AC power cords

from the exciter/amplifier chassis

assembly to 110 VAC outlets.

The AC input and current requirements

for analog/ digital LX Series translator is

110 VAC @ 15 Amps.

This completes the unpacking and

installation of the LX Series VHF

television translator. Refer to the setup

and operation procedures that follow

before applying power to the translator.

3.5 Setup and Operation

Initially, the translator should be turned

on with the RF output at the coupler

terminated into a dummy load of at least

25W. If a load is not available, check

that the output of the coupler is

connected to the antenna for your

system.

3.5.1 Input Connections

The input connections to the translator

are to the rear of the exciter/amplifier

chassis assembly.

Refer to the tables and description that

follows for detailed information on the

input connections to the

Exciter/Amplifier.

Figure 3-4: Rear View of the Analog Translator

J24

J25

TB30

TB31

J32

J34

J33

J11

J10

J19

J18

TB2

J13

J17

J12

J23

Exciter/

Driver

Chassis

Assembly

THIS CABLE IS USED

FOR ANALOG SYSTEM.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-7

Table 3-1: Rear Chassis Connections for the LX Series Exciter/Driver.

Port Type Function Impedance

J1 IEC AC Input N/A

TB02 Term (NOT USED) Base Band Audio Input 600O

J3 BNC (NOT USED) Composite Audio Input 75O

J4 BNC (NOT USED) SAP / PRO Audio Input 50O

J5 BNC (NOT USED) CW IF Input 50O

J6 BNC Modulated IF Input (In Analog System

connects to J13 50O

J7 BNC (NOT USED) Video Input (Isolated) 75O

J8 BNC (NOT USED) Visual IF Loop-Thru Output 50O

J9 BNC (NOT USED) Aural IF Loop-Thru Output 50O

J10 BNC External 10 MHz Reference Input 50O

J11 BNC System 10 MHz Reference Output 50O

J12 BNC Receiver RF Input (Used in Analog System) 50O

J13 BNC Receiver IF Output (In Analog System connects

to J6) 50O

J17 BNC (NOT USED) Video Loop-Thru (Isolated) 75O

J18 BNC (NOT USED) Visual IF Loop-Thru Input 50O

J19 BNC (NOT USED) Aural IF Loop-Thru Input 50O

J23 BNC Upconverter RF Output (Jumpered to J24) 50O

J24 BNC Power Amplifier RF Input (Jumpered to J23) 50O

J25 N Power Amplifier RF Output 50O

J32 RJ-45 SCADA (Input / Loop-Thru) CAT5

J33 RJ-45 SCADA (Input / Loop-Thru) CAT5

J34 RJ-45 System RS-485 Serial CAT5

TB30 Termination

Remote Control & Monitoring N/A

TB31 Termination

Remote Control & Monitoring N/A

3.5.2 Initial Turn On

Once the translator has been installed

and all connections have been made, the

process of turning on the equipment can

begin. Verify that AC power is present

and connected to the translator. Verify

all cables are properly connected and are

the correct type. Once these checks are

completed, the unit is ready to be turned

on using the following procedures.

Turn on the main AC power source that

supplies the AC to the translator. Check

that the AC power plug is connected to

J1 on the rear of the exciter/amplifier

chassis assembly. Check that the On/Off

circuit breaker, located on the rear of the

Exciter/Amplifier is On.

Monitor the LCD display located on the

front of the control/monitoring power

supply module in the exciter/amplifier

chassis assembly as you proceed

through this section. When the

translator is in the operate mode, the

STB menu appears on the screen. When

in the standby mode, the OPR menu

appears on the screen. Press the NXT

key after each menu to continue through

the sequence to the next screen.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-8

3.5.2.2 Receiver Module LEDs on

Front Panel

Fault Indicators:

PLL 1 FLT: This illuminates Red when

the Local Oscillator PLL is unlocked.

PLL 2 FLT: This illuminates Red when

the optional input frequency correcting

PLL is unlocked.

ALC FLT: This illuminates Red when the

ALC can not maintain output level.

Status Indicators:

DC ON I/P: This indicator will illuminate

Red when DC is applied to the RF input

center conductor.

MAN ALC: This illuminates Red when

the ALC can not maintain output level.

3.5.2.3 IF Processor Module LEDs on

Front Panel

Fault Indicators:

INPUT FAULT: This illuminates Red if

the input to the module is missing or

low.

ALC FAULT: This illuminates RED when

the needed ALC value to maintain the

output level is beyond the range of the

circuitry.

MUTE: This indicator will illuminate Red

when the translator is muted.

3.5.2.4 VHF/UHF Upconverter

Module LEDs on Front Panel

Fault Indicator:

AGC FAULT: This illuminates Red if the

required gain to produce the desired

output level is beyond the value set by

the AGC circuit. AGC out of range.

AGC OVERRIDE: This illuminates Red if

the drive to the driver module is too

high.

MAN GAIN: This illuminates Red if the

AGC is bypassed in Manual.

PLL 1: This illuminates Red if the 1 GHz

PLL is unlocked.

PLL 2: This illuminates Red if the 1.1-

1.9 GHz PLL is unlocked.

3.5.2.5 Controller Module LEDs on

Front Panel

Status Indicators:

OPERATE: This illuminates Green when

translator is in operate.

FAULT: This illuminates Red when a

fault has occurred in the translator.

DC OK: This illuminates Green when the

DC outputs that connect to the modules

in the translator are present.

3.5.2.6 Power Amplifier Module LEDs

on Front Panel

NOTE: Both the VHF High Band and

Low Band PA Modules have the same

front panel LEDs.

Status Indicators:

ENABLED: This illuminates Green when

the PA is in operate.

DC OK: This illuminates Green when the

DC inputs to the PA module are present.

TEMP: This illuminates Green when the

temperature of the heatsink in the PA is

below 78°C.

MOD OK: This illuminates Green when

the PA module is operating and has no

faults.

If the Module OK LED is Red and blinking

a fault is present. The meaning of the

blinking LED is as follows.

1 Blink: Indicates Amplifier Current

Fault.

2 Blinks: Indicate Temperature Fault.

3 Blinks: Indicate +32V Power Supply

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-9

Over Voltage Fault.

4 Blinks: Indicate +32V Power Supply

Under Voltage Fault.

5 Blinks: Indicate Reflected Power Fault.

6 Blinks: Indicate +12V or –12V Power

Supply Fault

If the Module OK LED is Amber and

blinking, it indicates the power output of

the amplifier has dropped below 65%.

(NOTE: Only in Amplifier Code Versions

3.7A or later and System Controller Code

Versions 3.9C or later.).

3.5.3 Front Panel Screens for the

Exciter/Amplifier Chassis Assembly

A 4 x 20 display located on the front of

the Control & Monitoring/Power Supply

Module is used in the LX Series

translator for control of the operation

and display of the operating parameters

of the translator. Below are the typical

display screens for the system and may

vary depending on your system. The ↑

and ↓ characters are special characters

used to navigate up or down through the

menu screens. Display text flashes on

discrete fault conditions for all screens

that display a fault condition. When the

translator is in operate mode, the STB

menu appears. When the translator is in

standby mode, the OPR menu appears.

Display Menu Screens for the LX Series Translator

Table 3-3: Menu 01 - Splash Screen #1

This is the first of the two transmitter splash screens that is shown for the first few

seconds after reset or after pushing the SPL button on the Main Screen. Will

automatically switch to the second splash screen.

Table 3-4: Menu 02- Splash Screen #2

This is the second of the two transmitter splash screens. Will automatically switch to the

Main Screen. The Model Number, Code Version Number and Firmware Number for your

system are displayed on this screen. Make note of these two numbers when conferring

with Axcera on software problems.

Table 3-5: Menu 10 - Main Screen:

This is the default main screen of the translator. When the translator is in operate,

the 'STB' characters appear, allowing an operator to place the translator in STANDBY, by

pushing the right most button located under to display. When the translator is in standby

the 'STB' characters are replaced with 'OPR' and the forward power values are displayed

as OFF. An operator can change the translator from STANDBY to OPERATE by pressing

the right most button on the front panel display. If the translator is in operate mode but

off due to a modulation fault, the display reports the system power as Auto Off. Pushing

the SPL button will display the two splash screens.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-10

If the ↓ key is activated the display changes to Menu 11, the System Error List Access

Screen. If the ↑ key is activated the display changes to Menu 13, the Transmitter

Configurations Access Screen.

Table 3-6: Menu 11 - Error List Access Screen

This screen of the translator shows the current number of system errors, displayed in

upper, right of screen, shown above is System Errors 0. and provides operator access to

view Menu 20, the error list screens, by pushing the ENT button if errors are indicated. .

If the ↓ key is pushed the display changes to Menu 12, Table 3-7, the Transmitter Device

Data Access Screen. If the ↑ key is activated the display returns to Menu 10, the Main

Screen. When ENT is pushed, if errors are present, Menu 20, Table 3-9, the System

Error List Display Screen is displayed with the error indicated.

Table 3-7: Menu 12 - Transmitter Device Data Access Screen

This screen of the translator allows access to various parameters of the translator

system. This is the entry point to Menu 30, the System Details Screens, by pausing the

ENT button. When the ENT button is pushed, Menu 30 is accessed. Go to Menu 30, Table

3-12 for set up details. Before pushing the ENT button: if the ↓ key is activated the

display changes to Menu 13, Transmitter Configurations Access Screen. If the ↑ key is

activated the display returns to Menu 11, the Error List Access Screen.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-11

Table 3-8: Menu 13 - Transmitter Configuration Access Screen

This screen of the translator allows access to various software settings of the translator

system. If ENT is pushed, go to Menu 40, Table 3-13, the access to transmitter

configuration and set up. Before pushing the ENT button: if the ↓ key is activated the

display returns to Menu 10, Main Screen. If the ↑ key is activated the display returns to

Menu 12, the Transmitter Device Data Access Screen.

Table 3-9: Menu 20 - Error List Display Screen

When ENT is pushed on the Error List Access Screen, Menu 11, if errors are present,

Menu 20, the System Error List Display Screen is displayed with the System Error

indicated as shown above. This screen of the translator allows access to the system

faults screens. Fault logging is stored in non-volatile memory. The translator's operating

state can not be changed in this screen. The 'CLR' switch is used to clear previously

detected faults that are no longer active. The ↑ key and ↓ key allow an operator to scroll

through the list of errors that have occurred. The ESC button is used to leave this screen

and return to Menu 11, Table 3-16, the Error List Access Screen.

The screen shown indicates a Modulator Module Interlock Fault, typically because the

Modulator is not present. It also indicates that there are a total of eight faults. The

other faults can be displayed by pushing the ↓ key button. To clear the displayed System

Error, fault, that is no longer active, push the button under CLR. Repeat to clear each

additional displayed System Error. If an error is active it will not clear.

NOTES: In Dual Exciter Systems with an Exciter Switcher, for the automatic switching to

the back up exciter to occur, the System Error, Fault, Log located in the Back Up Exciter

must be cleared of all Previous Faults, as described above.

With all Errors, faults, cleared the screen below should be displayed. Push the button

under ESC to return to Menu 11, Table 3-6, the Error List Access Screen.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-12

Menu 30 is entered by selecting ENT at Menu 12, Table 3-7.

Table 3-10: Menu 30 - Transmitter Device Details Screen

This screen allows access to the translator parameters of installed devices. The system is

configured to know which devices are present. Current values for all installed devices are

shown. If a module is not installed, only a "MODULE NOT PRESENT" message will be

displayed. The first screen displayed is Menu 30-1, Table 3-11, the System Details

Screen.

Table 3-11: Menu 30-1 – System Details Screen

The ↓ and ↑ arrows allow you to scroll through the different parameters of each device as

shown in Table 3-12 that follows. Each System Component is a different screen. The

proper IF Processor and the Driver or the Power Amplifier will be programmed for your

system. The External Amplifier Modules will only be used in high power translators.

Examples of External Amplifier Modules displays are: (AMP SET 1 MODULE 1) and (AMP

SET 2 MODULE 4).

Table 3-12: Transmitter Device Parameters Detail Screens

System

Component Parameter Normal Faulted (Blinking)

AFC 1 LEVEL 0 - 10.00 V N/A

PLL 1 CIRCUIT LOCKED UNLOCKED

ALC INPUT OK FAULT

Receiver Details

(Not used with

Digital.) FAULT AT 0 - 10.00 V FAULT

INPUT SIGNAL STATE OK FAULT

MODULATION OK FAULT

INPUT IF MODULATOR or J6 N/A

DLC CONTROL LOCK 0 - 5.00 V N/A

ALC LEVEL 0 - 5.00 V N/A

IF Processor

Details

ALC MODE AUTO or MANUAL N/A

AFC 1 LEVEL 0 – 5.00 V N/A

AFC 2 LEVEL 0 - 5.00 V N/A

CODE VERSION x.x N/A

PLL 1 CIRCUIT LOCKED FAULT

PLL 2 CIRCUIT LOCKED FAULT

AGC 1 LEVEL 0 - 5.00 V N/A

AGC 2 LEVEL 0 - 5.00 V N/A

Upconverter

Details

INT. 10 MHz IS USED N/A

System Control

Details SUPPLY ENABLED

FOR xxx HOURS N/A

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-13

System

Component Parameter Normal Faulted (Blinking)

POWER SUPPLY

STATE, 32V 32 VDC N/A

±12V SUPPLY OK or OFF FAULT

FORWARD POWER xxx% xxx%

REFLECTED POWER xxx% xxx%

AMP 1 CURRENT xx.xA xx.xA

AMP 2 CURRENT xx.xA xx.xA

TEMPERATURE xxC xxC

CODE VERSION x.x N/A

Exciter/Amplifier

Power Amplifier

Details

PA HAS OPERATED

FOR xxx HOURS N/A

Pushing the ↓ Down Arrow, after scrolling through all the detail screens, will put you back

to Menu 30, Table 3-10. Push the ESC button to exit the Transmitter Device Parameter

Screens to Menu 12, Table 3-7 to the Transmitter Device Parameter Access Screen.

Menu 40 (Table 3-13) is entered by selecting ENT at Menu 13.

Table 3-13: Menu 40 - Authorized Personnel Screen

This screen of the translator notifies an operator that they are only to proceed if they are

authorized to make changes to the translator's operation. Changes made within the

following set-up screens can affect the translators output power level, output frequency,

and the general behavior of the translator. Please do not make changes within the

translator's set-up screens unless you are familiar with the operation of the translator.

This screen is implemented in transmitter software version 1.4 and above.

Pressing ENT will put you into the Transmitter Set Up Screens for Menu 40.

A safeguard is added to the Set Up Menus in software version 2.5 and above. If a change

is made to a screen within the Set Up Menus, when you go to the next menu, a new

screen asks if you accept the change or want to return to the previous menu to

reconsider the changes made.

To accept the changes, the two buttons located under ACCEPT must be pushed

simultaneously.

To return to the previous Menu to make corrections, the two buttons located under the

RETURN must be pushed simultaneously.

Upon returning to the previous Menu the correct input must be entered and the above

procedure repeated, this time accepting the changes.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-14

Accept or Return to previous Menu Screen

Pushing these two buttons Pushing these two buttons

Simultaneously will accept Simultaneously will return you

the change. to the previous Menu.

The Set Up Screens are shown in Table 3-14 Menu 40-1 through Table 3-32 Menu 40-19

that follow.

Table 14: Menu 40-1 - Transmitter Set-up: Power Control Screen

This screen of the translator is the first of several that allows access to translator set-up

parameters. This is the output Power Control Screen. When + is selected, the Power will

increase. When - is selected, the Power will decrease.

Table 3-15: Menu 40-2 - Transmitter Set-up: Model Select Screen

This screen is used to specify which components are expected to be part of the system.

By specifying the model number, the transmitter control firmware knows which

components should be installed and it will be able to display faults for components that

are not properly responding to system commands.

Table 3-16: Menu 40-3 - Transmitter Set-up: Receiver Channel Configuration

This screen of the translator allows access to translator frequency set-up parameters.

The choices of this screen are as follow. NOTE: The above screen will only be present if a

Receiver is part of the system. Used to set the Receiver Channel designation and for

custom Channel Offsets the setting of the PLL operating frequency.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-15

Table 3-17: Menu 40-4 - Transmitter Set-up: Upconverter Channel Select Screen

The choices of this screen are to the standard UHF / VHF channels. The + and – buttons

change the desired channel of the translator. The PLL frequency is set for custom Offsets

within the upconverter frequency. Any change to the channel is immediately set to the LO

/ Upconverter Frequency Synthesizer PLL circuit.

Table 3-18: Menu 40-5 - Transmitter Set-up: Serial Address Screen

This screen allows the user to set the serial address of the translator. The default

address is 5. This value and all other set-up parameters, are stored in non-volatile

memory.

Table 3-19: Menu 40-6 - Transmitter Set-up: Station ID Screen

This screen allows the user to set the Station ID, Call Sign, in analog translators. If blank

characters are used for all five positions, then the Station ID feature is disabled.

Otherwise the Station ID code is transmitted every 15 minutes. This value and all other

set-up parameters, are stored in non-volatile memory. (NOTE: If an external Receiver

Tray is used in your system, the LX Series Station ID is disabled. Therefore, the Station

ID must be set up in the external Receiver Tray.)

Table 3-20: Menu 40-7 - Transmitter Set-up: System Visual Power Calibration

This screen is used to adjust the calibration of the system's visual power. A symbol

placed under the '6' character is used to show major changes in the calibration value.

When the calibration value is at full value, the character will be full black. As the value

decreases, the character pixels are gradually turned off. The calibration value is a value

between 0 and 255 but the calibration value symbol only has 40 pixels. Therefore small

changes in actual calibration value may not affect the symbol's appearance.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-16

Table 3-21: Menu 40-8 - Transmitter Set-up: System Aural Power Calibration

This screen is used to adjust the calibration of the system's aural forward power. A

calibration value symbol is used for this screen as on the previous screen.

Table 3-22: Menu 40-9 - Transmitter Set-up: System Reflected Power Calibration

This screen is used to adjust the calibration of the system's reflected power. Again a

calibration value symbol is used for this screen as on the previous screens.

Table 3-23: Menu 40-10 - Transmitter Set-up: Modulated Output Calibration

In analog systems, this screen is used to adjust the calibration of the system's modulated

output signal detector. The calibration value symbol is again used to graphically

represent the modulated output signal detector's calibration value.

Table 3-24: Menu 40-11 - Transmitter Set-up: Aural Deviation Calibration

In analog systems this screen is used to adjust the calibration of the system's aural

deviation detector. The calibration value symbol is again used to graphically represent

the aural deviation detector's calibration value.

Table 3-25: Menu 40-12 - Transmitter Set-up: Forward Power Fault Threshold Screen

This screen is used to set the minimum forward power fault threshold. When the

translator is operating, it must operate above this value otherwise the system will shut

down with fault for 5 minutes. If after five minutes the fault is not fixed, the translator

will enable, measure power less than this value and again shut down for five minutes.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-17

Table 3-26: Menu 40-13 - Transmitter Set-up: Reflected Power Fault Threshold

This screen is used to set the maximum reflected power fault threshold. When the

translator is operating, it must not operate above this value otherwise the system will

slowly begin to reduce the forward output power. If the system's reflected output power

exceeds the maximum reflected power threshold by five percent or more, the translator

will shut down with fault for 5 minutes. If after five minutes the fault is not fixed, the

translator will enable, measure power above this value plus five percent and again shut

down for five minutes. If the system's reflected output power exceeds the maximum

reflected power threshold due to some condition like the formation of ice on an antenna,

the translator reduces forward power to a level where the reflected power is less than

this threshold. The translator will automatically increase its output power to normal

operation when the cause of higher than normal reflected power is corrected.

Table 3-27: Menu 40-14 - Transmitter Set-up: Auto Stand-By Control

Certain LX translator locations are required to reduce to no output power on the loss of

video input. When a LX translator is configured for Auto Stand-By On Modulation Loss,

the translator will switch to stand-by, if a modulated input signal fault is detected by the

IF Processor module that lasts for more than ten seconds. Once the modulated input

signal fault is cleared, a translator in operate mode will return to normal operation. This

feature is implemented in transmitter software version 1.4 and above.

Table 3-28: Menu 40-15 - Transmitter Set-up: Receiver ALC Fault Set Up

This screen is used to set up the level of the ALC at which the Receiver will fault. This

feature is implemented in transmitter software version 2.0 and above. NOTE: The above

screen will only be present if a Receiver is part of the system.

Table 3-29: Menu 40-16 - Transmitter Set-up: Inner Loop Gain Control

This screen is used to set up the Inner Loop Gain of the exciter/amplifier assembly. This

feature is implemented in transmitter software version 2.0 and above.

LX Series VHF Translator Chapter 3, Site Considerations,

Installation and Setup Procedures

LX Series, Rev. 0 3-18

Table 3-30: Menu 40-17 - Transmitter Set-up: Optional System Control

This screen is used to set up any optional system, including the addition of the optional

Modulator in a translator system. This feature is implemented in transmitter software

version 2.0 and above.

Table 3-31: Menu 40-18 - Transmitter Set-up: Amplifier Output Power Warning

This screen is used to set up the Amplifier Output Power level at which a warning will be

sent out if the power output of the amplifier drops below this setting. The warning

indication is the blinking of the Module OK LED colored Amber, located on the front of the

amplifier module. (NOTE: Only in Amplifier Code Versions 3.7A or later and System

Controller Code Versions 3.9C or later.)

Table 3-32: Menu 40-19 - Transmitter Set-up: Remote Commands Control

This screen is used to allow or deny the use of remote control commands. When

disabled, remote commands are not used. Remote commands are commands received

either through the rear terminal blocks or through serial messages. Push the ESC button

to exit the Transmitter Set Up Screens to Menu 13, Table 3-8, the Transmitter

Configuration Access Screen.

This completes the description of the menu screens for the LX Series exciter/driver chassis

assembly.

3.5.5 Operation Procedure

If necessary, place the translator in

standby and connect the translator to

the antenna. Switch the translator to

operate and check that the output is

100% and if needed adjust the ALC

Gain adjust pot on the front panel of

the IF Processor to attain 100%. The

power raise / lower settings, in the

menus, are only to be used for

temporary reductions in power.

The power set-back values do not

directly correspond to the output power

of the translator.

This completes the Installation, Set Up

and Turn On of the Translator. If a

problem occurred during the setup and

operation procedures, refer to Chapter

5, Detailed Alignment Procedures, of

this manual for more information.

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-1

Chapter 4

Circuit Descriptions

4.2 (A1) Receiver Module, VHF High

Band (1304001; Appendix A)

NOTE: Used in analog translator system.

4.2.1 IF ALC Board (1304003;

Appendix A)

The board provides the interface between

the receiver and the backplane and also

contains the control and ALC circuits for

the sled.

The control portion of the board consists

of a microcontroller (U8) and its

associated components that

communicate to the outside world via an

RS-485 serial data link. The

microcontroller receives various metering

and alarm functions such as AFC and ALC

voltages, PLL and ALC faults and

communicates them back to the system

controller for display on the transmitter’s

LCD display. It also receives the channel

information from the system controller,

and converts it to the programming data

for the PLL chip on the Mixer/PLL Board

in the receiver.

The IF portion of the board consists of

an input pin attenuator, which is used to

normalize the gain of the board to

account for variations in the input level

to the board. The pin attenuator is

made up of DS1, DS2 and associated

components. The signal is then amplified

by U2-U4 and associated components

and applied to a SAW filter that rejects

any out of channel signal that made it

through the receivers RF front end.

Amplifiers U5, U6 and their associated

components are used to amplify the

signal to make up for the loss through

the filter. The final output of U6 is split

by a lumped element Wilkinson splitter

consisting of C21, C26, C27, L12, and

L14. The output from one of the output

ports is sent to the output of the

receiver, and the other output is

connected to a peak detector and used

by the ALC. The ALC circuit, consisting of

U1, CR4 and its associated components,

varies the gain of the pin attenuator on

the front end of the board to maintain a

constant output level. The pin attenuator

has an overall adjustment range of

approximately 50 dB.

There is a comparator that looks at the

pin attenuator voltage and generates an

alarm if the pin attenuator is close to

running out of range. This alarm is likely

to occur if the RF input signal to the

receiver is weak or missing. This alarm is

received by the microcontroller that

passes it along to the transmitter's system

controller, which mutes the signal in the

IF processor until the fault goes away.

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-2

4.2.2 VHF Mixer/PLL Board

(1306472; Appendix A)

The VHF Mixer/PLL Board converts the

RF input to the receiver to a 44 MHz IF.

It consists of a Mixer, a local oscillator

and some IF amplifiers used to make up

for the loss of the mixer.

The Local oscillator signal is generated

by the VCO (U3), which operates directly

at the LO frequency of the VHF channel

center frequency (104-176 MHz) + 44

MHz. The oscillator is phase locked to a

10 MHz standard by U2, U8, and their

associated components. TP1 shows the

AFC voltage, which is also sent back to

the IF ALC board to be displayed on the

system level controller. The variable

resistor R30 sets the LO output level to

+10 dBm into the mixer U4. This is

done by looking at the LO sample at J2

with a spectrum analyzer, adjusting R30

until the level is -10 dBm. This ensures

that the mixer gets the correct level, as

the sample is 20 dB down from the level

into the mixer.

Mixer U4 converts the RF input at J1 to

an IF frequency of 44 MHz. L13, L14

and C56 form a low pass filter, which

rejects any unwanted higher frequency

conversion products. U5 and U9 amplify

the signal, which exits the board at J5.

There are two jumpers on J3 and J4 that

allow the user to switch in a 10 dB

attenuator if the input level to the

receiver is too high. Normally the

jumpers are connected between pins 1

and 2 of each connector, but if the user

has a high input level, they can be

switched to connect pins 2 and 3 of each

connector, which switches in the 10 dB

pad.

The A/V ratio of the incoming signal can

be adjusted via an external front panel

pot, which controls the bias on pin

attenuator DS3. The pin attenuator

controls the Q of a notch set at the aural

IF carrier frequency, set by C41 and L7.

The A/V ratio control is used if the

incoming signal has an aural carrier that is

too high relative to the visual carrier.

4.2.3 VHF High Band Preamplifier

Board (1306445; Appendix A)

The VHF High Band Preamplifier Board

filters and amplifies the low level RF input

signal to the receiver. It consists of two

two-pole bandpass filters and a dual stage

preamplifier. The filters are tuned at the

RF channel frequency and are about 8

MHz wide. They are intended to filter off

the unwanted image product 88 MHz

below the Channel center frequency.

Each filter is a combination micro-strip

lumped element filter.

The input filter also has provisions to

insert a +12V DC signal onto the center

conductor of the receiver's RF input to

power an external preamp. The jumper

W1 on J2 controls whether or not the DC

bias is applied to the center conductor.

When it is connected between pins 1 and

2, the +12V bias is applied. When it is

between pins 2 and 3, there is no bias

applied. The presence of the DC bias is

displayed on a front panel LED on the

sled.

CAUTION: Do not hook up the RF

input to any test equipment with the

DC bias applied. Always move the

jumper W1 on J2 to the Bias off

position, between pins 2 & 3, to

prevent possible damage to the test

equipment.

The amplifier consists of two cascaded

stages, which provide approximately 27

dB of gain across the VHF High Band

channels.

4.3 (A3) IF Processor Module

Assembly (1301938; Appendix A)

The IF from the modulator enters the

module and the signal is pre-corrected as

needed for amplitude linearity correction,

Incidental Carrier Phase Modulation

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-3

(ICPM) correction and frequency

response correction.

The Module contains the IF Processor

board 1301977.

4.3.1 IF Processor Board (1301977;

Appendix A)

The automatic level control (ALC) portion

of the board provides the ALC and

amplitude linearity correction of the IF

signal. The ALC adjusts the level of the

IF signal that controls the output power

of the transmitter.

The IF from the modulator enters the

board at J42 pin 32B. If the (optional)

receiver is present, the IF input (-6 dBm)

from the receiver connects to the

modulated IF input jack J42 Pin 21C.

The modulator IF input connects to relay

K3 and the receiver IF input connects to

relay K4.

The Modulator select enable/disable

jumper W11 on J29 controls whether the

Modulator Select command at J42 Pin

14C controls the operation of the relays.

With the jumper W11 on J29 between

pins 1 and 2, the external Modulator

Select command at J42 Pin 14C controls

the operation of the relays. With the

jumper W11 on J29 between pins 2 and

3, the Modulator input is selected all of

the time.

4.3.1.1 Modulator Selected

With the modulator selected, J42-14C

low or the jumper W11 on J29 between

pins 2 and 3, the low shuts off Q12 and

causes Pin 8 on the relays to go high that

causes relays K3 and K4 to de-energize.

When K4 is de-energized, it connects the

receiver IF input at J42-21C, if present,

to a 50O load. When K3 is de-energized,

it connects the modulator IF input at J42-

32B to the rest of the board and the

Modulator Enable LED DS5 will be

illuminated.

4.3.1.2 External Modulated IF Selected

With the External Modulated IF selected,

J42-14C high and jumper W11 on J29

between pins 1 and 2, this high turns on

Q12 and makes pin 8 on the relays Low

that causes the relays K3 and K4 to

energize. When K4 is energized, it

connects the receiver IF input at J42-21C,

if present, to the rest of the board. When

K3 is energized, it connects the modulator

IF input at J42-32B to a 50O load and the

Modulator Enable LED DS5 will not be

illuminated.

4.3.1.3 Main IF Signal Path (Part 1 of 3)

The selected IF input (-6 dBm average)

signal is split, with one half entering a

bandpass filter that consists of L3, L4, C4,

L5, and L6. This bandpass filter can be

tuned with C4 and is substantially broader

than the IF signal bandwidth. It is used to

slightly steer the frequency response of the

IF to make up for any small discrepancies

in the frequency response in the stages

that precede this point. The filter also

serves the additional function of rejecting

unwanted frequencies that may occur if the

tray cover is off and the tray is in a high RF

environment. (If this is the case, the

transmitter will have to be serviced with

the tray cover off in spite of the presence

of other RF signals). The filtered IF signal is

fed through a pi-type matching pad

consisting of R2, R3, and R4 to the pin-

diode attenuator circuit consisting of CR1,

CR2, and CR3.

4.3.1.4 Input Level Detector Circuit

The other part of the split IF input is

connected through L2 and C44 to U7. U7

is an IC amplifier that is the input to the

input level detector circuit. The amplified IF

is fed to T4, which is a step-up transformer

that feeds diode detector CR14. The

positive-going detected signal is then low-

pass filtered by C49, L18, and C50. This

allows only the positive digital peaks to be

applied through emitter follower Q1. The

signal is then connected to detector CR15

to produce a peak digital voltage that is

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-4

applied to op-amp U9A. There is a test

point at TP3 that provides a voltage-

reference check of the input level. The

detector serves the dual function of

providing a reference that determines the

input IF signal level to the board and also

serves as an input threshold detector.

The input threshold detector prevents the

automatic level control from reducing the

attenuation of the pin-diode attenuator to

minimum, the maximum signal output, if

the IF input to the board is removed. The

ALC, input loss cutback, and the

threshold detector circuits will only

operate when jumper W2 on jack J5 is in

the Enabled position, between pins 2 and

3. Without the threshold detector, and

with the pin-diode attenuator at

minimum, the signal will overdrive the

stages following this board when the

input is restored.

As part of the threshold detector

operation, the minimum IF input level at

TP3 is fed through detector CR15 to op-

amp IC U9A, pin 2. The reference

voltage for the op-amp is determined by

the voltage divider that consists of R50

and R51, off the +12 VDC line. When

the detected input signal level at U9A,

pin 2, falls below this reference

threshold, approximately 10 dB below

the normal input level, the output of U9A

at pin 1 goes high, toward the +12 VDC

rail. This high is connected to the base

of Q2 that is forward biased and creates

a current path. This path runs from the -

12 VDC line, through red LED DS1, the

input level fault indicator, which lights,

resistor R54, and transistor Q2 to +12

VDC. The high from U9A also connects

through diode CR16 and R52, to U24D

pin 12, whose output at pin 14 goes high.

The high connects through the front

panel accessible ALC Gain pot R284 and

the full power set pot R252 to U24C Pin

9. This high causes U24C pin 8 to go

low. A power raise/lower input from the

Control/Monitoring Module connects to

J42C pin 24C and is wired to Q14. This

input will increase or decrease the value

of the low applied to U24B and therefore

increase or decrease the power output of

the transmitter.

The low connects to U24B pin 5 whose

output goes low. The low is wired to U24A

pin 2 whose output goes high. The high is

applied to U10A, pin 2, whose output goes

low. The low connects through the switch

SW1, if it is in the auto gain position, to

the pin-diode attenuator circuit, CR1, CR2

& CR3. The low reverse biases them and

cuts back the IF level, therefore the output

level, to 0. When the input signal level

increases above the threshold level, the

output power will increase, as the input

level increases, until normal output power

is reached.

The input level at TP3 is also fed to a pulse

detector circuit, consisting of IC U8, CR17,

Q3, and associated components, and then

to a comparator circuit made up of U9C

and U9D. The reference voltage for the

comparators is determined by a voltage

divider consisting of R243, R65, R66, and

R130, off the -12 VDC line. When the input

signal level to the detector at TP3 falls

below this reference threshold, which acts

as a loss-of-signal peak detector circuit,

the output of U9C and U9D goes towards

the -12 VDC rail and is split, with one part

biasing on transistor Q5. A current path is

then established from the +12 VDC line

through Q5, the resistors R69 and R137,

and the red LED DS3, input loss indicator,

which is illuminated. When Q5 is on, it

applies a high to the gate of Q6. This

causes it to conduct and apply a

modulation loss pull-down output to J42C,

pin 7C, which is applied to the front panel

display on the Control/Monitor module.

The other low output of U9C and U9D is

connected through CR18, CR19 & CR20 to

jack J5. Jumper W2 on J5, in the Cutback

Enable position, which is between pins 2

and 3, connects the low to the base of Q4

that is now forward-biased. NOTE: If

jumper W2 is in the Disable position,

between pins 1 and 2, the auto cutback will

not operate. With Q4 biased on, a

negative level determined by the setting of

cutback level pot R71 is applied to U24D,

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-5

pin 12. The level is set at the factory to

cut back the output to approximately

25%. The output of U24D at pin 14 goes

low and is applied through the power

adjust pot to U24C, pin 9, whose output

goes low. The low connects to U24B, pin

5, whose output goes low. The low then

connects to U24A, pin 2, whose output

goes high. The high is applied to U10A,

pin 2, whose output goes low. The low

connects through the switch SW1, if it is

in the auto gain position, to the pin-diode

attenuator circuit, CR1, CR2 & CR3. The

low reverse biases them and cuts back

the level of the output to approximately

25%.

4.3.1.5 Pin-Diode Attenuator Circuit

The input IF signal is fed to a pin-diode

attenuator circuit that consists of CR1,

CR2 & CR3. Each of the pin diodes

contains a wide intrinsic region; this

makes the diodes function as voltage-

variable resistors at this intermediate

frequency. The value of the resistance is

controlled by the DC bias supplied to the

diode. The pin diodes are configured in a

pi-type attenuator configuration where

CR1 is the first shunt element, CR3 is the

series element, and CR2 is the second

shunt element. The control voltage,

which can be measured at TP1, originates

either from the ALC circuit when the

switch SW1 is in the ALC Auto position,

between pins 2 and 3, or from pot R87

when SW1 is in the Manual Gain position,

between pins 1 and 2.

In the pin diode attenuator circuit,

changing the amount of current through

the diodes by forward biasing them

changes the IF output level of the board.

There are two extremes of attenuation

ranges for the pin-diode attenuators. In

the minimum attenuation case, the

voltage, measured at TP1, approaches

the +12 VDC line. There is a current path

created through R6, through series diode

CR3, and finally through R9 to ground.

This path forward biases CR3 and causes

it to act as a relatively low-value resistor.

In addition, the larger current flow

increases the voltage drop across R9 that

tends to turn off diodes CR1 and CR2 and

causes them to act as high-value resistors.

In this case, the shunt elements act as a

high resistance and the series element acts

as a low resistance to represent the

minimum loss condition of the attenuator

(maximum signal output). The other

extreme case occurs as the voltage at TP1

is reduced and goes towards ground or

even slightly negative. This tends to turn

off (reverse bias) diode CR3, the series

element, causing it to act as a high-value

resistor. An existing fixed current path

from the +12 VDC line, and through R5,

CR1, CR2, and R9, biases series element

CR3 off and shunt elements, diodes CR1

and CR2, on, causing them to act as

relatively low-value resistors. This

represents the maximum attenuation case

of the pin attenuator (minimum signal

output). By controlling the value of the

voltage applied to the pin diodes, the IF

signal level is maintained at the set level.

4.3.1.6 Main IF Signal Path (Part 2 of 3)

When the IF signal passes out of the pin-

diode attenuator through C11, it is applied

to the modular amplifier U1. This device

contains the biasing and impedance-

matching circuits that makes it operate as

a wide-band IF amplifier. The output of U1

connects to J40 that is jumpered to J41.

The J40 jack is available, as a sample of

the pre-correction IF for troubleshooting

purposes and system setup. The IF signal

is connected to a splitter Z1 that has an In

Phase output and a 90° Quadrature output,

which are then connected to the linearity

corrector portion of the board.

4.3.1.7 Amplitude and Phase

Pre-Correction Circuits

The linearity corrector circuits use three

stages of correction, two adjust for any

amplitude non-linearities and one for phase

non-linearities of the output signal. Two of

the stages are in the In Phase Amplitude

pre-correction path and one stage is in the

Quadrature Phase pre-correction path.

Each stage has a variable threshold control

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-6

adjustment, R211 and R216, in the In

Phase path, and R231, in the Quadrature

path, that determines the point at which

the gain is changed for that stage.

Two reference voltages are needed for

the operation of the corrector circuits.

The Zener diode VR3, through R261,

provides the +6.8 VDC reference. The

VREF is produced using the path through

R265 and the diodes CR30 and CR31.

They provide a .9 VDC reference, which

temperature compensates for the two

diodes in each corrector stage.

The first corrector stage in the In Phase

path operates as follows. The In Phase

IF signal is applied to transformer T6,

which doubles the voltage swing by

means of a 1:4 impedance

transformation. Resistors R222 and

R225 form an L-pad that lowers the level

of the signal. The input signal level,

when it reaches a set level, causes the

diodes CR24 and CR25 to turn on,

generating current flow that puts them in

parallel with the L-pad. When the diodes

are put in parallel with the resistors, the

attenuation through the L-pad is lowered,

causing signal stretch.

The signal is next applied to amplifier

U17 to compensate for the loss through

the L-pad. The breakpoint, or cut-in

point, for the first corrector is set by

controlling where CR24 and CR25 turn

on. This is accomplished by adjusting the

threshold cut-in resistor R211. R211

forms a voltage-divider network from

+6.8 VDC to ground. The voltage at the

wiper arm of R211 is buffered by the

unity-gain amplifier U16B. This reference

voltage is then applied to R215, R216,

and C134 through L44 to the CR24 diode.

C134 keeps the reference from sagging

during the vertical interval. The .9 VDC

reference voltage is applied to the unity-

gain amplifier U16D. The reference

voltage is then connected to diode CR25

through choke L45. The two chokes L44

and L45 form a high impedance for RF

that serves to isolate the op-amp ICs

from the IF.

After the signal is amplified by U17, it is

applied to the second corrector stage in the

In Phase path through T7. These two

correctors and the third corrector stage in

the Quadrature path operate in the same

fashion as the first. All three corrector

stages are independent and do not interact

with each other.

The correctors can be disabled by moving

the jumper W12 on J30 to the Disable

position, between pins 1 and 2, this moves

all of the breakpoints past the signal peaks

so that they will have no affect.

The pre-distorted IF signal in the In Phase

path, connects to an op amp U18 whose

output level is controlled by R238. R238

provides a means of balancing the level of

the amplitude pre-distorted IF signal that

then connects to the combiner Z2.

The pre-distorted IF signal in the

Quadrature path connects to op amp U20

and then step up transformer T9, next op

amp U21 and step up transformer T10 and

finally op amp U22 whose output level is

controlled by R258. R258 provides a

means of balancing the level of the Phase

pre-distorted IF signal that then connects

to the combiner Z2.

The Amplitude and Phase pre-distorted IF

signals are combined by Z2 and connected

to J37 that is jumpered to J36 on the

board. J37 can be used for testing or

monitoring purposes of the IF signal after

Amplitude and Phase pre-distortion. The

pre-distorted IF signal connects through a

resistor buffer network that prevents

loading of the combiner before it is wired

to the frequency response circuitry.

4.3.1.8 Main IF Signal Path (Part 3 of 3)

The IF signal, at the input to the

frequency-response corrector circuit, is

split using L24, L25 and R89. One path is

through L24, which is the main IF path

through the board. The main IF is fed

through a resistor network that controls

the level of the IF by adjusting the

resistance of R99, the output level adjust.

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-7

The IF signal is then applied to a three-

stage, frequency-response corrector

circuit that is adjusted as needed.

The frequency-response corrector circuit

operates as follows. Variable resistors

R103, R106 and R274 are used to adjust

the depth and gain of the notches and

variable caps C71, C72 and C171 are

used to adjust the frequency position of

the notches. These are adjusted as

needed to compensate for frequency

response problems.

The frequency-response corrected IF is

connected to J38 that is jumpered to J39

on the board. J38 can be used for

testing or monitoring purposes of the IF

signal after frequency response pre-

correction.

The IF is next amplified by U13 and U14.

After amplification, the IF is split with one

path connected to J42C pin 1C the IF

output to the LO/Upconverter Module.

The other path is fed through a divider

network to J35 a SMA IF Sample Jack,

located on the front panel, which

provides a sample of the corrected IF for

test purposes.

4.3.1.9 ALC Circuit

The other path of the corrected IF signal

at the input to the frequency response

corrector circuit is used in the ALC circuit.

The IF flows through L25, of the L24 L25

splitter, and connects to the op-amp

U12. The IF signal is applied through a

resistor divider network to transformer

T5. T5 doubles the voltage swing by

means of a 1:4 impedance

transformation before it is connected to

the ALC detector circuit, consisting of

C70, CR23 and R91. The detected ALC

level output is amplified by U10B and

wired to U10A, pin 2, where it is summed

with the power control setting, which is

the output power setting that is

maintained by the ALC. The output of

U10A connects through SW1, if it is in

the auto gain position, to the pin-diode

attenuator circuit, CR1, CR2 & CR3. The

high forward biases them more or less,

that increases or decreases the IF level,

therefore the output level, opposite the

input level. When the input signal level

increases, the forward bias on the pin

attenuator decreases, therefore the output

power will decrease, which keeps the

output power the same as set by the

customer.

An external power raise/lower switch can

be used by connecting it to TB30, at TB30-

8 power raise and TB30-9 power lower, on

the rear of the exciter/amplifier chassis.

The ALC voltage is set for .8 VDC at TP4

with a 0-dBm output at J42C pin 1C of the

module. A sample of the ALC at J42C pin

11C, is wired to the Control

Monitoring/Power Supply module where it

is used on the LCD display and in the AGC

circuits.

The ALC voltage, and the DC level

corresponding to the IF level after signal

correction, are fed to U10A, pin 2, whose

output at pin 1 connects to the ALC pin-

diode attenuator circuit. If there is a loss of

gain somewhere in an IF circuit, the output

power of the transmitter will drop. The ALC

circuit senses this drop at U10A and

automatically decreases the loss through

the pin-diode attenuator circuit therefore

increasing its gain maintaining the same

output power level.

The ALC action starts with the ALC detector

level monitored at TP4. The detector

output at TP4 is nominally +.8 VDC and is

applied through resistor R77 to a summing

point at op-amp U10A, pin 2. The current

available from the ALC detector is offset, or

complemented, by current taken away

from the summing junction. In normal

operation, U10A, pin 2, is at 0 VDC when

the loop is satisfied. If the recovered or

peak-detected IF signal level at IF input to

this board should drop, which normally

means that the output power will decrease,

the null condition would no longer occur at

U10A, pin 2. When the level drops, the

output of U10A, pin 1, will go more

positive. If SW1 is in the Automatic

position, it will cause the ALC pin-diode

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-8

attenuators CR1, CR2, and CR3 to have

less attenuation and increase the IF

level; this will compensate for the

decrease in the level. If the ALC cannot

increase the input level enough to satisfy

the ALC loop, due to the lack of range, an

ALC fault will occur. The fault is

generated because U10D, pin 12,

increases above the trip point set by R84

and R83 until it conducts. This makes

U10D, pin 14, high and causes the red

ALC Fault LED DS2 to light.

4.3.1.10 Fault Command

The board also has circuitry for an

external mute fault input at J42 pin 10C.

This is a Mute command that protects the

circuits of high-gain output amplifier

devices against VSWR faults. This action

needs to occur faster than just pulling

the ALC reference down. Two different

mechanisms are employed: one is a very

fast-acting circuit to increase the

attenuation of the pin-diode attenuator,

CR1, CR2, and CR3, and the second is

the reference voltage being pulled away

from the ALC amplifier device. An

external Mute is a pull-down applied to

J42 pin 10C, which completes a current

path from the +12 VDC line through R78

and R139, the LED DS4 (Mute indicator),

and the LED section of opto-isolator U11.

These actions turn on the transistor

section of U11 that applies -12 VDC

through CR21 to U10A pin 3, and pulls

down the reference voltage. This is a

fairly slow action controlled by the low-

pass filter function of R81 and C61.

When the transistor section of U11 is on,

-12 VDC is also connected through CR22

directly to the pin-diode attenuator

circuit. This establishes a very fast

muting action, by reverse biasing CR3.

This action occurs in the event of an

external VSWR fault.

4.3.1.11 ±12 VDC Needed to Operate the

Board

The ±12 VDC connects to the board at

J42C. The +12 VDC connects to J42C pin

16C and is filtered by L30, L41, and C80

before it is applied to the rest of the board.

The -12 VDC connects to J42C pin 18C and

is filtered by L31 and C81 before it is

applied to the rest of the board.

The +12 VDC connects through R261 to

the zener diode VR3 that connects to

ground, which generates the +6.8 VDC

output to the rest of the board. The +12

VDC also connects through R265 to the

diodes CR30 and CR31 provide a .9 VDC

reference output voltage VREF that

temperature compensates for the two

diodes in each corrector stage.

4.4 (A5) VHF/UHF Upconverter

Module (1303829; Appendix A)

This module contains the Downconverter

Board Assembly 1303834, the First

Conversion Board 1303838, L-Band PLL

Board 1303846 and the Upconverter

Control Board 1304760. This module

takes an external IF and converts it to the

final RF output frequency using two

internally generated local oscillator

frequencies.

4.4.1 (A1) Downconverter Board

Assembly (1303834; Appendix A)

This board converts a signal at an input

frequency of 1044 MHz to a broadcast VHF

or UHF TV channel.

The IF at 1044MHz is applied to the board

at J7, and is converted down to VHF or

UHF by the mixer IC U6. The LO

frequency is applied to the board at a

level of +20 dBm at J8. The output of the

mixer is applied to a 6 dB attenuator and

then to a 900 MHz Low Pass filter. The

filter is intended to remove any unwanted

conversion products. The signal is next

connected to the amplifier U2, and then a

pin diode attenuator consisting of DS4,

DS5 and their associated components.

The attenuator sets the output level of the

board and is controlled either by a manual

gain pot R7, or an external AGC circuit.

This automatic or manual mode of

operation is controlled by the switch SW1.

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-9

When in manual mode, the LED DS6 is

illuminated.

The output of the pin attenuator is

applied to another amplifier U3 and

another low pass filter, before reaching

the final amplifier U1. The output of the

board is at J5 with a sample of the

output available at J6, which is 20 dB in

level below the signal at J5.

4.4.2 (A2) L-Band PLL Board

(1303846; Appendix A)

This board generates an LO at a

frequency of 1.1-1.9 GHz. The board

contains a PLL IC U6, which controls the

output frequency of a VCO. The PLL IC

divides the output of the VCO down to

100kHz, and compares it to a 100kHz

reference created by dividing down an

external 10 MHz reference that is

applied to the board at J1 pin 4. The IC

generates an error current that is

applied to U3 and its associated

components to generate a bias voltage

for the VCO's AFC input.

There are two VCOs on the board, U4,

which operates at 1.1-1.3 GHz for VHF

channels, and U5, which operates at

1.5-1.9 GHz for UHF channels. The VCO

in use is selected by a signal applied to

J1 pin 20. This input enables the power

supply either U1 or U2 for the

appropriate VCO for the desired channel.

U7 is a power supply IC that generates

+5V for the PLL IC U6.

The output of each VCO is filtered by a

low pass filter to remove any harmonic

content and applied to a pin diode

switch consisting of CR1, CR2, and their

associated components. The selected

signal is amplified by U9 and U10, then

applied to a high pass filter and finally

amplified to a level of approximately

+21 dBm by U11. The output is

connected to a low pass filter to remove

any unwanted harmonic content and

leaves the board at J3 at a level of +20

dBm.

4.4.3 (A3) First Conversion Board

(1303838; Appendix A)

This board generates a 1 GHz LO signal

using the VCO U9, the PLL IC U12, and

the loop filter, C30-C33 and R49. The PLL

IC compares a divided down sample of the

VCO to a divided down sample of the

transmitter's system 10 MHz reference.

The output of the VCO is amplified by U10

and U11 and applied to a low pass filter

before being connected to an image

rejection mixer consisting of U1, U2, U3

and U6. The 44 MHz IF input is connected

to the board at J2, and then to the image

rejection mixer. This mixer converts the

44 MHz input to an output frequency of

1044 MHz. The output of the mixer is

amplified by U4 and applied to a band

pass filter consisting of C2-C4 and some

microstrip line sections. This filter rejects

any LO leakage at 1 GHz and also any

unwanted out of band products. The

output of the filter is amplified by U5 and

then filtered before exiting the board at

J1.

4.4.4 (A4) Upconverter Control Board

(1304760; Appendix A)

This board performs a variety of functions,

which include an interface between the

other boards in the upconverter and the

rest of the transmitter. It also has a

microcontroller U8, which controls and

monitors the functions of the other boards

in the assembly.

The microcontroller communicates via an

RS-485 interface with the transmitter's

system control module. It reports any

faults and metering information and

receives channel information, which it

passes along to the PLLs on the L-Band

PLL Board and the First Conversion Board.

The board also generates various voltages

used by the rest of the boards in the

upconverter. U9 converts the +12V input

to the board to +20V. U15 converts +12V

to +5V for the on board 10 MHz crystal

oscillator. U12 converts +12V to +9V for

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-10

the L-Band PLL board and the First

Conversion board. U13 and U14

generate +5V for the microcontroller.

The board also selects whether the

internal or external 10 MHz reference

source will be used. There is an

onboard 10 MHz oscillator, U3, which is

used when no external 10 MHz source is

present. The Relay K1 is automatically

switched to the external 10 MHz

reference whenever it is present. The

LED DS1 illuminates whenever the

internal 10 MHz reference is used. The

diode detector CR1 detects the presence

of the 10 MHz external reference that

connects to U2, which compares the

detected level to a reference level and

switches the relay whenever the

reference is present. It also disables the

internal oscillator whenever the external

10 MHz reference is being used.

The output of the relay is split to drive

multiple outputs, some internal and

some external. The external outputs

leave the board at J1-22C and J1-31B

and are used by the external receiver

and modulator modules.

The board also contains AGC circuitry,

which controls a pin diode attenuator on

the Downconverter Board. There are

three references used by the AGC

circuit. The first is the AGC reference

#1, which comes from the transmitter's

driver module. The second is the AGC

reference #2, which is a diode ORed

sample of the output stages of the

transmitter. The IC U5 normalizes the

level of the AGC reference # 1 and sets

it at a level that is 0.2V less than the

level of AGC reference #2. The AGC

reference #1 and #2 are diode ORed

with only the highest reference used by

the AGC circuit.

The highest reference is compared to

the ALC reference, which originated on

the IF processor module, and the error

voltage generated by U4D and applied

to the external pin attenuator. The AGC

will try to maintain a constant ratio

between the ALC voltages and the higher

of the two AGC voltages. If something in

the output amplifier of the transmitter

fails, the AGC reference #1 voltage will

take over and the power will be regulated

at the output of the driver.

The RF from the Upconverter Module

Assembly connects from the Upconverter RF

Output BNC Jack J23, through a cable, to

the PA RF Input BNC Jack J24, located on

the rear of the exciter/amplifier chassis

assembly.

4.5 (A4) Control Monitoring/Power

Supply Module, 110 VAC

(1301936; Appendix A)

The Control Monitoring/Power Supply

Module Assembly contains (A1) a Power

Protection Board (1302837), (A2) a 600

Watt Switching Power Supply, (A3) a

Control Board (1302021), (A4) a Switch

Board (1527-1406) and (A5) a LCD

Display.

AC Input to Innovator LX Exciter/Amplifier

Chassis Assembly

The AC input to the Exciter/Amplifier

Chassis Assembly is connected from J1,

part of a fused entry module, located on

the rear of the chassis assembly to J50 on

the Control Monitoring/Power Supply

Module. J50-10 is line #1 input, J50-8 is

earth ground and J50-9 is line #2 input.

The input AC connects to J1 on the Power

Protection Board where it is fuse protected

and connected back to J50, at J50-11 AC

Line #1 and J50-12 AC Line #2, for

distribution to the cooling Fan.

4.5.1 (A1) Power Protection Board

(1302837; Appendix A)

The input AC connects through J1 to two

10 Amp AC fuses F1 and F2. The AC line

#1 input connects from J1-1 to the F1

fuse. The AC line #1 input after the F1

fuse is split with one line connected back

to Jack J1 Pin 4, which becomes the AC

Line #1 to the Fan. The other line of the

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-11

split connects to J4. The AC line #2

input connects from J1-3 to the F2 fuse.

The AC line #2 input after the F2 fuse is

split with one line connected back to

Jack J1 at Pin 5, which becomes the AC

Line #2 to the Fan. The other line of the

split connects to J2. J1-2 is the earth

ground input for the AC and connects to

J3.

Three 150 VAC MOVs are connected to

the input AC for protection. One

connects from each AC line to ground

and one connects across the two lines.

VR1 connects from J4 to J2, VR2

connects from J4 to J3 and VR3 connects

from J2 to J3.

4.5.1.1 +12 VDC Circuits

+12 VDC from the Switching Power

Supply Assembly connects to J6 on the

board. The +12 VDC is divided into four

separate circuits each with a 3 amp self

resetting fuse, PS3, PS4, PS5 and PS6.

The polyswitch resettable fuses may

open on a current as low as 2.43 Amps

at 50°C, 3 Amps at 25°C or 3.3 Amps at

0°C. They definitely will open when the

current is 4.86 Amps at 50°C, 6 Amps

at 25°C or 6.6 Amps at 0°C.

PS3 protects the +12 VDC 2 Amp

circuits for the System Controller, the

Amplifier Controller and the Spare Slot

through J62 pins 7, 8, 9 and 10. If this

circuit is operational, the Green LED

DS3, mounted on the board, will be lit.

PS4 protects the +12 VDC 2 Amp

circuits for the Modulator and the IF

Processor through J62 pins 13, 14, 15

and 16. If this circuit is operational, the

Green LED DS4, mounted on the board,

will be lit

PS5 protects the +12 VDC 2 Amp

circuits for the Upconverter through J62

pins 17, 18, 19 and 20. If this circuit is

operational, the Green LED DS5,

mounted on the board, will be lit

PS6 protects the +12 VDC 2 Amp circuits

for the Remote through J63 pins 17, 18,

19 and 20. If this circuit is operational,

the Green LED DS6, mounted on the

board, will be lit

4.5.1.2 -12 VDC Circuits

-12 VDC from the Switching Power Supply

Assembly connects to J5 on the board.

The -12 VDC is divided into two separate

circuits each with a 3 amp self resetting

fuse, PS1 and PS2.

PS1 protects the -12 VDC 2 Amp circuits

for the System through J63 pins 1, 2, 3

and 4. If this circuit is operational, the

Green LED DS1, mounted on the board,

will be lit

PS2 protects the -12 VDC 2 Amp circuits

for the Remote through J62 pins 1, 2, 3

and 4. If this circuit is operational, the

Green LED DS2, mounted on the board,

will be lit

The connections from J62 and J63 of the

Power Protection Board are wired to J62

and J63 on the Control Board.

4.5.2 (A3) Control Board (1302021;

Appendix A)

In this translator, the control and

monitoring functions and the front panel

operator interfaces are found on the

Control Board. Front panel operator

interfaces are brought to the control board

using a 26 position conductor ribbon cable

that plugs into J60. The control board

controls and monitors the Power Supply

and Power Amplifier module through a 16

position connector J61 and two 20 position

connectors J62 & J63.

4.5.2.1 Schematic Page 1

U1 is an 8 bit RISC microcontroller that is

in circuit programmed or programmed

using the serial programming port J4 on

the board. When the microcontroller, U1,

is held in reset, low on pin 20, by either

the programming port or the external

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-12

watchdog IC (U2), a FET Q1 inverts the

reset signal to a high that connects to

the control lines of U5, an analog switch.

The closed contacts of U5 connects the

serial programming lines from J4 to U1.

LED DS10 will be lit when programming

port J4 is used.

U2 is a watchdog IC used to hold the

microcontroller in reset, if the supply

voltage is less the 4.21 VDC; (1.25 VDC

< Pin 4 (IN) < Pin 2 (Vcc). The

watchdog momentarily resets the

microcontroller, if Pin 6 (ST) is not

clocked every second. A manual reset

switch S1 is provided but should not be

needed.

Diodes DS1 through DS8 are used for

display of auto test results. A test board

is used to execute self test routines.

When the test board is installed,

Auto_Test_1 is held low and

Auto_Test_2 is allowed to float at 5

VDC. This is the signal to start the auto

test routines.

U3 and U4 are used to selectively enable

various input and output ICs found on

pages 2 & 3 of the schematic.

U1 has two serial ports available. In this

application, one port is used to

communicate with transmitter system

components where U1 is the master of a

RS-485 serial bus. The other serial port

is used to provide serial data I/O where

U1 is not the master of the data port. A

dual RS-232 port driver IC and a RS-485

Port driver are also in the second serial

data I/O system. The serial ports are

wired such that serial data input can

come through one of the three serial

port channels. Data output is sent out

through each of the three serial port

channels.

Switch SW1, transmitter operation

select, is used to select either

transmitter operation or exciter/driver

operation. When the contacts of SW1

are closed, transmitter operation is

selected and the power monitoring lines

of the transmitter’s power amplifier are

routed to the system power monitoring

lines.

4.5.2.2 Schematic Page 2

U9 is a non-inverting transceiver IC that

provides 2 way asynchronous

communication between data busses. The

IC is used as an input buffer to allow the

microcontroller to monitor various digital

input values.

Digital output latch circuits are used to

control system devices. Remote output

circuits are implemented using open drain

FETs, Q13, Q14, Q16, and Q17, with

greater than 60 Volt drain to source

voltage ratings.

Remote digital inputs are diode protected,

using CR6, CR7, CR8 and CR9 with a 1 kO

pull-up resistor, to +5 VDC. If the remote

input voltage is greater than about 2 Volts

or floating, the FET is turned on and a

logic low is applied to the digital input

buffer, U9. If the remote input voltage is

less than the turn on threshold of the FET

(about 2 VDC), a logic high is applied to

the digital input buffer, U9.

Four of the circuits on page two of the

schematic, which include Q2, Q9, Q19 and

Q21, are auxiliary I/O connections wired

for future use. They are wired similar to

the remote digital inputs but include a

FET, Q5, Q12, Q20 and Q22, for digital

output operations. To operate these

signals as inputs, the associated output

FET must be turned off. The FETs are

controlled by U10 and U12, analog input

multiplexer ICs.

4.5.2.3 Schematic Page 3

U13, U14, U15, U16, U17 and U18 are 3

state non-inverting transceiver ICs that

provide 2 way asynchronous

communication between data busses. The

ICs are used as input buffers to allow the

microcontroller to monitor various digital

input values. The digital inputs to the ICs

utilize a 10 kO pull-up resistor. The buffer

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-13

IC, U18, used for data transfer to the

display is wired for read and write

control.

4.5.2.4 Schematic Page 4

U19 and U20 are digitally controlled

analog switches that provide samples

back to the microprocessor. Each

analog input is expected to be between

0 and 5 VDC. If a signal exceeds 5.1

VDC, a 5.1 Volt zener diode clamps the

signals voltage, to prevent damage to

the IC. Most signals are calibrated at

their source, however two dual serial

potentiometers ICs are used to calibrate

four signals, System Visual/Average

Power, System Aural Power, System

Reflected Power and the Spare AIN 1.

For these four circuits, the input value is

divided in half before it is applied to an

op-amp. The serial potentiometer is

used to adjust the output signal level to

between 80 and 120% of the input

signal level. Serial data, serial clock and

serial pot enables are supplied by the

microprocessor to the dual serial

potentiometer ICs. J62 and J63 are two

20 position connectors that provide the

+12 VDC and –12 VDC power through

the Power Protection Board. The ±12

VDC generated by the switching power

supply connects to J62 and J63 after

being fuse protected on the Power

Protection Board.

4.5.2.5 Schematic Page 5

There are three dual element,

red/green, common cathode LED

indicators mounted on the front panel of

the sled assembly; DC OK, Operate and

Fault.

There are three, the fourth is a spare,

identical circuits that drive the front

panel mounted LED indicators. The

levels on the 1, 2, 3 and 4 LED Control

Lines, for both the red and green LEDs,

are generated by the IC U11 as

controlled by the DATABUS from the

microprocessor U1.

Each LED controller circuit consists of an

N-Channel MOSFET w/internal diode that

controls the base of an N-P-N transistor in

an emitter follower configuration. The

emitter of the transistor connects the LED.

With the LED control line LOW, the

MOSFET is Off, which causes the base of

the transistor to increase towards +12

VDC, forward biasing the transistor. With

the transistor forward biased, current will

flow from ground through the LED, the

transistor and the current limiting

resistors in the collector to the +12 VDC

source. The effected LED will light.

With the LED control line HIGH, the

MOSFET is On, which causes the base of

the transistor go toward ground potential,

reverse biasing the transistor. With the

transistor reverse biased, no current

through the transistor and LED, therefore

the effected LED will not light.

A third color, amber, can also be

generated by having both transistors

conducting, both control lines LOW. The

amber color is produced because the

current applied to the green element is

slightly greater than the red element.

This occurs because the current limiting

resistors have a smaller ohmage value in

the green circuit.

There are four voltage regulators, three

for +5 VDC and one for +7 VDC, which

are used to power the Control Board. +12

VDC is applied to U25 the +7 VDC

regulator that produces the +7 VDC,

which is applied to the LEDs mounted on

the board. The +7V is also connected to

the input of U26 a precision +5.0 Volt

regulator. The +5.0 VDC regulator output

is used to power the analog circuits and as

the microcontroller analog reference

voltage. Another two +5 Volt regulator

circuits U27, +5V, and U8, +5 Vserial, are

used for most other board circuits.

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-14

4.5.3 (A4) Switch Board (1527-1406;

Appendix A)

The switch board provides five front-

panel momentary contact switches for

user control and interface with the front-

panel LCD menu selections. The

switches, SW1 to SW5, complete the

circuit through connector J1 to

connector J2 that connects to J1 on (A5)

the 20 Character by 4 line LCD Display.

J1 on the switch board is also cabled to

the Control Board. When a switch is

closed, it connects a logic low to the

control board that supplies the

information from the selected source to

the display. By pushing the button

again, a different source is selected.

This occurs for each push button. Refer

to Chapter 3, for more information on

the Display Menu Screens.

4.5.4 (A2) Switching Power Supply

Assembly

The power supply module contains a

switching power supply, an eight

position terminal block for distributing

the DC voltages, a three position

terminal block to which the AC Input

connects. Jack J1 connects to the

Control Board and supplies DC OK, at

J1-4 & 3, and AC OK, at J1-2 & 1, status

to the control board. A Power Supply

enable connects from the control board

to the power supply at V1-6 & 7. The

power supply is configured for three

output voltages +12V, -12V, at the 8

position terminal block, and a main

output power of +32 VDC at J50 pin A

(+) and J50 pin B (Rtn). The power

supply is power factor corrected to .98

for optimum efficiency and a decrease in

energy consumption. For safety

purposes all outputs are over voltage

and over current protected. This supply

accepts input voltages from 85 to 264

volts AC, but the power entry module,

for the exciter/amplifier chassis, must

be switched to the proper input voltage

setting, for the transmitter to operate.

4.7 (A6) Power Amplifier Assembly,

VHF High Band, (1305833; Appendix A)

The Power Amplifier Module Assembly

1305833 contains (A2) a 25 Watt VHF

Driver Pallet 1305820, (A4) a VHF HB

Coupler Board 1211-1004, and (A5) an

Amplifier Control Board 1308260.

4.7.1 (A2) 25 Watt VHF Driver Pallet

(1305820; Appendix A)

The RF input at a level of approximately +4

dBm connects to the RF input jack on the

(A2) Driver Assembly Pallet. The pallet is

an assembly manufactured by Delta RF

and has a gain of approximately +30dB.

The Refer to the Delta RF data sheet

(PA25-VHF-H) located in Appendix A for

more information on the assembly. The RF

output, approximately+34 dBm, connects

to the RF input jack on (A4) the coupler

board assembly.

The +30 VDC bias voltage connects from

the amplifier control board at TB18 to the

feed thru capacitor FL2 on the module

assembly that is wired to the +Vdd input on

the 25 Watt VHF Amplifier Assembly.

4.7.2 (A4) Coupler Board Assembly

(1211-1004; Appendix A)

The coupler board assembly provides

forward and reflected power samples of the

output to (A5) the amplifier control board

where they connect to the metering and

overdrive protection circuits in the system.

The RF input to the coupler assembly, from

the 25 Watt VHF Amplifier module,

connects to the SMA jack J1. In the

assembly, the RF is connected by a

stripline track to the SMA type connector

RF Output jack J2. A hybrid-coupler circuit

picks off a power sample that is connected

to a SMA type connector jack J3 as the

forward power sample. Another power

sample is taken from the coupler circuit

that is connected to the SMA type

connector jack J4 as the reflected power

sample.

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-15

4.7.3 (A5) Amplifier Control Board

(1308260; Appendix A)

The amplifier control board provides LED

fault and enable indications on the front

panel of the module and also performs

the following functions: overdrive

cutback, when the drive level reaches the

amount needed to attain 110% output

power; and overtemperature, VSWR, and

overdrive faults. The board provides

connections to the LCD Display for

monitoring the % Reflected Power, %

Output Power, and the power supply

voltage.

If the Module OK LED, located on the

front panel, is Red and blinking, a fault is

present. The meaning of the blinking

LED is as follows.

1 Blink: Indicates Amplifier Current

Fault.

2 Blinks: Indicate Temperature Fault.

3 Blinks: Indicate +32V Power Supply

Over Voltage Fault.

4 Blinks: Indicate +32V Power Supply

Under Voltage Fault.

5 Blinks: Indicate Reflected Power Fault.

6 Blinks: Indicate +12V or –12V Power

Supply Fault

If the Module OK LED, located on the

front panel, is Amber and blinking, it

indicates the power output of the

amplifier has dropped below 65%.

(NOTE: Only in Amplifier Code Versions

3.7A or later and System Controller Code

Versions 3.9C or later.).

4.7.3.1 Schematic Page 1

U4, located upper center of page, is an in

circuit microcontroller. The controller is

operated at the frequency of 3.6864 MHz

using crystal Y1. Programming of this

device is performed through the serial

programming port J2. U4 selects the

desired analog channel of U3 through the

settings of PA0-PA2. PA3 of U4 is a

processor operating LED that can be

flashed to show continued operation.

PF1 is used to monitor the +12VDC

supply to the board. PF4 is the selected

channel of analog switch U3. PF3 is

connected to a via, V10, for future access.

U2 is a serial to RS-485 driver IC. U5 is a

watchdog IC used to hold the

microprocessor in reset, if the supply

voltage is less than 4.21 VDC. U5

momentarily resets the microcontroller if

Pin 6 (!ST) is not clocked every second. A

manual reset switch is provided but should

not be needed.

In the Upper left corner, U1 is used to

determine where the amplifier control

board is located. The eight inputs come

from the main amp connector J8 and are

used to set the SCADA address of the

controller. Pull-up resistors set a default

condition of logic high.

U6 below U1 is used to control two of the

four board mounted status LEDs and three

other circuits that are not allowed to

change state during a microcontroller

reset. A FET is turned On to shunt current

away from the LED to turn it Off. U8 below

U6 is used to enable different features

within the software. Actual use is to be

determined.

4.7.3.2 Schematic Page 2

In the lower right corner are voltage

regulator circuits. U17 should allow for

0.14 amps of power using its 92 C/W

rating if Ta = 60°C max and Tj = 125°C

max. 0.26 amps can be obtained from

U17 if the mounting pad is 0.5 square

inches. The controller will not need this

much current. U18 and U19 are low drop

out +5 VDC, voltage regulators with a

tolerance greater than or equal to 1%.

100mA of current is available from each

device but again the controller will not

need this much current.

In the upper left section are circuits with

U9 and U11. U11 is used to generate a

regulated voltage that is about 10 volts

less than the +32 VDC supply,

approximately +20.75 VDC. When the

+32 VDC supply is enabled, the circuitry

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-16

around U9A is used to provide gate

voltage to Q14 that is 5 volts greater

than the source pin of this FET. The gate

of Q14 can be turned Off by any one of a

few different circuits.

U10A is used to turn Off the gate of Q14

in the event of high current in amplifier

#1. At 1.10 VDC the current to amplifier

#1 should be greater than 6.2 Amps.

U10B is used to turn off the Q14 FET, if

high current is detected in amplifier #2.

U12A is used to turn off the Q14 FET, if

high current is detected in amplifier #3.

With 2.743 VDC at Pin 5 of U10B or Pin 3

of U12A, the voltage output of current

sense amplifier U15 or U16, at high

current shut down, should be greater

than 15 Amps. These circuits are wired

through Q12 and Q13. At this time,

these transistors are not installed but

they may be installed to increase the

shut-down time on a detected fault.

Without Q12 and Q13 installed, Q14 is

only turned off by the microcontroller

through Q16.

U10A is used to detect high current in

amplifier #1. At 1.10 VDC, the current

to amplifier #1 should be 6.2 Amps.

U10B and U12A are used to detect high

current conditions in amplifier stages #2

and #3. With 2.74 VDC reference, high

current shut down should be

approximately 15 Amps.

U12B is used to turn Off the gate of Q14

in the event of high power supply

voltage, approximately +35.4 VDC.

U13A is used to keep the FET disabled in

the event of low power supply voltage,

approximately +26 VDC.

4.7.3.3 Current monitoring sections of

the board.

The ICs U14, U15 and U16 along with

associated components set up the

current monitoring sections of the board.

R67, R68 and R69 are 0.01O/5W 1%

through hole resistors used for

monitoring the current through several

sections of the amplifier. The voltage

developed across these resistors are

amplified for current monitoring by U14,

U15 or U16. The LT1787HVCS8 precision

high side current sense IC amplifier

accepts a maximum voltage of 60 VDC.

The 43.2 kO resistor from pin 5 to ground

sets the gain of the amplifier to about

17.28. This value is not set with much

accuracy since the manufacturer internally

matches the resistors of this part but their

actual resistance value is not closely

defined. A trimming resistor is suggested

to give a temperature stability of –200

ppm/C, but instead the microcontroller will

determine the exact gain of the circuit and

use a correction factor for measurements.

A6 is a temperature sensor thermistor

that is used to monitor the temperature of

the module's heat sink. It connects to J6

pins 1 & 2 on the board and is wired to

the comparator IC U13B. If the

temperature increases above 75°C the

output will go Low that is used as a

temperature fault output, which generates

a Fault alert and disables Amplifier #1.

4.7.3.4 Schematic Page 3, RF power

detector circuits.

Q16 is used by the microcontroller to

disable the aural circuit of a digital

transmitter or in external amplifiers where

the amplifier is not to monitor visual

power. A Forward Power Sample enters

the board at SMA Jack J3 and is connected

to pin 1 of U23. The output at Pin 6 of U23

is split with one input connected to J4 on

the board that is cabled to J1, the SMA

Forward Power Sample Jack, located on the

front panel of the assembly. The other

part of the split forward power sample is

detected by CR24 and the DC level

amplified by U21B. The output of U21B at

pin 7 is split with one part connected to

test point TP2, forward power sample. The

other split output connects to U21C that is

part of the Forward Average Power circuit.

The detected level is connected through

the average/visual calibration pot R202 to

U24A, a comparator IC that has Aural Null

and Offset Null, if present in the system,

connected to the other input. The output

LX Series VHF Translator Chapter 4,

Circuit Descriptions

LX Series, Rev. 0 4-17

Average Forward power level connects to

J9 pin 1 of the board.

A Reflected Power Sample enters the

board at SMA Jack J5 and is detected by

CR31 and the DC level amplified by

U21D. The output of U21D at pin 14 is

connected through the reflected

calibration pot R201 to U25A. The output

is split with one part connected to J9 pin

5, the Reflected Power Output level of

the board. The other part of the split

from U25A connects to the comparator

IC U25B that has a reference level

connected to the other input. If the

reflected level increases above the

reference level a low output is produced

and connected to the Reflected Power

Shutdown circuit at CR14 and CR5 on

Page 2 of the schematic. This produces a

Reflected Power Fault that is connected

to an output of the board, the Fault Alert

circuit and shuts down Amplifier #1.

Gain of the power measurements is

completed through software. Only the

Aural Null and Offset Null, if used, need

to be done through front panel pots.

NOTE: In this configuration the output of

U23 at pin 6 is not used. This circuit is

for analog 4.5 MHz and Aural power

samples.

This completes the description of the

1305833 20W Analog Power Amplifier

Module Assembly.

LX Series VHF Translator Chapter 5,

Detailed Alignment Procedures

LX Series, Rev. 0 5-1

Chapter 5

Detailed Alignment Procedures

This translator was aligned at the

factory and should not require additional

adjustments to achieve normal

operation.

The analog translator takes the VHF on

channel input, which connects to the

receiver module, that converts it to an IF

output which is then upconverted to the

desired UHF On Channel RF Output at

20W peak of sync visual power level.

The exciter/amplifier chassis assembly of

the LX Series translator is of a Modular

design and if a Module fails that module

can be easily changed out with a

replacement module. The failed module

can then be sent back to Axcera for

repair. Contact Axcera Customer Service

Department at 724-873-8100 or fax to

724-873-8105, before sending in any

module.

5.1 Module Replacement

Module replacement on the LX series

products is a relatively simple process.

All modules plug directly into the

backplane board except for the power

amplifier module that plugs into a blind

mating connector. To replace a module,

refer to the following procedure.

Loosen the two grip lock connectors,

located on the front panel, at the top

and bottom of the module,

counterclockwise until the module

releases. The Receiver, IF Processor,

Upconverter and Controller/Power

Supply can then be gently pulled from

the unit. To remove the Driver/Power

Amplifier Module in the exciter/amplifier

chassis assembly, the two cables, Input

and Output, connected to the rear of the

chassis must be removed. A 6/32” x ½”

shipping screw, located between the two

connectors, also must be removed

before the module will slide out. After

removal of the failed module, slide the

replacement module in place and make

certain it connects to the backplane

board. If the replacement module is a

driver/PA module replace the two cables

onto J24 and J25 on the rear of the

exciter/amplifier chassis assembly. The

6/32” x ½” shipping screw does not

need to be replaced. It is only used

during shipping. If the replacement

module does not slide in easily, verify it

is properly aligned in the nylon tracks,

located on both the top and bottom of

the module.

Note: Each Module has an assigned slot

and will not fit properly or operate in the

incorrect slot. Do not try to place a

Module in the wrong slot as this may

damage the slot or the connectors on

the backplane board. Each module has

the name of the module on the front,

bottom for identification and correct

placement. The Modules are placed in

the chassis assembly from left to right;

(1) Receiver, (2) Blank panel, (3) IF

Processor, (4) Upconverter, (5)

Controller/Power Supply and (6) Driver

Power Amplifier.

5.1.1 Initial Test Set Up

Check that the RF output of the

translator is terminated into a dummy

load of at least 20 Watts. While

performing the alignment, refer to the

Test Data Sheet for the system and

compare the final readings from the

factory with the readings on each of the

modules. The readings should be very

similar. If a reading is way off, the

problem is likely to be in that module.

Switch On the main AC for the system.

5.2 LX Series Exciter/Amplifier

Chassis Assembly

On the LCD Display, located on the

Controller/Power Supply Module, in the

Transmitter Set-Up menu, push the right

button to switch the translator to

Operate, STB will be displayed. The level

LX Series VHF Translator Chapter 5,

Detailed Alignment Procedures

LX Series, Rev. 0 5-2

of the RF output includes adjustments of

the drive level to the Power Amplifier and

the adjustment of the linearity and phase

predistortion to compensate for any

nonlinear response of the Power

Amplifier. The adjustments are located

on the front panel of the IF Processor

module.

5.2.1 Receiver Module Assembly

(Used in Analog Translator Only.)

Connect the on channel RF input to J12

the receiver RF input jack on the rear of

exciter/amplifier assembly. Verify that

all LEDs located on the front panel of the

Receiver are Green. The following details

the meaning of each LED:

PLL 1 Fault (DS6) - Displays the status

of the Local oscillator PLL

PLL 2 Fault (DS8) - Displays status of

optional input frequency correcting PLL

DC on center conductor (DS4) -

Displays whether or not DC is applied to

the RF input center conductor*

*Caution: Do not hook up the RF

input to any test equipment with the

DC bias applied. Always move the

jumper W1 on J2 on the VHF

Preamplifier board to the Bias off

position, between pins 2 & 3, before

beginning tests, to prevent possible

damage to the test equipment.

5.2.2 IF Processor Module Assembly

Verify that all red LEDs located on the IF

Processor front panel are extinguished.

The following details the meaning of each

LED when illuminated:

Input Fault (DS1) – Indicates that

either abnormally low or no IF is present

at the input of the IF Processor module.

• ALC Fault (DS2) – Indicates that the

ALC circuit is unable to maintain the

signal level requested by the ALC

reference. This is normally due to

excessive attenuation in the linearity

signal path or the IF phase corrector

signal path, or that switch SW1 is in

the Manual ALC Gain position.

• Mute (DS4) – Indicates that a Mute

command is present to the system.

Switch the translator to Standby. The

ALC is muted when the translator is in

Standby.

5.2.3 VHF/UHF Upconverter Module

Assembly

Switch the translator to Operate. Verify

that all LEDs located on the front panel of

the Upconverter are Green. The following

details the meaning of each LED:

PLL 1 Fault (DS1) - Displays the status

of the 1 GHz PLL, Green locked or Red

unlocked

PLL 2 Fault (DS2) - Displays status of

the 1.1-1.9 GHz PLL, Green locked or

Red unlocked

AGC Fault (DS7) - Displays status of

AGC, Green normal or Red out of range

AGC Override (DS3) - Displays status

of AGC cutback, either Green normal

drive level, no cutback, or too much

drive level to driver module, Red

cutback.

Manual Gain (DS6) - Displays status of

the control of the AGC level, either

Green normal, AGC Adj. using R6 or

Amber manual, Man Gain Adj. using R7.

The translator is now ready for normal

operation.

LX Series VHF Translator Chapter 5,

Detailed Alignment Procedures

LX Series, Rev. 0 5-3

5.3 Changing the Analog Translator

Output Channel Procedure

NOTE: Depending on the new channel

frequency, the bandpass filter may need

to be retuned or replaced to achieve

maximum output power.

Place the translator in Standby and go to

the Set Up Menu, Transmitter

Configuration Access Screen, on the LCD

Display by pushing the down arrow on

the default main screen and each

succeeding screen until the Transmitter

Set-Up Main Screen appears.

Transmitter Set-Up, Configuration

Access Screen

Enter the Set-Up screens by pushing the

ENT button. The following screen will

appear.

Authorized Personnel Screen

This screen of the translator notifies an

operator that they are only to proceed if

they are authorized to make changes to

the translator's operation. This screen is

implemented in transmitter software

version 1.4 and above. Push the ENT

button and step through the Set Up

screens by pushing the Down Arrow

button until the screen labeled

“Upconverter CH xx” is reached, as

shown in the following example. This

example shows the Transmitter set to

Channel 39.

Transmitter Set-up: Upconverter

Channel Select Screen

The choices of this screen are to the

standard UHF/VHF channels. The

channel number should be blinking. To

change the channel, hit the + button to

step through the channels until the

desired channel is reached.

To select a 10kHz offset to the channel

frequency, use the > button to move

the curser to the LO frequency listed

below the Channel number, and keep

pressing the > button until the desired

digit is blinking, and then use the +

button to change the frequency.

Example:

Nominal LO frequency for Channel 39 =

0667.00 MHz. To generate a + offset,

change the LO frequency to 0667.01

MHz. To generate a – offset, change the

LO frequency to 0666.99 MHz.

A safeguard is added to the Set Up

Menus in software version 2.5 and

above. If a change is made to a screen

within the Set Up Menu, as was just

completed with the channel change,

when you go to the next menu, by

pushing the Down or Up Arrow, a screen

appears that asks if you accept the

change or want to return to the previous

menu to reconsider the changes made.

See the Accept or Return to previous

Menu Screen. To accept the changes,

the two buttons located under ACCEPT

must be pushed simultaneously. To

return to the previous Menu to make

corrections, the two buttons located

under the RETURN must be pushed

simultaneously. Upon returning to the

previous Menu, the correct input must

be entered and the above procedure

repeated, this time accepting the

changes.

LX Series VHF Translator Chapter 5,

Detailed Alignment Procedures

LX Series, Rev. 0 5-4

Accept or Return to previous Menu

Screen

Pushing these two Pushing these

buttons together two buttons

will accept the together will return

change. you to the previous

Menu.

Accepting the changes will put you back

to the Main Set-Up Screen.

5.4 Adjusting the Manual AGC, Auto

AGC, and the Overdrive Cutback

Protection (AGC Cutback) in the

Analog Translator

NOTE: For alignment and calibration of

the digital translator proceed to the

Section 5.8.

NOTE: The translator was setup and

calibrated at the factory and should

require no adjustment to attain normal

operation.

5.4.1 Setting the Manual AGC

Switch the Translator to Standby. Preset

the front panel “Man Gain” pot on the

Upconverter full Counterclockwise,

and the Man/Auto Gain Switch to the

Left, Man.

Turn the translator to Operate, and

slowly adjust the “Man Gain” pot until

the desired % output power, as read on

the LCD display, has been reached.

The Manual AGC is now set. Normal

operation of the Translator is in the Auto

AGC position.

5.4.2 Setting the Auto AGC

With the translator in Standby, preset

the AGC pot on the Upconverter full

Counterclockwise. Preset the AGC

Cutback pot on the Upconverter full

Clockwise. Move the Man/Auto Gain

Switch on the Upconverter to the Right,

Auto. Switch the translator to Operate

and slowly adjust the AGC pot until the

desired output power has been reached.

Monitor the output of the translator with

a Spectrum Analyzer and turn the power

up 1 dB higher than desired using the

AGC pot. Enter the Translator Set-Up

menu on the LCD Control Panel and step

through the screens until the screen

labeled “Inner Loop Gain” is reached.

The inner loop is adjustable from 0-255.

Push the + button to increase the Inner

Loop Gain until the power on the

spectrum analyzer just begins to

decrease. Now push the – button to

decrease the inner loop gain by 10%.

(Example: If it begins to affect power at

setting 160, drop it back down to 160-

16=144 or if it affects power at 100,

drop it down by 10 to 90, etc….).

5.4.3 Setting the AGC Cutback

Slowly turn the AGC Cutback Pot

Counterclockwise until the AGC

Override light begins to flicker, and the

output power begins to drop. Turn the

pot Clockwise slightly, so the light just

goes out and the power stabilizes.

Adjust the AGC pot until the power level

returns to the desired % output power

level. The Auto AGC is now set. Normal

operation of the Translator is in the Auto

AGC position.

The translator is now ready for normal

operation.

5.5 Calibration of the Forward and

Reflected Output Power for the

Analog Translator

NOTE: Only perform the following

procedures if the output power

calibration is suspect.

LX Series VHF Translator Chapter 5,

Detailed Alignment Procedures

LX Series, Rev. 0 5-5

5.5.1 Calibration of Forward Output

Power

Switch the translator to Standby and

place the Upconverter into Manual Gain.

Preset R205, the aural null pot on the

Amp Control board, fully CCW. Adjust

R204, the null offset pot on the Amp

Control board, for 0% visual output.

Perform the following adjustments with

no aural present by removing the aural

IF carrier jumper on the back of the

chassis assembly. Connect an RF On

Channel frequency with a sync and black

test signal modulated onto it to the

Receiver RF input jack J12 on the rear of

the exciter/amplifier chassis. Switch the

translator to Operate.

Next, set up the translator for the

appropriate average output power level:

Example is for a 20 Watt Translator.

• Sync + black 0 IRE

setup/wattmeter=11.9 watts

• Sync + black 7.5 IRE

setup/wattmeter=10.9 watts

NOTE: The translator must have 40 IRE

units of sync.

Adjust R202, visual calibration, on the

Amp Control board for 100% on the front

panel LCD display in the % Visual Output

position. (Examples of the screens are

shown below).

With the spectrum analyzer set to zero

span mode, obtain a peak reference on

the screen. Reconnect the aural carrier

jumper on the rear of the chassis

assembly. Turn the power adjust pot on

the front panel until the original peak

reference level is attained. Adjust R203

for a 100% aural power reading. Switch

to the Visual Output Power position and

adjust R205 (aural null pot) for 100%

visual power.

5.5.2 Calibration of Reflected Power

To calibrate the reflected output power

reading of the translator. Reduce the

manual gain pot R3 to a 10% reading on

the LCD front panel display in the %

Output Power position. Place the

translator in Standby. Remove the PA

Module Sled. Remove the load from J4

on the (A4) Directional Coupler Board

and switch the LCD Display screen to the

Reflected Output Power position.

Reinstall the PA Module. Switch the

translator to operate. Adjust the

reflected power calibration adjust pot

R163 on the power amplifier module to a

10% reading. A reflected power fault

should be present on the LCD Display.

Reconnect the load to J4 in the module.

After this calibration is completed, move

switch SW1 on the upconverter module

to the Automatic AGC position. This is

the normal operating position for the

switch. Adjust the ALC pot on the IF

Processor as needed to attain 100%

output power. Switch to Manual Gain

(Manual AGC) and adjust the Manual

Gain pot for 100 % output power.

Switch the upconverter back to

Automatic AGC.

The translator is now ready for normal

operation.

LX Series VHF Translator Chapter 5,

Detailed Alignment Procedures

LX Series, Rev. 0 5-6

5.6 Linearity Correction Adjustment

for the Analog Translator

As shipped, the exciter was preset to

include amplitude and phase pre-

distortion. The pre-distortion was

adjusted to approximately compensate

the corresponding non-linear distortions

of the Power Amplifier.

NOTE: On the IF processor board inside

the IF Processor module, the correction

enable/disable jumper W12 on J30 must

be in the Enable position, on pins 2 & 3.

This is the normal operating position.

Set up a spectrum analyzer with

100 kHz resolution bandwidth and

100 kHz video bandwidth to monitor the

intermodulation products of the RF

output signal of the Power Amplifier.

A typical red field spectrum is shown in

Figure 5-1.

Figure 5-1: Typical Red Field Spectrum

in Analog Translator

There are three Linearity Corrector stage

adjustments located on the front panel

of the IF Processor Module. The

adjustments are threshold settings that

are set up as needed to correct for any

amplitude or phase intermod problems.

Adjust the top linearity correction

adjustment R211 threshold cut in for the

in phase amplitude distortion pre-

correction that is needed. Next, adjust

the middle linearity correction

adjustment R216 threshold cut in also

for the in phase amplitude distortion

pre-correction that is needed. Finally,

adjust the bottom linearity correction

adjustment R231 threshold cut in for the

quadrature phase distortion pre-

correction that is needed. The above

pots are adjusted for the greatest

separation between the peak visual

carrier and the intermod products.

NOTE: These pots affect many other

video parameters, so care should be

taken when adjusting the linearity

correction.

5.7 Frequency Response Delay

Equalization Adjustment for the

Analog Translator

NOTE: Perform the following procedure

only if a frequency response delay

equalization problem is suspect.

The procedure for performing a

frequency response delay equalization

adjustment for the translator is done at

IF and is described in the following steps:

The center frequency for the first stage is

42 MHz. Adjust R103, the top frequency

response equalizer pot, located on the

front panel of the IF Processor Module,

for the best depth of frequency response

correction at 42 MHz.

The center frequency for the second

stage is 43.5 MHz. Adjust R106, the

middle frequency response equalizer pot,

located on the front panel of the IF

Processor Module, for the best depth of

frequency response correction at 43.5

MHz.

The center frequency for the third stage

is 45 MHz. Adjust R274, the bottom

frequency response equalizer pot, located

on the front panel of the IF Processor

Module, for the best depth of frequency

response correction at 45 MHz.

After the three delay attenuation

equalizers have been adjusted, fine tune,

as needed, for the best frequency

response across the channel.

LX Series VHF Translator Chapter 5,

Detailed Alignment Procedures

LX Series, Rev. 0 5-7

The Analog Translator is now aligned,

calibrated, and ready for normal

operation.

If a problem occurred during the

alignment, help is available by calling

Axcera field support at (724) 873-8100.

APPENDIX A

SYSTEM AND EXCITER/AMPLIFIER

DRAWINGS

LX Series VHF Translator Appendix A, System

LX Series, Rev. 0 A-1

Innovator LX Series VHF Translator System

LX Series Analog Translator Block Diagram ............................................1309398

LX Series Analog Translator System Interconnect ...................................1309399

Chassis Assembly, 110 VAC Exciter, V2, LX Series

Interconnect.......................................................................................1304064

Backplane Board, V2, LX Series

Schematic..........................................................................................1304049

Receiver Assembly, VHF (Part of the Analog Translator System)

Interconnect.......................................................................................1304005

Block Diagram....................................................................................1304004

IF ALC Board

Schematic..........................................................................................1304011

VHF Preamplifier Board

Schematic..........................................................................................1306446

VHF Mixer/PLL Board

Schematic..........................................................................................1306473

IF Processor Assembly

IF Processor Board

Schematic..........................................................................................1301983

VHF/UHF Upconverter Assembly

Block Diagram....................................................................................1303830

Interconnect.......................................................................................1303831

Downconverter Board Assembly

Schematic..........................................................................................1303836

First Conversion Board, LX Series

Schematic..........................................................................................1303840

L-Band PLL Board, LX Series

Schematic..........................................................................................1303848

Upconverter Control Board, LX Series

Schematic..........................................................................................1304761

Control/Power Supply Assembly, 110 VAC

Block Diagram....................................................................................1303889

Interconnect.......................................................................................1302062

Control Board

Schematic..........................................................................................1302023

Power Protection Board

Schematic..........................................................................................1302839

Switch Board

LX Series VHF Translator Appendix A, System

LX Series, Rev. 0 A-2

Schematic.......................................................................................1527-3406

20W Analog Power Amplifier Assembly, Low Band

Block Diagram.........................................................................................1307159

Interconnect.......................................................................................1307158

VHF Coupler

Schematic.......................................................................................1153-3104

VHF Low Band Driver Board

Schematic.......................................................................................1153-3107

VHF Low Band Output Amplifier Board

Schematic.......................................................................................1172-3101

VHF Amplifier Control Board

Schematic..........................................................................................1308261

UBS Axcera LLV20AL 20-Watt VHF Low Band Translator User Manual TITLE PAGE

UBS-Axcera 20-Watt VHF Low Band Translator TITLE PAGE

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