Tait TBAL0 Base Station Transceiver User Manual TB8100 Calibration Kit User s Manual

Tait Limited Base Station Transceiver TB8100 Calibration Kit User s Manual

UserManual.wiki >

Tait >

TBAL0 User Manual HTML Version

Exhibit D Users Manual per 2 1033 c3

Calibration Kit

User’s Manual

MBA-00011-05

March 2005

TB8100 base station

TB8100 Calibration Kit User’s Manual Contents i

Contents

Preface ..............................................................................................................iii

Enquiries and Comments ..................................................................iii

Updates of Manual and Equipment ...................................................iii

Disclaimer ........................................................................................iii

Typographical Conventions ..............................................................iii

Associated Documentation ...............................................................iii

Publication Record ..........................................................................iv

Basic Tasks .........................................................................................................1

Using the TB8100 Calibration Kit ..........................................................1

About the Toolbar ............................................................................2

About the Status Bar ..........................................................................2

Equipment Required ..............................................................................3

Calibration Overview .............................................................................3

Field Calibration ................................................................................4

Service Center Calibration .................................................................4

Selecting the Communications Port ........................................................5

Connecting to a Reciter Outside the Subrack .........................................5

Connecting to a Reciter via the Control Panel .......................................7

Disconnecting from the Base Station/Reciter .........................................7

Troubleshooting .....................................................................................8

Adjusting the Frequency Setup ........................................................................9

Adjusting the Receiver Lock Band .........................................................9

Tuning the Receiver Front End ...........................................................10

Tuning a K-Band, H-Band, or L-Band Receiver Front End ............11

Tuning a VHF Receiver Front End .................................................12

Adjusting the Exciter Lock Band ..........................................................13

Calibrating the Reciter ....................................................................................14

Calibrating the Exciter ..........................................................................14

Automatically Tune the Frequency Control Loop (FCL) .................14

Calibrating the FCL .........................................................................14

Calibrating the VCO .......................................................................16

Calibrating the RSSI .............................................................................17

Audio Calibration .................................................................................18

Calibrating the Balanced Lines .........................................................18

Calibrating the Unbalanced Lines ....................................................19

Carrier Frequency Offset Adjustment

(Older Reciters) ....................................................................................21

Carrier Frequency Offset Adjustment

(Newer Reciters) ..................................................................................22

Calibrating the Power Amplifier ....................................................................24

ii Contents © Tait Electronics Limited 2005

Calibrating the PA Bias ........................................................................ 24

Calibrating the Forward and Reverse Detector Bias Voltages ............... 25

Calibrating the PA Power .................................................................... 25

Troubleshooting Tips ..................................................................... 26

Calibrating the Supply Voltage ............................................................. 27

Calibrating the Power Management Unit .................................................... 28

Calibrating the PMU Output Voltage .................................................. 28

Index .................................................................................. 29

TB8100 Calibration Kit User’s Manual Preface iii

Preface

Welcome to the TB8100 Calibration Kit User’s Manual. This manual provides

you with information about the Tait TB8100 Calibration Kit in PDF format.

You can view it online or print it if you want a paper copy. It describes how to

use Version 02.05 of the Calibration Kit.

Enquiries and Comments

Any enquiries regarding this manual as well as any comments, suggestions and

notifications of errors should be sent to support@taitworld.com, or addressed

to the Support Group Manager, Tait Electronics Limited, PO Box 1645

Christchurch, New Zealand.

Updates of Manual and Equipment

In the interests of improving the performance, reliability or servicing of the

equipment, Tait Electronics Limited reserves the right to update the equipment

or this manual or both without prior notice.

All information contained in this manual is the property of Tait Electronics

Limited. All rights are reserved. This manual may not, in whole or in part, be

copied, photocopied, reproduced, translated, stored, or reduced to any

electronic medium or machine-readable form, without prior written

permission from Tait Electronics Limited. All trade names referenced are the

service mark, trademark or registered trademark of the respective

manufacturers.

Disclaimer

There are no warranties extended or granted by this manual. Tait Electronics

Limited accepts no responsibility for damage arising from use of the information

contained in the manual or of the equipment and software it describes. It is the

responsibility of the user to ensure that use of such information, equipment and

software complies with the laws, rules and regulations of the applicable

jurisdictions.

Typographical Conventions

‘File > Exit’ means ‘click File on the menu bar, then select Exit’.

Associated Documentation

■Online Help. The Calibration Kit also has online Help. It contains more or

less the same information as this manual. To view it, start the Calibration

Kit, then press F1 or click the Help icon on the toolbar. If you are in a dialog

box, click the Help button.

■TB8100 Installation and Operation Manual.

■TB8100 Service Manual (service centers only). A glossary of terms is available

in this manual.

■TN-778 The TB8100 Calibration and Test Unit.

For additional items, see the TB8100 Installation and Operation Manual and

the TB8100 Service Kit User’s Manual or online Help.

iv Preface © Tait Electronics Limited 2005

Publication Record

Version Date Description

1.0 June 2003 First release of the manual for Version 1.0.0

of the Tait TB8100 Calibration Kit software.

02.00 March 2004 Minor quality issues resolved and software

changes documented for Version 02.00.

02.01

(MBA-00011-03)

September

2004

Carrier Frequency Offset Adjustment

procedure for reciter version 00.03+ added.

PA store supply voltage and PMU output

voltage calibration added.

02.02

(MBA-00011-04)

December

2004

Changes for K-band reciters.

02.05

(MBA-00011-05)

March

2005

Minor changes for Calibration Kit software

version 02.05. L-band reciters.

TB8100 Calibration Kit User’s Manual Using the TB8100 Calibration Kit 1

Basic Tasks

The TB8100 Calibration Kit is a Windows-based software program that allows

you to adjust the switching ranges of Tait TB8100 base stations (both receiver

and transmitter), and to flatten the receiver response across that switching range.

The TB8100 Calibration Kit is also used to calibrate the reciter, the PA, and

the PMU after servicing.

Using the TB8100 Calibration Kit

When you start the TB8100 Calibration Kit, the main program window

appears.

The main program window has four tabs. The Calibration Wizards displayed

on each tab are only visible once you are connected to the reciter or the base

station.

When the TB8100 Calibration Kit is connected to the reciter or base station,

you can view further details (such as module number, type, serial number, band,

and hardware version) about the currently selected module by clicking Show

Details.

Frequency Setup

tab Shows the three Calibration Wizards that take you step-by-step through the

frequency setup.

Reciter Calibration

tab Shows the seven calibration procedures that you can perform on the reciter.

The Calibration Wizard takes you step-by-step through the procedure you

have selected.

PA Calibration tab Shows the four calibration procedures that you can perform on the power

amplifier. The Calibration Wizard takes you step-by-step through the

procedure you have selected.

PMU Calibration

tab Shows the procedure that you can perform on the PMU.

Menu bar

Toolbar

Calibration

Wizards

Status bar

2 Using the TB8100 Calibration Kit © Tait Electronics Limited 2005

About the Toolbar

The toolbar gives you quick access to commonly used menu commands. For

example, instead of selecting Base Station > Calibrate, you can click the

Calibrate icon on the toolbar.

Connect Connects the TB8100 Calibration Kit to the base station and opens the

communication channels.

Switch Base

Station Lets you select another base station to calibrate if there are multiple base stations

in the rack (not currently supported).

Calibrate Runs the Calibration Wizard for the currently selected task.

Options Allows you to set the COM port and default calibration mode.

Help Opens the online help for the window you are currently in.

About the Status Bar

The status bar provides you with useful information that supplements the

display in the main window.

Miscellaneous messages COM port in use

TB8100 Calibration Kit User’s Manual Equipment Required 3

Equipment Required

You need the following equipment for field calibration:

■Calibration and test unit (CTU) (order code TBA0ST1) which comes with

the cables you will need for connection to the reciter/PA and the PC. For

more information about the CTU, please refer to TN-778 The TB8100

Calibration and Test Unit.

■Calibration test kit (order code TBA0ST2) which comprises tuning tools

and the required screwdrivers in a tool pouch

■10-30 V DC power supply

■RS-232 cable

■RF attenuator (optional – depends on the setup)

You may need the following additional equipment for a service center

calibration:

■Frequency counter

■Modulation meter

■RF signal source

■AC millivoltmeter (one with a differential input may be required for

“Calibrating the Balanced Lines” on page 18)

Refer to the individual procedures for equipment setup diagrams.

Calibration Overview

Any calibration process creates digital values and a calibration date, which are

stored in the base station. The Service Kit can display the date of the last

calibration. Many calibration procedures initially clear the stored digital values.

If you do not complete the procedure or the stored digital values are outside

acceptable limits, the module is left uncalibrated. An uncalibrated reciter will go

into Download mode on startup and cannot be put into Run mode. An

uncalibrated PA generates a calibration invalid alarm.

If the procedure you are performing requires access to tuning holes, you need

to remove the reciter from the subrack and connect to it via the CTU.

The following tables summarise, for each procedure, whether or not you need

to remove the reciter from the subrack, and what equipment (in addition to a

PC with the TB8100 Calibration Kit software) you will need.

25-way cable

15-way TaitNet

cable

16-way cable

Power cable

RF cable

BNC to BNC

cable

4 Calibration Overview © Tait Electronics Limited 2005

Field Calibration

The following procedures can be carried out in the field.

Service Center Calibration

The following additional procedures may need to be carried out after a module

has been serviced.

Note: Replacing or repairing a board module may mean that the

module’s product code, product type (frequency band), serial

number, and/or hardware version need to be re-entered or altered.

To do this, your Calibration Kit needs a dongle. The Service Manual indicates

when a module detail needs re-entering or altering.

Reciter

Procedure Connection Equipment Required

Adjusting receiver lock band Outside subrack Tuning tool, CTU

Tuning the receiver Outside subrack Tuning tool (with fine metal

tip for UHF reciter), CTU

Adjusting exciter lock band Outside subrack Tuning tool, CTU

Adjusting the carrier frequency

offset

Depends on

reciter

Tuning tool, Frequency

counter, RF attenuator (only

if using PA)

Procedure Connection Equipment Required

Automatically tuning FCL Inside subrack None

Calibrating the FCL modulation Outside subrack Tuning tool, CTU,

modulation meter, RF

attenuator (only if using PA)

Calibrating the VCO modulation Outside subrack Tuning tool, CTU,

modulation meter, RF

attenuator (only if using PA)

Calibrating the RSSI Inside subrack RF signal source

Calibrating the balanced lines Inside subrack CTU, AC millivoltmeter

(perhaps with differential

input)

Calibrating the unbalanced lines Inside subrack CTU, AC millivoltmeter

TB8100 Calibration Kit User’s Manual Selecting the Communications Port 5

Power Amplifier

Power

Management Unit

Selecting the Communications Port

Before you connect to a base station, you should first define the

communications (COM) port that you want to use.

To select the COM port

1. Select Tools > Options.

2. Select the port that you want to use from the COM Port list.

Note: The available COM ports are detected by the program and

appear in the list.

3. Click OK.

The COM port you selected is now shown on the status bar.

Connecting to a Reciter Outside the Subrack

Field calibration procedures require access to the tuning holes, so you need to

remove the reciter from the subrack and connect to it using a CTU.

Equipment ■Calibration and test unit (CTU)

■An IBM compatible PC

■10-30 V DC power supply

■16-way cable

■RS-232 cable

Procedure Connection Equipment Required

Calibrating the PA bias Inside subrack None required

Calibrating the forward &

reverse detector bias voltages

Inside subrack None required

Calibrating the PA power Inside subrack None required

Storing supply voltages Inside subrack Variable voltage external

power supply

Procedure Connection Equipment Required

Output voltage calibration Inside subrack Digital multimeter

6 Connecting to a Reciter Outside the Subrack © Tait Electronics Limited 2005

Setup

To connect to the reciter

1. Remove the reciter from the subrack (for instructions, see the Installation

and Operation Manual).

2. Set up the equipment as follows.

■Connect the reciter to the calibration and test unit (CTU) using the 16-

way cable.

■Connect your computer to the CTU by plugging the RS-232 cable into

the programming port.

■Using the power cable supplied in the calibration test kit, connect the

reciter to the 10-30 V DC power supply, but do not power it up yet.

3. Start the TB8100 Calibration Kit program, and check that the correct COM

port is selected.

4. Click Connect to start the connection process.

5. When you see the “Waiting for logon prompt from Reciter” screen, power

up the reciter. If it is already on, turn it off, and then on.

6. When the TB8100 Calibration Kit program has successfully connected to

the reciter, the Calibration Wizards are displayed in the main window.

You are now ready to tune and calibrate the reciter.

1PC 516-way cable

2RS-232 cable 6Reciter

3CTU 7Power cable

4Programming port 810-30 V DC power supply

TB8100 Calibration Kit User’s Manual Connecting to a Reciter via the Control Panel 7

Connecting to a Reciter via the Control Panel

For calibration procedures that do not require access to tuning holes, you can

leave the reciter in the subrack and connect your PC to the control panel as

follows.

Equipment ■An IBM compatible PC

■RS-232 cable

Setup

To connect to a reciter in the subrack

1. Connect your computer to the base station by plugging the RS-232 cable

into the serial port of the base station’s control panel.

Note: If the base station is fitted with a TaitNet RS232 system

interface, the control panel serial port is disabled; connect to the

serial port at the reciter rear instead.

2. Start the TB8100 Calibration Kit program, and check that the correct COM

port is selected.

3. Click Connect to start the connection process.

4. As soon as you see the “Waiting for logon prompt from Reciter” screen,

power up the base station. If it is already on, turn it off, and then on.

5. When the TB8100 Calibration Kit program has successfully connected to

the base station, the Calibration Wizards are displayed in the main window.

You are now ready to carry out calibration procedures.

Disconnecting from the Base Station/Reciter

Once calibration is completed, click Disconnect before exiting the Calibration

Kit.

Important: Disconnecting when a calibration process is not

completed may leave the base station in an uncalibrated state.

1Base station 3RS-232 cable

2Serial port 4PC

8 Troubleshooting © Tait Electronics Limited 2005

Troubleshooting

Application Errors All application errors are recorded in a log file called “CalError.log”. The data,

time, location, and any other useful information is stored in this file, which may

be helpful when troubleshooting.

The file is saved in the Logfiles subfolder of the application folder and stores up

to 1000 of the most recent logged items.

Verifying the

Software Version If you need to verify the version of the TB8100 Calibration Kit, select

Help > About.

Commands

Record All the commands sent and received by TB8100 Calibration Kit are saved in a

file called “CCTM.log”. The date, time, command number, and parameters are

all stored in this file, which may be helpful when troubleshooting.

The file is also saved in the Logfiles subfolder and stores up to 1000 of the most

recent logged items.

TB8100 Calibration Kit User’s Manual Adjusting the Receiver Lock Band 9

Adjusting the Frequency Setup

Before the TB8100 base station is installed, connected, and configured, you

must prepare it for operation by adjusting the switching range of the reciter, and

flattening the receiver response across the base station’s switching range.

Note: If the required switching range for the base station has already

been defined, you don’t need to perform these procedures.

To prepare the base station for operation

1. Adjust the receiver lock band

2. Tune the receiver front end

3. Adjust the exciter lock band

Tip: Use the TB8100 Service Kit to monitor the base station and

find out its current switching range.

Important: Be careful when using the tuning tool. Attempting to

turn the tool beyond the end of the range can crack the tuning slug.

Adjusting the Receiver Lock Band

The first step in preparing the TB8100 base station for operation is to adjust the

receiver lock band (switching range). The lock band is the range of frequencies

that the receiver is calibrated to operate on.

Equipment ■Tuning tool

■CTU

To adjust the receiver lock band

1. Remove the reciter from the subrack. (For instructions, see the Installation

and Operation Manual.)

2. Connect the Calibration Kit to the reciter (see “Connecting to a Reciter

Outside the Subrack” on page 5).

3. Select the Frequency Setup tab, and double-click Set Receiver VCO. The

Set Receiver VCO Wizard appears. The display varies, depending on the

reciter band.

4. Enter the Center Frequency (which must be a multiple of 500 kHz) of the

lock band that you want to use, and click Next.

5. Insert the tuning tool into the correct receiver VCO tuning hole for the

reciter type and then click Next.

UHF receiver VCO

tuning hole

VHF receiver VCO

tuning hole

10 Tuning the Receiver Front End © Tait Electronics Limited 2005

6. Adjust the receiver VCO trimmer until the actual band matches the desired

band. The bands turn green. Click Finish. This stores the lock band in the

reciter. The icon on the Frequency Setup tab indicates that this task is

complete. Proceed to tune the front end.

Tuning the Receiver Front End

The second step in tuning the reciter frequency is to tune the receiver front

end. Tuning aims to maximise the receiver’s sensitivity and to flatten its

response across the lock band (switching range).

To help you do this, there is a graph of the RSSI readings in step two of the

Tune Receiver Front End Wizard. A number of RSSI readings are measured

across the switching range. These readings are then continually averaged to

produce the graph.

You should aim to achieve a response that looks something like this:

On UHF, 800 MHz, and 900 MHz reciters, you adjust helical filters. On VHF

reciters, you adjust trimmer capacitors.

Equipment ■Tuning tool

■CTU

Setup

1PC 2RS-232 cable 3Programming port

4CTU 5Noise source 6Reciter

TB8100 Calibration Kit User’s Manual Tuning the Receiver Front End 11

Tuning a K-Band, H-Band, or L-Band Receiver Front End

To tune the receiver front end, follow these steps.

1. Ensure you are already connected to the reciter (see “Connecting to a

Reciter Outside the Subrack” on page 5).

2. Select the Frequency Setup tab, and double-click Tune Receiver Front

End. The Tune Receiver Front End Wizard appears.

3. Connect the CTU’s noise source to the receiver input, turn the noise source

on, and then click Next.

4. Click Coarse (fast) and use the tuning tool to roughly adjust the front-end

helical filters on the receiver. As you do so, observe the graphical RSSI

readings across the lock band. Adjust first for maximum RSSI, and then for

flatness.

Note: As the response gets flatter, you may find it helpful to select a

more sensitive scale, so that you can see the graphical reading in

more detail.

Use the tuning tool as follows.

a. Insert the tuning tool into the first hole of the first set. You can start with

the hole on the left side and proceed along to the hole on the right, or

vice versa.

b. Tune each of the resonators in the first set once to give the best response.

c. Insert the tuning tool into the first hole of the second set. You can start

with the top hole and proceed down to the bottom hole, or vice versa.

d. Tune each of the resonators in the second set once to give the best

response.

e. Repeat this procedure as necessary to refine the response.

5. Once you have roughly tuned the front-end helical filters, click Fine

(slow). Repeat the above procedure to fine tune the front-end helical filters

until the response is flat in the middle of the lock band and not more than

-1 dB at the ends of the band.

Note: When using the Fine (slow) setting, you may notice a slight

delay as the reading from tuning the front-end helical filters takes

approximately one second to appear on the graph.

First set

Second set

UHF helical

filters:

12 Tuning the Receiver Front End © Tait Electronics Limited 2005

6. Click Finish. The icon on the Frequency Setup tab indicates that this

task is complete.

Tuning a VHF Receiver Front End

To tune the receiver front end, follow these steps.

1. Ensure you are already connected to the reciter (see “Connecting to a

Reciter Outside the Subrack” on page 5).

2. Select the Frequency Setup tab, and double-click Tune Receiver Front

End. The Tune Receiver Front End Wizard appears.

3. Connect the CTU’s noise source to the receiver input, turn the noise source

on, and then click Next.

4. Click Coarse (fast) and use the tuning tool to roughly adjust the four

front-end trimmers on the receiver. You can do this in any order. As you

do so, observe the graphical RSSI readings across the lock band. Adjust first

for maximum RSSI, and then for flatness.

Note: As the response gets flatter, you may find it helpful to select a

more sensitive scale, so that you can see the graphical reading in

more detail.

5. Once you have roughly tuned the trimmers, click Fine (slow). Repeat the

above procedure until the response is flat in the middle of the lock band and

not more than -1 dB at the ends of the band.

Note: When using the Fine (slow) setting, you may notice a slight

delay as the reading from tuning the trimmers takes approximately

one second to appear on the graph.

6. Click Finish. The icon on the Frequency Setup tab indicates that this

task is complete.

VHF

trimmer holes

TB8100 Calibration Kit User’s Manual Adjusting the Exciter Lock Band 13

Adjusting the Exciter Lock Band

If you are preparing the base station for operation, adjusting the exciter lock

band is the third step in tuning the reciter. Alternatively, this procedure can be

performed independently of the other two calibration wizards on the

Frequency Setup tab. Adjusting the exciter lock band defines the range of

frequencies that the base station is able to transmit on. For K-band UHF

exciters, the procedure is somewhat different: you select one of the two lock

bands instead of defining a center frequency.

Note: When performing this procedure, you don’t need to

terminate the exciter output port. An internal output pad means that

there is a good impedance match at this interface.

Equipment ■Tuning tool

■CTU

To calibrate the exciter lock band

1. Ensure you are already connected to the reciter (see “Connecting to a

Reciter Outside the Subrack” on page 5).

2. Select the Frequency Setup tab, and double-click Set Exciter VCO. The

Set Exciter VCO Wizard appears.

3. Enter the center frequency (which must be a multiple of 500 kHz) of the

lock band that you want to use, and click Next.

Alternatively, for a K-band UHF exciter, select one of the two available lock

bands. This specifies the lock band that you adjust and that the exciter oper-

ates in.

4. Insert the tuning tool into the correct exciter VCO tuning hole (see below)

and adjust the trimmer until the actual band matches the desired band. The

bands turn green. (For K-band UHF exciters, adjustment should only be

necessary if the board has been repaired.) Click Finish.

Once you have finished adjusting the exciter lock band, the icon on the

Frequency Setup tab indicates that this task is complete.

Exciter VCO tuning hole

for H-band

Exciter VCO tunin

hole for VHF

Exciter VCO tuning

hole for K-band

(850-870 MHz) and

L-band (852-854 MHz)

Exciter VCO tuning

hole for K-band

(762-776 MHz) and

L-band (928-941 MHz)

14 Calibrating the Exciter © Tait Electronics Limited 2005

Calibrating the Reciter

The reciter is fully calibrated in the factory, but if the reciter is serviced you may

need to perform the following procedures:

■Calibrating the Exciter

■Calibrating the RSSI

■Audio Calibration

To compensate for frequency drift, you may need to perform the following:

■Carrier Frequency Offset Adjustment (Older Reciters) or

■Carrier Frequency Offset Adjustment (Newer Reciters)

All these procedures can be done independently of each other, although it is

recommended that you tune the receiver before you calibrate the RSSI.

Important: It is recommended that only accredited service centers

and Tait engineers perform these procedures.

Calibrating the Exciter

You will need to calibrate the exciter if you have made component-level repairs

to it. There are three procedures that must all be completed in order:

1. Auto-tune the FCL

2. Calibrate the FCL

3. Calibrate the VCO

Automatically Tune the Frequency Control Loop (FCL)

Tuning the FCL calibrates the voltage levels used in the detectors for the FCL.

To automatically tune the FCL

1. Connect the Calibration Kit PC to the reciter and start the Calibration Kit.

2. Select the Reciter Calibration tab, and double-click FCL Auto Tuning.

The FCL Auto Tuning Wizard appears.

3. Click Calibrate to automatically tune the FCL.

The icon on the Reciter Calibration tab indicates that this task is complete.

You will now need to calibrate the FCL.

Calibrating the FCL

This is step two of calibrating the exciter. Once you have auto-tuned the FCL,

you should calibrate it.

Equipment ■Tuning tool

■CTU

■Modulation meter

■RF attenuator (only required if you are using a PA)

TB8100 Calibration Kit User’s Manual Calibrating the Exciter 15

Setup

To calibrate the FCL

1. Ensure that the Calibration Kit PC is connected to the reciter.

2. Select the Reciter Calibration tab, and double-click FCL Calibration. The

FCL Calibration Wizard appears.

3. Attach an appropriate Load and Modulation meter to the PA or exciter

output, set the meter to measure the RMS deviation, and then click Next.

(If you are using a PA, it will now transmit.)

4. Insert the tuning tool into the correct exciter VCO tuning hole (see below)

and adjust the trimmer until the actual band matches the desired band. The

bands turn green. Click Next.

5. Use the slider to adjust the deviation at 1 kHz until it is 2107 Hz RMS

(3 kHz peak).

6. Select the 30 Hz Modulation Test and adjust the deviation at 30 Hz until it

is 2107 Hz RMS (3 kHz peak).

7. Repeat steps 5 and 6 until the deviation is 2107 Hz RMS at both 1 kHz and

30 Hz.

8. Click Finish. (If you are using a PA, it will now stop transmitting.)

When you have finished calibrating the FCL, the icon on the Reciter

Calibration tab indicates that this task is complete.

You will now need to calibrate the VCO.

1Reciter 3RF attenuator (only required if using a PA)

2PA (optional) 4Modulation meter

Exciter VCO tuning hole

for H-band

Exciter VCO tunin

hole for VHF

Exciter VCO tuning

hole for K-band (850-

870 MHz) and

L-band (852-854 MHz)

Exciter VCO tuning

hole for K-band (762-

776 MHz) and

L-band (928-941 MHz)

16 Calibrating the Exciter © Tait Electronics Limited 2005

Calibrating the VCO

This is step three of calibrating the exciter.

Once you have tuned and calibrated the FCL, you calibrate the VCO at

frequencies across the whole lock band. This involves selecting a sub-band,

adjusting the lock band trimmer, and then moving on-screen sliders to adjust

the deviation to 3 kHz for each of a set of frequencies.

Equipment ■Tuning tool

■CTU

■Modulation meter

■RF attenuator (only required if you are using a PA)

Setup

To calibrate the VCO

1. Ensure that the Calibration Kit PC is connected to the reciter.

2. Select the Reciter Calibration tab, and double-click VCO Calibration.

The VCO Calibration Wizard appears.

3. Attach an appropriate Load and Modulation meter to the PA or exciter

output, set the meter to measure the peak deviation, and then click Next.

(If you are using a PA, it will now transmit.)

4. Adjust the exciter lock band trimmer until the actual band matches the

desired band. The bands turn green.

5. Click Next. Step 3 of the wizard appears.

6. Calibrate each of the frequencies shown. Follow these steps.

a. Click the option button alongside a frequency.

b. Using the Fine and Coarse arrows, adjust the slider until the deviation

shown on the modulation meter is 3000 Hz (peak).

c. Repeat steps a) and b) until all frequencies for the band are calibrated.

This enables the Next Band button.

7. Click Next Band and repeat steps 4) through 6). Repeat until all

frequencies in all bands have been calibrated.

8. If you are connected to a K-band reciter, click Next. Select which of the

two available bands the reciter will operate on.

9. Click Finish. (If you are using a PA, it will now stop transmitting.)

When you have finished calibrating the VCO, the icon on the Reciter

Calibration tab indicates that this task is complete.

1Reciter 3RF attenuator (only required if using a PA)

2PA (optional) 4Modulation meter

1 2

TB8100 Calibration Kit User’s Manual Calibrating the RSSI 17

You should now adjust the exciter lock band because it was re-tuned several

times during this procedure. This means that the exciter is no longer on the

required frequency.

Calibrating the RSSI

Calibrating the RSSI (received signal strength indicator) ensures that the

reciter's internal RSSI values accurately reflect the actual received signal

strength. Changing the receiver's lock band can alter the calibration accuracy by

about 1 dB.

Note: Ensure that the receiver’s lock band has already been adjusted

to the required setting before carrying out this procedure. (See

“Adjusting the Receiver Lock Band” on page 9.)

Equipment ■RF signal source

Setup

To calibrate the RSSI

1. Ensure that the Calibration Kit PC is connected to the reciter.

2. Select the Reciter Calibration tab, and double-click RSSI Calibration.

The RSSI Calibration Wizard appears.

3. Apply a signal (modulated at 1 kHz tone, 3kHz deviation peak) at the base

station’s center frequency. Use the CTU to confirm that the tone is being

output on the line, and then click Next.

4. Set the RF input signal to a level of -80 dBm, and then click Next.

5. Vary the RF level, and check that the value shown in the RSSI Gain Setting

box corresponds with the value shown on your test instrument. This is to

make sure the RSSI is correctly calibrated. Click Finish.

When you have finished calibrating the RSSI, the icon on the Reciter

Calibration tab indicates that this task is complete.

1RF signal source

2Reciter

18 Audio Calibration © Tait Electronics Limited 2005

Audio Calibration

You should calibrate the audio outputs/inputs if the system interface has been

replaced or changed at all.

Note: The balanced and unbalanced lines can be calibrated

independently of each other.

Calibrating the Balanced Lines

Calibrating the balanced lines adjusts their gain, so that when you set line levels

using the TB8100 Service Kit software, the actual line level correctly reflects

the Service Kit settings. (Refer to the TB8100 Service Kit User’s Manual for

further information.)

Equipment ■CTU

■AC millivoltmeter

Important: If the reciter you are calibrating has either the product

code TBA4xxx-0A0x or TBA5xxx-0A0x, its balanced line output

is not transformer isolated. Ensure that the line meter you are using

has a differential input otherwise the balanced line output will not

be calibrated properly.

Setup for

Balanced Line Out

Setup for

Balanced Line In

1Reciter 3CTU 5Line output

225-way cable 4System interface port 6AC millivoltmeter

1Reciter 3CTU 5Line output

225-way cable 4System interface port 6AC millivoltmeter

7Line input

TB8100 Calibration Kit User’s Manual Audio Calibration 19

To calibrate the balanced input and output lines

1. Ensure that the Calibration Kit PC is connected to the reciter.

2. Select the Reciter Calibration tab, and double-click Balanced Line

Calibration. The Balanced Line Calibration Wizard appears.

3. Attach an AC millivoltmeter and terminate the balanced output in 600

ohms (either using the load on the CTU or looping the balanced output to

the balanced input), and then click Next.

4. Adjust the slider in the dialog box until the audio level on the millivoltmeter

reads 1 VPP (0.354 VRMS).

Note: Click Coarse to roughly adjust the audio level, and once you

get within range, click Fine for more precise control over the

settings. To move up or down 10 mVPP, click either side of the

slider bar.

5. Click Next. The balanced output is now calibrated.

6. Note the level of the AC millivoltmeter, and then turn off the 600 ohm

load.

7. Connect the balanced output to the balanced input. Verify that the

millivoltmeter reading is substantially unchanged. (This confirms that the

input provides a 600 ohm impedance.)

8. Click Finish. The balanced input is now calibrated.

When you have finished calibrating the balanced lines, the icon on the

Reciter Calibration tab indicates that this task is complete.

Calibrating the Unbalanced Lines

Calibrating the unbalanced lines adjusts their gain, so that when you set line

levels using the TB8100 Service Kit software, the actual line level correctly

reflects the Service Kit settings. (Refer to the TB8100 Service Kit User’s Manual

for further information.)

Equipment ■CTU

■AC millivoltmeter

Setup for

Unbalanced Line

Out

1Reciter 3CTU 5Unbalanced line output

225-way cable 4System interface port 6AC millivoltmeter

20 Audio Calibration © Tait Electronics Limited 2005

Setup for

Unbalanced Line

To calibrate the unbalanced input and output lines

1. Ensure that the Calibration Kit PC is connected to the reciter.

2. Select the Reciter Calibration tab, and double-click Unbalanced Line

Calibration. The Unbalanced Line Calibration Wizard appears.

3. Attach an AC millivoltmeter to the unbalanced line output, and then click

Next.

4. Adjust the slider in the dialog box until the audio level on the millivoltmeter

reads 1 VPP (0.354 VRMS) to calibrate the unbalanced line output, and then

click Next.

Note: Click Coarse to roughly adjust the audio level, and once you

get within range, click Fine for more precise control over the

settings. To move up or down 10 mVPP, click either side of the

slider bar.

The unbalanced line output is now calibrated.

5. Connect the unbalanced output to the unbalanced input, and then click

Finish.

The unbalanced line input is now calibrated.

When you have finished calibrating the unbalanced lines, the icon on the

Reciter Calibration tab indicates that this task is complete.

1Reciter 3CTU 5Unbalanced line input

225-way cable 4System interface port 6Unbalanced line output

TB8100 Calibration Kit User’s Manual Carrier Frequency Offset Adjustment (Older Reciters) 21

Carrier Frequency Offset Adjustment

(Older Reciters)

The carrier frequency is derived from a reference frequency generated by the

reciter’s TCXO (temperature compensated crystal oscillator). The reference

frequency can drift over time, causing an offset to the carrier frequency. When

you connect to a reciter with hardware version 00.02 or earlier, the Calibration

Kit provides the following procedure that enables you to adjust the carrier

frequency and remove the offset.

Reciters are delivered from the factory with a 0 offset. Carry out the following

procedure if you suspect that the base station is transmitting off-frequency.

(Off-frequency is defined as being outside the range of -1 to +1 ppm.) It is a

good idea to calibrate the TCXO every few years. Exactly how often you do

this will depend on the harshness of the conditions in which the base station is

operating.

Ideally, you should calibrate the TCXO at a room temperature of 25 +/- 5

degrees Celsius. Complete the calibration as quickly as possible since extended

transmission times increase temperature, which makes the calibration less

accurate.

Equipment ■Frequency counter

■RF attenuator (only required if you are using a PA)

Important: The accuracy of the calibrated TCXO frequency is only

as good as the accuracy of the frequency counter.

Setup

To adjust the carrier frequency

1. Ensure that the Calibration Kit PC is connected to the reciter (see

“Connecting to a Reciter via the Control Panel” on page 7).

2. Select the Reciter Calibration tab, and double-click Carrier Freq Offset

Adjustment. The Carrier Freq Offset Adjustment Wizard appears.

3. Attach an appropriate load and frequency counter (or a test set) to the exciter

or PA output, and then click Next. (This instructs the setup to transmit.)

4. Using the slider, adjust the TCXO pot until the actual frequency is exactly

the same as the selected frequency value. Click Coarse to roughly (and

quickly) adjust the output frequency, and then click Fine to fine-tune it.

When you have finished, click Finish. (The setup now stops transmitting.)

When you have finished, the icon on the Reciter Calibration tab indicates

that this task is complete.

1Reciter 3RF Attenuator pad (optional)

2PA (optional) 4Frequency counter

Carrier Frequency Offset Adjustment

(Newer Reciters)

The TCXO (temperature compensated crystal oscillator) provides a reference

frequency from which all other RF frequencies are derived. Reciters with

hardware version 00.03 and above have a voltage-controlled TCXO, with a pot

for adjusting the reference frequency to remove any carrier frequency offset.

The Carrier Freq Offset Adjustment wizard provides assistance with this

procedure.

Tait recommends that the reciter TCXO is recalibrated after 3 months service

and that annual checks are made thereafter in order to compensate for

frequency drift. Recalibration ensures that the SDB (signal displacement

bandwidth) is within 250 Hz.

The TCXO has a frequency stability of 0.5ppm (parts per million)

corresponding to 250Hz at a carrier frequency of 500MHz. Tait recommends

that the TCXO is calibrated to within 0.1ppm.

Equipment ■Torx 10 screwdriver (to remove the reciter cover)

■Tuning tool

■Frequency counter

■RF attenuator (only required if you are using a PA)

Important: The accuracy of the calibrated TCXO frequency is only

as good as the accuracy of the frequency counter.

Setup

You need direct access to the TCXO circuitry on the reciter RF board. This

involves removing the reciter RF cover.

Important: The reciter contains devices that are susceptible to

damage from static charges. You must handle these devices

according to the recommended ESD precautions.

To adjust the carrier frequency

1. Remove the reciter from the subrack.

2. Remove the M3 Torx screws securing the reciter RF cover to the heatsink

and to the front and rear panels. (The RF side of the reciter can be identified

by the two BNC connectors on that side of the reciter’s rear.) Lift off the

RF cover.

3. Connect the Calibration Kit to the reciter (see “Connecting to a Reciter

Outside the Subrack” on page 5).

4. Select the Reciter Calibration tab, and double-click Carrier Freq Offset

Adjustment. The Carrier Freq Offset Adjustment wizard appears.

1Reciter 3RF Attenuator pad (optional)

2PA (optional) 4Frequency counter

TB8100 Calibration Kit User’s Manual Carrier Frequency Offset Adjustment (Newer Reciters) 23

5. Attach an appropriate load and frequency counter (or a test set) to the exciter

or PA output, and then click Next.

The exciter now begins transmitting on the center frequency of its lock

band. The Wizard displays a message similar to the following:

“Adjust RV1400 to set frequency within 0.1ppm or 48Hz of 485MHz”

6. Use the tuning tool to adjust the TCXO tuning control (RV1400) so that

the reciter is transmitting exactly on frequency.

7. Click Finish. Transmission ceases and the icon on the Reciter

Calibration tab indicates that this task is complete.

8. Replace the reciter RF cover, as follows.

a. Slide the cover into place over the front and rear panels. Make sure the

holes in the cover line up with the threaded holes in the heatsink and

front and rear panels.

b. Press the cover firmly into place and screw in the M3 Torx screws, first

on the flat face, then on the edge face.

Calibrating the Power Amplifier

The PA is fully calibrated in the factory, but if the PA is serviced you may need

to perform the following procedures:

■Calibrating the PA Bias

■Calibrating the Forward and Reverse Detector Bias Voltages

■Calibrating the PA Power

■Calibrating the Supply Voltage

Perform the procedures in the above order.

Important: It is recommended that only accredited service centers

and Tait engineers perform these procedures.

Calibrating the PA Bias

The driver and final transistors of the power amplifier must be biased at a

constant current. Since the characteristics of individual transistors vary slightly,

the bias current is calibrated for each device.

If either the driver or final transistor, or the PCB modules themselves, are

replaced during servicing, you should perform this procedure to calibrate the

bias current for the new device.

The bias current required for each amplifier stage is stored within the PA.

During the calibration process, the microprocessor adjusts the gate bias voltage

to obtain the required bias current for each stage.

The stage bias calibration sets up the amplifier’s DC operating conditions.

These DC conditions will be upset if there is RF present during calibration. It

is important to disconnect the RF cable from the PA input to avoid this.

The other conditions which must be met to ensure a successful calibration are

as follows:

■No other Calibration Wizards are running

■The supply voltage is within the range 27-29V

■The temperature of each stage is within the range 5-50°C

To calibrate the PA stage bias current

1. Ensure that the Calibration Kit PC is connected to the base station.

2. Select the PA Calibration tab, and double-click Calibrate PA Bias.

3. Ensure that the exciter RF is isolated from the PA by disconnecting the

SMA connector on the PA front panel.

4. Click Calibrate to calibrate the PA bias.

When you have finished calibrating the power amplifier bias, the icon on

the PA Calibration tab indicates that this task is complete.

TB8100 Calibration Kit User’s Manual Calibrating the Forward and Reverse Detector Bias Voltages 25

Calibrating the Forward and Reverse Detector Bias Voltages

The RF detectors, used for measuring the forward and reverse power, operate

with a small bias current. The resulting bias voltage from each detector (with

no RF present) is read and stored inside the PA. These voltages are used when

calculating the Antenna VSWR (Voltage Standing Wave Ratio).

You should calibrate the forward and reverse detector bias voltages:

■If the Low Pass Filter (LPF)/directional coupler PCB module is replaced

■After servicing of any components in the detector circuitry (such as the

detector diodes) on the LPF/ directional coupler PCB

To calibrate the forward and reverse detector bias voltages

1. Ensure that the Calibration Kit PC is connected to the base station.

2. Select the PA Calibration tab, and double-click Calibrate Fwd/Rev

Detector Bias Voltages.

3. Ensure that the PA is not transmitting and that there is no RF source present

at the PA RF input or output by disconnecting the input SMA connector

on the PA front panel and the ‘N’ type output connector from the rear of

the PA. Click Calibrate.

When you have finished, the icon on the PA Calibration tab indicates that

this task is complete.

Calibrating the PA Power

The power amplifier (PA) receives the RF signal from the reciter and amplifies

it to the required level, in watts, as requested by the reciter. The desired output

power is determined by the reference voltage for the power control loop.

The PA power control loop is calibrated at a single frequency, generally in the

center of the operating band.

You perform the calibration procedure to define – for each power level – the

reference DAC (Digital-to-Analogue Converter) value and forward detector

voltage.

You should only need to re-calibrate the PA power if:

■The Low Pass Filter (LPF)/directional coupler PCB module is replaced

■Any repairs are carried out on the forward and reverse detector circuitry on

the Low Pass Filter/directional coupler PCB module

■You require a more accurate power calibration on a specific frequency

Equipment

■Either an inline power meter and 50 ohm load with a high power rating, or

■A terminating power meter and appropriate 50 ohm attenuator with a high

power rating

Setup for Inline

Power Meter

Note: Cables and connectors can easily cause a power loss of several

watts if either too long or poorly terminated. Always use the

shortest possible leads (or connectors instead of leads) between the

PA and power meter set-up.

To calibrate the PA transmit power

1. Ensure that the Calibration Kit PC is connected to the base station.

2. Select the PA Calibration tab, and select Calibrate PA Power.

3. Ensure that the power meter and a 50 ohm load (VSWR < 1.2:1) with a

high power rating are connected to the power amplifier RF output, and

then click Next.

4. Check that the PA RF input is connected to the reciter RF output, and that

the PA and the reciter are connected by a control bus, and then click Next.

5. For each power level shown, use the slider to adjust the DAC setting to get

the required power output, and then click Next Power to move to the next

line.

Note: Click Coarse to roughly adjust the DAC setting, and once

you get within range, click Fine for more precise control over the

settings. To move up or down one DAC value, click either side of

the slider bar.

Note: You must perform the calibration in sequence from the lowest

to the highest step. The DAC setting must be greater than the

previous one otherwise the value will not be stored in the PA, and

you cannot move to the next line.

6. When you have completed adjusting the DAC settings, click Finish.

When you have finished, the icon on the PA Calibration tab indicates that

this task is complete.

Troubleshooting Tips

DAC Settings When you adjust the DAC settings, the values for the DAC Setting, Coupler

Fwd Voltage, and Control Voltage should always increase as the power level

increases. If these values do not increase, there is either a fault with the PA or

the previous step was not calibrated correctly. If you make a mistake in the

calibration table, you must start again from step 1.

Control Voltage The Control Voltage is shown in the table to indicate the operation point

within the power control loop. The range of the control voltage is from 0 V to

7.5 V. If the control voltage reaches its limit before achieving maximum power

in the table, this indicates either a faulty gain stage in the PA or low RF input

power to the PA.

1 3

1Reciter 3PA 5Load

216-way cable 4RF Power Meter

TB8100 Calibration Kit User’s Manual Calibrating the Supply Voltage 27

VSWR The VSWR (Voltage Standing Wave Ratio) is monitored at the RF output of

the PA during calibration. The software will not allow calibration into a load

VSWR > 1.3:1. If a calibration step cannot be stored, check that the load

VSWR is <1.3:1. It is recommended that the load should have an input

VSWR <1.2:1.

Calibrating the Supply Voltage

The Calibrate Supply Voltage procedure stores DAC values for a set of

different PA supply voltages. These values are used by the PA’s high and low

voltage alarms and for power foldback and shutdown.

Calibrating the supply voltage is only done if you have replaced the PA control

board or its EEPROM IC. An accredited service center must first re-program

the PA with its product code, PA type, and serial number. All other PA

calibration procedures also become necessary.

Equipment ■Variable voltage power supply

■Made-up adapter cable to connect the PA power input to the power supply,

with a “Chocolate block” screw connector at one end and (for example)

banana plugs at the other.

Important: Do not attempt this procedure without a variable voltage power

supply. You could be left with a PA that will not transmit.

To calibrate the PA power supply voltage

1. Connect the calibration kit to the base station.

2. Connect the variable voltage power supply to the PA as follows. (The PA

can be in or out of the subrack, as long as it is connected via the I2C bus.),

a. Remove the PA power connector from the socket in the PMU.

b. To make sure that you don’t re-connect the power cable with the wrong

polarity, mark the green connector to indicate which side is positive and

which is negative.

c. Remove the PA’s power cable from the green connector and connect it

to the “Chocolate block” screw connector on the made-up cable.

d. Connect the other end of the cable to the variable voltage power supply.

3. Select the PA calibration tab, and double-click Calibrate Supply Voltage.

The Calibrate Supply Voltage wizard appears.

4. Check that everything is connected correctly, and then click Next.

5. Set the power supply to 24.00 V as instructed, and then click Next. The PA

stores the DAC equivalent of the voltage you supplied and the wizard moves

to the next step.

6. Follow the wizard instructions (Steps 3-5) to store DAC values for 26, 30,

and 32 V. If desired, you can click Back to repeat a step.

7. When the wizard indicates that calibration is completed, click Finish.

The icon beside Calibrate Supply Voltage in the PA Calibration tab

indicates that this task is complete.

8. Re-connect the PA’s power cable to the green connector, using the marks

you made to ensure that you connect the wires the right way round.

9. Re-connect the PA to the PMU.

Calibrating the Power Management Unit

There is only one calibration procedure for the PMU: calibrating its output

voltage.

Calibrating the PMU Output Voltage

Calibrating the PMU output voltage adjusts the voltage to be 28.00 V. This

procedure is only carried out when a replacement control card or

microprocessor is fitted to the PMU. Normally, the output voltage will be

accurate without calibration.

Note: Re-calibrating the PMU output voltage may result in it failing

to meet the published specification of +/- 0.5% accuracy. This is

because control cards are calibrated in the factory under half-load,

giving a voltage that is closer to 28.00 V under varying loads.

To calibrate the output voltage

1. Connect the Calibration Kit to the base station (see “Connecting to a

Reciter via the Control Panel” on page 7).

2. Select the PMU Calibration tab.

3. Double-click Output Voltage Calibration. The Calibrate Output

Voltage wizard appears.

4. Connect a digital multimeter to the PMU output and read the output

voltage.

5. Enter the voltage into the PMU Voltage box and click Calibrate.

6. When the wizard indicates that the calibration completed successfully, click

Finish.

TB8100 Calibration Kit User’s Manual Index 29

Index

AC millivoltmeter

see equipment

Antenna VSWR (Voltage Standing Wave Ra-

tio) 25

audio level

calibrating 19, 20

balanced input

calibrating 19

balanced output

calibrating 19

band 1

entering 4

base station

connecting to 7

disconnecting from 7

bias current

required for each power level 24

RF detectors 25

calibration test kit

see equipment

calibration test unit (CTU)

connecting to computer 6

connecting to reciter 6

Tait TBAL0 Base Station Transceiver User Manual TB8100 Calibration Kit User s Manual

Tait Limited Base Station Transceiver TB8100 Calibration Kit User s Manual

Exhibit D Users Manual per 2 1033 c3

Navigation menu

Namespaces

Views

Navigation