Tait T805 User manual

R805-00-102
Copyright TEL 5/11/96
M805-00 Revision Package
IPN R805-00-102
5/11/96
Introduction Revision package R805-00-102 is the second update to M805-00
A0.
This revision package contains:
• additional information on one updated PCB (the T805-04
backplane PCB IPN 220-01254-04)
• additional information on one new PCB (the T805 front
panel PCB IPN 220-01354-00)
• revisions to most sections in the manual to bring them up
to date and provide additional information.
The List of Effective Pages and Tables Of Contents have also
been updated to reflect these changes.
Contents You can update your M805-00-101 to revision 102 status by sub-
stituting or adding these Revision Package pages as instructed
in the following table:
Section Revision Package
Page Numbers Pages To Replace Add In Sequence After Page
TOC/
LEP 1 to 8 1 to 8 
1 1.5 to 1.8 1.5 to 1.8 
4 4.1 to 4.10 4.1 to 4.10 
5 5.3 to 5.4 5.3 to 5.4 
7 7.1 to 7.18 7.1 to 7.16 
8 8.5 to 8.12 8.5 to 8.12 
9 9.13 to 9.14 9.13 to 9.14 
10 10.3 to 10.6
10.11 to 10.18 10.3 to 10.6 10.11 to 10.18 

13 13.3 to 13.4 13.3 to 13.4 

R805-00-102
5/11/96 Copyright TEL
Additional Revi-
sion Packages Additional revision packages should be ordered from your near- est Tait branch or approved dealer. Quote the Tait Internal Part
Number (IPN R805-00-102) when ordering.
14.1 14.1.1 to 14.1.2 14.1.1 to 14.1.2 
14.2 14.2.1 to 14.2.2 14.2.1 to 14.2.2 
14.3 14.3.1 to 14.3.2
14.3.13 to 14.3.22 14.3.1 to 14.3.2

14.3.12
14.4 14.4.9 to 14.4.10 14.4.9 to 14.4.10 
14.5 14.5.1 to 14.5.6 14.4.14
App. A A1 to A4 A1 to A4 
Section Revision Package
Page Numbers Pages To Replace Add In Sequence After Page

M805-00 1
Copyright TEL 30/09/96
T805 Quasi-Synchronous
Transmission System
Service Manual
Issue 102
October 1996
M805-00-102

2M805-00
30/09/96 Copyright TEL
Head Office
New Zealand
Tait Electronics Ltd
558 Wairakei Road
P.O. Box 1645
Christchurch
New Zealand
Phone: [phone]
Fax: [phone]
Radio Infrastructure Division
535 Wairakei Road
P.O. Box 1645
Christchurch
New Zealand
Phone: [phone]
Fax: [phone]
Australia
Tait Electronics (Aust) Pty Ltd
275 Toombul Road
Northgate 4013
P.O. Box 679
Virginia
Queensland 4014
Australia
Phone: [phone]
Toll Free: 1800 077-112
Fax: [phone]
Canada
Tait Mobile Radio Inc.
Unit 5, 158 Anderson Avenue
Markham
Ontario L6E1A9
Canada
Phone: [phone]
Toll Free: 1 800 890-8248
Fax: [phone]
France
Tait France Sarl
2 Avenue de la Cristallerie
92 316 Sèvres, Cedex
France
Phone: [phone]
Fax: [phone]
Germany
Tait Mobilfunk GmbH
Willstätterstraße 50
D-90449 Nürnberg 60
Germany
Phone: [phone]
Fax: [phone]
Hong Kong
Tait Mobile Radio (HK) Ltd
Room 703A
New East Ocean Centre
9, Science Museum Road
Tsim Sha Tsui East
Hong Kong
Phone: [phone]
Fax: [phone]
New Zealand
Tait Communications Ltd
Unit 4, 75 Blenheim Road
P.O. Box 1185
Christchurch
Phone: [phone]
Fax: [phone]
Singapore
Tait Electronics (Far East) Pte Ltd
4 Leng Kee Road
SIS Building #05-11A
Singapore 159088
Phone: [phone]
Fax: [phone]
Taiwan
Tait Electronics (Taiwan) Ltd
1104, No. 142 Chung Hsiao E. Rd
Sec. 4
Taipei
Taiwan
Phone: [phone]
Fax: [phone]
United Kingdom
Tait Mobile Radio Ltd
Ermine Business Park
Ermine Road
Huntingdon
Cambridgeshire PE18 6YA
United Kingdom
Phone: [phone]
Fax: [phone]
USA
Tait Electronics (USA) Inc.
9434 Old Katy Road
Suite 110
Houston
Texas 77055
USA
Phone: [phone]
Toll Free: 1 800 222-1255
Fax: [phone]

M805-00 3
Copyright TEL 30/09/96
About This Manual
Scope This manual contains general, technical and servicing informa-
tion on the T805 Quasi-Synchronous Transmission System and
covers all Version 2 and earlier software.
Format We have published this manual in a ring binder so that "revision
packages" containing additional information pertaining to new
issues of PCBs can be added as required.
Revision Packages Revision packages will normally be published to coincide with
the release of information on a new PCB, and may also contain
additions or corrections pertaining to other parts of the manual.
If you return the address card at the front of this manual, you
will be notified when revision packages containing new PCB
information and/or text are available. You may then order as
many packages as you require from your local Tait Company.
Revision packages are supplied ready-punched for inclusion in
your manual.
Revision Control Each page in this manual has a date of issue. This is to comply
with various Quality Standards, but will also serve to identify
which pages have been updated and when. Each page and its
publication date is listed in the "List of Effective Pages", and a
new list containing any new/revised pages and their publica-
tion dates will be sent with each revision package.
Any portion of text that has been changed is marked by a verti-
cal line (as shown at left) in the outer margin of the page. Where
the removal of an entire paragraph means there is no text left to
mark, an arrow (as shown at left) will appear in the outer mar-
gin. The number beside the arrow will indicate how many para-
graphs have been deleted.
The manual issue and revision status are indicated by the last
three digits of the manual IPN. These digits start at 100 and will
increment through 101, 102, 103, etc., as revision packages are
published, e.g:
Thus, Issue 103 indicates the third revision to issue 1 and means
that three packages should have been added to the manual. The
issue digit will only change if there is a major product revision,
or if the number of revision packages to be included means that
the manual becomes difficult to use, at which point a new issue
manual will be published in a new ring binder.
PCB Information PCB information is provided for all current issue PCBs, as well
as all previous issue PCBs manufactured in production quanti-
ties, and is grouped according to PCB. Thus, you will find the
parts list, grid reference index (if necessary), PCB layouts and
2
1 0 3
issue status revision status

4M805-00
30/09/96 Copyright TEL
circuit diagram(s) for each individual PCB grouped together.
Errors If you find an error in this manual, or have a suggestion on how
it might be improved, please do not hesitate to contact the Tech-
nical Writer, Tait Radio Infrastructure Division, Tait Electronics
Ltd, P.O. Box 1645, Christchurch, New Zealand.
Technical Information
Any enquiries regarding this manual or the equipment it describes should be addressed
in the first instance to your nearest approved Tait Dealer or Service Centre. Further
technical assistance may be obtained from the Customer Support Group, Tait Radio
Infrastructure Division, Tait Electronics Ltd, Christchurch, New Zealand.
Updating Equipment And Manuals
In the interests of improving performance, reliability or servicing, Tait Electronics Ltd
reserve the right to update their equipment and/or manuals without prior notice.
Copyright
All information contained in this manual is the property of Tait Electronics Ltd. All
rights are reserved. This manual may not, in whole or part, be copied, photocopied,
reproduced, translated stored or reduced to any electronic medium or machine readable
form without prior written permission from Tait Electronics Ltd.
Ordering Tait Service Manuals
Service Manuals should be ordered from your nearest Tait Branch or approved Dealer.
When ordering, quote the Tait Internal Part Number (IPN) and, where applicable, the
version.
Date Of Issue
IPN M805-00-102 T805 Quasi-Synchronous Transmission System Service Manual
Issue 100 published (as A0) June 1993
Issue 101 published June 1995
Issue 102 published October 1996

M805-00 5
Copyright TEL 30/04/95
Table Of Contents
This manual is divided into 14 Sections and two Appendices, as listed below. There is a
detailed table of contents at the start of each Section.
Section Title
1 General Information
2 System Description
3 Circuit Operation
4 ASP Card Operation
5 Quasi-Synchronous Operation With Audio Distribution Net-
works
6 Introduction To Servicing
7 Initial Programming & Adjustment
8 Functional Tests
9 Fault Finding
10 T805-04 Backplane
11 T805-06 1U Rack
12 T805 System Controller
13 Commissioning Tests
14 PCB Information
Appendix A Glossary Of Terms
Appendix B Decimal-Hex-Binary Conversion Table

6M805-00
30/09/96 Copyright TEL
List Of Effective Pages
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Copyright TEL 30/09/96
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M805-00 General Information 1.5
Copyright TEL 30/09/96
Clock Frequency .. 40.00MHz
A/D Sampling Rate .. 11.57kHz
ASP Rack Frame Housing .. 483mm, 1U or 6U high
ASP Card Dimensions .. 233mm x 210mm
Maximum Number Of System Cards
Per Rack Frame .. 9
Power Supply Requirements2.. +13.8V DC supply capable of supply-
ing 9A per rack
Operating Temperature Range .. 0°C to +55°C
1.2.4 Audio Interface Card - TSGM
Maximum Number Of TSGMs Per Network .. 2 (main plus back-up)
Audio Interfaces:
Inputs:
Quasi-Synchronous Audio .. 600Ωbalanced via rack
(From RIC)
External CTCSS (Optional) .. 47kΩbalanced
Outputs:
LF Training Signal/CTCSS .. 600Ωbalanced via rack
HF Training Signal/Q-S Audio .. 600Ωbalanced via rack
Audio Bandwidth .. 67Hz to 3kHz or 67Hz to 2550Hz
(depending on configuration)
Signal To Noise Ratio .. >50dB
Distortion .. <1%
Audio Input And Output Levels .. -10dBm nominal into a 600Ω
balanced load
Maximum Audio Input And Output Levels .. 0dBm into a 600Ωbalanced load
Digital Inputs .. "ICCS" (breakout)
Switching Outputs (Open Collector) .. "DIGOUT" (training pulse)
Communication With Q-S Controller .. RS-485 2400 baud

1.6 General Information M805-00
30/09/96 Copyright TEL
1.2.5 Audio Interface Card - LEM
Maximum Number Of LEMs Per System .. 222
Maximum Number Of LEMs Per Network .. 222
Audio Interfaces:
Inputs:
High Frequency Training
Audio/Quasi-Synchronous Audio .. 47kΩbalanced
Low Frequency Training
Audio/CTCSS .. 47kΩbalanced
Test Receiver Audio .. 600Ωbalanced via rack
RIC (Breakout) Audio .. 600Ωbalanced via rack
Outputs:
LEM Audio Out .. 600Ωbalanced
Audio Bandwidth .. 300Hz to 3kHz or 67Hz to 3kHz
depending on input or output
Signal To Noise Ratio .. >50dB
Distortion .. <1%
Input And Output Levels .. -10dBm nominal into a balanced load
Maximum Audio Input And Output Levels .. 0dBm into a 600Ωbalanced load
Digital Inputs .. "GPS" (sample training tone)
.. "ICCS" (breakout)
Communication With Q-S Controller .. RS-485
1.2.6 Audio Interface Card - AIM
Audio Interfaces:
Input:Audio In .. 600Ωbalanced via rack
Output:
Audio Out .. 600Ωbalanced via rack
Bandwidth:
Input .. 67Hz to 2550Hz (speech, CTCSS)
67Hz to 3kHz (speech, CTCSS and
control signals)
Output .. 350 Hz to 2833Hz (speech, CTCSS)
350Hz to 3kHz (speech, CTCSS and
control signals)

M805-00 General Information 1.7
Copyright TEL 30/09/96
Signal To Noise Ratio .. >50dB
Distortion .. <1%
Input And Output Levels .. -10dBm nominal into a balanced load
Maximum Audio Input And Output Levels .. 0dBm into a 600Ωbalanced load
Digital Inputs/Outputs .. "ICCS" (transmitter key input)
Communication With Quasi-Synchronous
System Controller .. not required
Control Of Operating Modes .. audio signalling down the line
1.2.7 Audio Interface Card - ARM
Audio Interfaces:
Input:Audio In .. 600Ωbalanced via rack
Outputs:
Audio Out (+ Optional Keytone) .. 600Ωbalanced
CTCSS .. 600Ωbalanced
Audio Bandwidth:
Input (Speech, CTCSS & Control Signals) .. 350Hz to 3kHz
Outputs:
Audio Out .. 67Hz to 2550Hz
CTCSS .. 67Hz to 300Hz
Keytone (Optional) .. 2970Hz
Signal To Noise Ratio .. >50dB
Distortion .. <1%
Input And Output Levels .. -10dBm nominal into a balanced load
Maximum Audio Input And Output Levels .. 0dBm into a 600Ωbalanced load
Digital Outputs (Open Collector) .. "DIGOUT" (transmitter key)
Communication With Quasi-Synchronous
System Controller .. not required
Control Of Operating Modes .. audio signalling down the line

1.8 General Information M805-00
30/04/95 Copyright TEL
1.2.8 T805-04 Backplane
Maximum Number Of ASP Cards Per Rack .. 9
Power Supply2.. +13.8V DC capable of supplying 9A
per rack
Audio Interfaces .. buffer amps for linking to next rack
in series
Termination Types:
Audio .. terminal blocks
RS-485 .. 9-pin D-range
Series Link To Other Racks .. 34-way IDC
1.2.9 T805-06 1U Rack
Maximum Number Of ASP Cards Per Rack .. 1
Type of ASP Cards To Be Fitted .. T805-01 AIM
.. T805-01 ARM
Power Supply2.. +13.8V DC capable of supplying 1A
Input Signals .. Telecom 4W3
.. monitor receiver audio
Output Signals .. Telecom 4W
.. transmit audio
.. transmit CTCSS/low frequency
training tones
Termination Types:
Audio .. terminal blocks
Telecom .. via Line Barrier Unit3
1.2.10 AIM-ARM Communications Link
Type Of Link .. Telecom 4-wire
Line Type .. private speech band circuits of
keyline-3 specification or similar
Interface3.. line barrier units
(type CYFAS 88/05073)

M805-00 ASP Card Operation 4.1
Copyright TEL 30/09/96
4 ASP Card Operation
This section provides a functional description of the T805 Audio Signal Processing
(ASP) cards, i.e. TSGM, LEM, AIM and ARM. Each of these cards has the same hard-
ware but different operating software.
The following topics are covered in this section.
Section Title Page
4.1 T805-03 Test Signal Generator Module (TSGM) 4.3
4.2 T805-02 Line Equaliser Module (LEM) 4.6
4.3 T805-01 Audio Inversion And Recovery Modules (AIM &
ARM) 4.7
4.3.1 T805-01 Audio Inversion Module (AIM) 4.7
4.3.1.1 Local Mode 4.8
4.3.1.2 Remote Mode 4.8
4.3.2 T805-01 Audio Recovery Module (ARM) 4.9
4.3.2.1 Remote Mode 4.9
4.3.2.2 Local Mode 4.10
Figure Title Page
4.1 TSGM Block Diagram 4.3
4.2 LEM Block Diagram 4.6
4.3 AIM Block Diagram 4.7
4.4 Example Of Signals Fed Into An AIM 4.8
4.5 Example Of Inverted Signals Output From An AIM 4.8
4.6 ARM Block Diagram 4.9
4.7 ARM Operation When In Remote Recovery Mode 4.10
Table Title Page
4.1 Assignment Of TSGM IDs According To Network 4.5

4.2 ASP Card Operation M805-00
30/04/95 Copyright TEL

M805-00 ASP Card Operation 4.3
Copyright TEL 30/09/96
4.1 T805-03 Test Signal Generator
Module (TSGM)
Figure 4.1 TSGM Block Diagram
The TSGM's primary functions are to generate the test tones for the equaliser training
process and to distribute audio to the LEMs during normal operation. It can also sup-
ply a 2970Hz tone for keying the system transmitters.
The TSGM has two audio inputs:
- the first is for speech from the source;
- the second is for the optional external source of CTCSS tones.
Note: If required, the TSGM may be programmed to internally generate its own
CTCSS tone and to optionally generate reverse phase burst CTCSS.
The TSGM has two audio outputs:
- output 1 is used for training tones/speech/key tones in the 300Hz to 3kHz fre-
quency range (HF audio);
- output 2 is used for training tones/CTCSS in the 67 to 300Hz frequency range
(LF audio).
In addition there is a digital output called "DIGOUT" which provides the synchronisa-
tion pulse or "start gun" required by the LEMs during the training process.
When the system is operating normally in pass mode (i.e. not in the training mode), the
TSGM passes the normal speech audio (0-3200Hz for software v2.09, v2.10 & v2.11;
0-2550Hz for v2.12 & v2.13) from the appropriate input (depending on system configu-
ration) to output 1, and after that to all the LEMs. The signal path followed will depend
on the system type to which the Quasi-Synchronous system is connected (refer to Sec-
tion 5). The CTCSS tone (67-300Hz) for the system is sourced from audio output 2 and
follows a different path from that of the speech.
All speech audio for the Quasi-Synchronous system is passed through the TSGM. For
systems which have the AIM/ARM combinations fitted, two or three methods of key-
ing the transmitters may be used, depending on the software version used:
A/D
Audio
amps
Audio
buffer
Audio
buffer Audio amps
A/D
Audio
buffer
Audio
buffer Audio amps
DSP
processor
D/A
D/A
Audio
amp
Audio
amp
Electronic
relay
Electronic
relay
1
3
4
2
1
2
Digout
N/C
HF audio
(speech or
training tones)
LF audio
(CTCSS or
training tones)
Start gun
pulse
Speech
audio
N/C
External CTCSS
(optional)
ICCS
Tx key
(v2.12 & later)

4.4 ASP Card Operation M805-00
30/09/96 Copyright TEL
1. Taking the ICCS input of the TSGM to logic "1" will cause it to generate a keytone
of the correct level. This is detected by the AIM, initiating the inversion/recovery
process and keying the transmitter connected to the ARM. The tone will continue
for as long as the input is at logic "1", and will cease 250ms after the input has
fallen to logic "0" (unless reverse phase burst is selected, in which case the tail time
is 350ms - see Note 3 below). The ICCS inputs to the AIMs are left unconnected.
Note 1: This method is available with TSGM software v2.12 and later.
2. An externally generated 2970Hz tone at a level of -23dBm may be added to the
TSGM audio input. This tone is detected by the AIM, initiating the inversion/
recovery process and keying the transmitter connected to the ARM.
Note 2: For TSGM software versions 2.10 and 2.11 this tone can be mixed with the
audio fed into input 1. For software versions 2.12 and later this tone is fed
separately into input 2.
3. Taking the ICCS input of the AIM to logic "1" will place it in inversion mode and
the transmitter will be keyed by the associated ARM, independent of the presence
of a 2970Hz tone.
The CTCSS tone from audio output 2 may be generated internally, the frequency being
programmed via DIP switches on the board. Alternatively, the CTCSS may be exter-
nally supplied, but must be passed into the TSGM via input 2 so that it still exits from
audio output 2.
Note 3: For TSGM software versions 2.12 and later internal CTCSS is generated only
when the ICCS input is at logic "1", and is stopped when the ICCS input
becomes logic "0".
Versions 2.12 and later support reverse phase burst of internal or external
CTCSS, where, after a transition from logic "1" to logic "0" of the ICCS input,
the output phase of the CTCSS is reversed 180 degrees. Use of reverse phase
burst continues CTCSS for 100ms after ICCS falls to logic "0" and continues
the 2970Hz keytone for 250ms after cessation of CTCSS. The use of reverse
phase burst CTCSS is selectable by DIP switch.
The training sequence is controlled by the System Controller but performed by the
TSGM(s) and LEMs. Each time the training of an LEM begins, the TSGM sends out a
start gun (synchronisation) pulse via its "DIGOUT" output. This is passed to the "GPS"
input of all the LEMs, but only the LEM being trained will respond to it.
There is only one TSGM in a typical network. However, a second one may be added to
serve as a back-up if the other fails (if the TSGM fails, all audio is lost as it is routed
through the TSGM).
The TSGMs are assigned addresses according to the network to which they are con-
nected (see Table 4.1) and have their RS-485 transceivers permanently enabled for com-
municating with the System Controller.

M805-00 ASP Card Operation 4.5
Copyright TEL 30/09/96
Table 4.1 Assignment Of TSGM IDs According To Network
If the system TSGM fails, the RS-485 transmitter is automatically disabled to prevent
corruption of the communications line. The audio I/O is also disabled to prevent inter-
ference. Because the failed TSGM is unable to answer polls, the System Controller will
then instruct the other TSGM (if fitted) to connect its audio lines and thus become the
system TSGM.
For more information on control of the TSGM by the System Controller, refer to the Sys-
tem Controller manual.
Network Number TSGM ID Numbers (Decimal)
1
2
3
4
5
6
7
8
223, 224
225, 226
227, 228
229, 230
231, 232
233, 234
235, 236
237, 238

4.6 ASP Card Operation M805-00
30/09/96 Copyright TEL
4.2 T805-02 Line Equaliser Module
(LEM)
Figure 4.2 LEM Block Diagram
The LEM applies the audio signal equalisation (gain, phase and group delay) for the
transmitter to which it is associated. An LEM may be connected to only one transmitter.
Like the TSGM, the LEM has two modes of operation: training and normal.
The training procedure for the LEM is controlled by the System Controller. Training
audio consisting of high frequency (HF) training audio (300-2550Hz) and low frequency
(LF) training audio (45-300Hz) is passed from the TSGM into the LEM to be trained
where it is combined, processed and passed to the transmitter. A strategically located
monitor receiver passes the received audio back to the LEM where it is compared to the
reference tones (from the reference LEM). The characteristics (gain, phase and group
delay) are then modified (equalised) by the LEM to produce the same response as the
reference. When training of that LEM is complete, the speech audio passed into the
LEM is modified according to this characteristic.
The TSGM signals to all LEMs the beginning of each training sequence (which is initi-
ated by the system controller) via the "GPS" input of each LEM. Only the LEM being
trained will respond to it.
The audio inputs and outputs of the LEM may be configured in various ways, the sys-
tem configuration defining how these are selected (refer to Figure 4.2 and Section 5).
Under normal operating conditions the LEMs operate in the Quasi-Synchronous
("equalised") mode, but any LEM may be removed from Quasi-Synchronous operation
to operate independently if required ("breakout mode"). Control of this mode is via the
"ICCS" input of the appropriate LEM; normally held at logic "0", if pulled to logic "1"
(+5V) the LEM may be operated outside the Quasi-Synchronous system (i.e. the audio
being passed into the LEM is no longer modified and is usually transmitted on a differ-
ent frequency). An auxiliary audio input may be used for a different audio path when
this mode is invoked. If the training procedure is being carried out at the time the "brea-
kout" occurs, training is aborted. For more information on the training procedures, refer
to the System Controller manual.
A/D
Audio
amps
Audio
buffer
Audio
buffer Audio amps
A/D
Audio
buffer
Audio
buffer Audio amps
DSP
processor
D/A
D/A
Audio
amp
Audio
amp
Electronic
relay
Electronic
relay
1
3
4
2
1
2
HF audio
(speech or training tones)
LF audio
(CTCSS or training tones)
Breakout audio
(ADC-2 system only)
Monitor receiver
audio N/C
GPS ICCS
Start gun (synchronisation)
pulse
Breakout
control
Combined HF and
LF audio