PYE OLYMPIC M201 User manual

Service Manual
Pye Telecommunications Ltd
OLYMPIC Mobile
Radiotelephone Type M201
Publication Ref No. TP169

WARNING
Certain semiconductor devices used in this equipment
contain Beryllium Oxide. If inhaled, dust from this oxide
can be toxic.
No danger can arise from normal handling but no attempt
should be made to tamper with these devices.
They should not be discarded with industrial or domestic
waste.
This Service Manual is for the maintenance of Pye Telecommunications equipment.
The performance figures quoted are typical and are subject to normal manufacturing and service
tolerances.
The right is reserved to alter the equipment described in this manual in the light of future technical
development.
OLYMPIC
VHF AM MOBILE RADIOTELEPHONE
TYPE M201
ISSUE 2
SERVICE MANUAL
MAY 1978
PYE TELECOMMUNICATIONS LIMITED 
CAMBRIDGE 
ENGLAND
Printed in England  © 1976 
TP169

a)
b)
c)
d)
Please send to:
Pye Telecommunications Ltd.
Publications Dept.
Mariners Way
Cambridge CB4 1 BN
England
Please quote:
Title of manual
TP No. and issue No.
Last amendment No. received
Page and/or Fig. No. in error
AMENDMENT LIST
Changes made to the equipment described in this manual are published as amendments which
are dated and consecutively numbered.
Reprints of the manual will incorporate all the amendments to date and an entry to this effect
will be recorded on the amendment list below. Each page affected by amendment action will bear
the amendment number as a suffix to the manual reference number eg TP123/4 indicates that the
page has been corrected by amendment number 4.
Should it be necessary to raise the issue of a manual the amendment numbering will
recommence with No. 1.
Amend't No.

Date

Initials

Remarks
ERRORS & OMISSIONS
The usefulness of this Service Manual depends upon its accuracy. Whilst every endeavour has been
made to minimise errors, some may exist. It is therefore requested that any errors or omissions
noted be advised as follows.—

CONTENTS
Page
SECTION 1
 GENERAL INFORMATION
Summary of Data 
1.1
Introduction 
1.3
Equipment Variations 
1.4
Module Identification 
1.6
SECTION 2 
INSTALLATION AND OPERATION
Pre-installation checks 
2.1
Netting Procedures 
2.1
Test Frequency Crystal Information 
2.2
Contents List (Installation Items).

2.2
Equipment Required 
2.2
Procedure 
2.3
12V Supply 
2.5
24V Supply 
2.5
Amplifier A200 
2.6
Antenna Information 
2.8
Operation 
2.11
SECTION 3 
TECHNICAL DESCRIPTION
Receiver Circuit Summary

3.1
Transmitter Circuit Summary

3.2
Power Supplies and Switching

3.3
Receiver RF Unit (1)

3.4
Receiver Oscillator (8)

3.6
Receiver Multiplier (5)

3.6
10,7 MHz Crystal Filter

3.6
IF Amplifier, Detector, and AGC Module (2)

3.7
Noise Limiter, High and Low-pass Filter (3)

3.8
Squelch IF and Delayed AGC Module (6)

3.8
AF Amplifier Module (4)

3.10
Noise Squelch Module (7)

3.10
Low Power Transmitter Audio Module (9)

3.11
High Power Transmitter Modulator Module (17)

3.12
Transmitter Oscillator (8)

3.12
Transmitter Multiplier Module (10)

3.13
PA Module (11)

3.14
Antenna Filter Module (13)

3.16
Switching Module (12)

3.16
Regulator Module (16)

3.17
Receiver and Transmitter Oscillator Module (8) - Single Channel

3.17
Receiver and Transmitter Oscillator Module (18) - 12 Channel

3.18
Receiver and Transmitter Oscillator Module (18) - 6 Channel

3.18

Page
SECTION 4  SERVICING
Precautionary Notes and General Information
 4.1
Construction  4.2
Equipment Access  4.3
Module Replacement 
4.5
Crystal Information

4.5
Test Equipment  4.6
Alignment Procedures and Performance Checks 
4.7
Receiver Alignment

4.9
Receiver Performance Checks 
4.11
Transmitter Alignment 
4.12
Transmitter Performance Checks 
4.14
Fault Location Checks - Transmitter 
4.14
Detailed Signal Analysis of Receiver

4.16
Fault Location Checks - Receiver

4.18
SECTION 5 
PARTS LIST
Notation 
5.1
Ordering of Spare Parts

5.1
Abbreviations

5.1
Miscellaneous Items
 5.2
Installation Items
 5.2
Main Unit 
5.3
RF Unit (1)  5.4
IF Amplifier, Detector and AGC Module (2) 
5.7
Noise Limiter, High and Low-pass Filter Module (3)  5.8
AF Amplifier Module (4) 
5.9
Receiver Multiplier Module (5) 
5.9
Squelch IF and Delayed AGC Module (6)

5.10
Noise Squelch Module (7)

5.11
Oscillator Module (8)

5.11
Low Power Tx Audio Module (9) 
5.12
Tx Multiplier Module (10)

5.13
Transmitter PA Module (11) 
5.14
Switch Module (12) 
5.17
Antenna Filter Module (13) 
5.17
Motherboard (15) 
5.18
10V Regulator Module (16)

5.18
High Power Tx Modulator Module (17) 
5.19
Optional Servicing Accessories 
5.20
SECTION 6  DIAGRAMS
See List of Illustrations

LIST OF ILLUSTRATIONS
Fig. 2.1
Fig. 2.2
Fig. 2.3
Fig. 2.4
Fig. 2.5
Fig. 2.6
Fig. 3.1
Fig. 3.2
Fig. 3.3
Fig. 4.1
Fig. 4.2
Fig. 4.3
Fig. 4.4
Fig. 5.1
Fig. 6.1
Fig. 6.2
Fig. 6.3
Fig. 6.4
Fig. 6.5
Fig. 6.6
Fig. 6.7
Fig. 6.8
Fig. 6.9
Fig. 6.10
Typical Installation
Connection of 12V supply
Connection of 24V supply
Connection of Amplifier A200
Basic Installation Diagram
Ancillary Items
Receiver Block Diagram
Transmitter Block Diagram
Power Supply Block Diagram
Main Unit Interior View
Diode Probe Circuit Diagram
Test Extension Assemblies Kit
Audio Test Lead
Main Unit - Exploded View
Front and Rear Views of Equipment
Control Module - Component Location Diagram
Motherboard (AT27893) - Complete Component Location Diagram
Motherboard - Receiver Module Locations
M201 Receiver Circuit
Motherboard - Transmitter Module Locations
M201 Transmitter Circuit
Earlier Module PWBs
Circuit Variation - Noise Squelch Module
Motherboard (AT27589) - Complete Component Location Diagram
Page
2.4
2.5
2.5
2.6
2.7
2.9
3.1
3.2
3.3
4.3
4.7
4.9
4.17
5.23

SECTION 1
GENERAL INFORMATION
SUMMARY OF DATA
The Olympic M201 complies with all relevant British Post Office Engineering Department
Specifications and requirements, and will meet all relevant international specifications.
General
Operation
Modulation
Frequency Bands
Power Supply
Weight
A3, single or two-frequency simplex
Amplitude
Band A 148-174 MHz
Band E  68-88 MHz
Band C 117-137 MHz
Band M1 105-108 MHz transmitter
Band M2 138-141 MHz receiver
Band E  68-88 MHz transmitter
Band P8 96-106 MHz receiver
12,5 kHz (S)
25 kHz (V)
Single, 1 to 6, and 1 to 12 channels available
±0,5% of mean operating frequencies
—30°C to +60°C ambient
Standard; ±1OPPM over the temperature range —10°C
to +55°C. Alternative stabilities are available to meet
climatic and mandatory requirements.
12V (nominal) DC supply, positive or negative ground
24V operation available using separate regulator unit
(VR200)
Receive (standby) 250mA approx.
Transmit 3A approx.
OFF/ON Switch
SQUELCH
VOLUME
CHANNEL Selector (1 to 6, and 1 to 12 channel
versions) not fitted to single channel versions
Power On
Transmit
Main Unit:-
246mm wide x 185mm deep x 64mm high
Speaker Unit:-
146mm wide x 67mm deep x 95mm high
Main Unit — 2,3 kg
Speaker Unit — 0,55kg
Channel Spacing
No. of Channels
Switching Bandwidth
Operational Temperature Range
Frequency Stability
Current Consumption
Operator Controls
Indicator Lamps
Dimensions
1.1

Optional Extras
1 to 6, and 1 to 12 channels
24V Regulator (VR200)
25W RF Power Amplifier (A200)
Loudspeaker/Microphone
Range of Selective Call Modules*
*Details available on application
50Q
1W for 0,5uV PD signal input, modulated 30% at
1 kHz
10 db at 0,611V PD signal input, modulated 30% at
1 kHz
2,5W with less than 10% distortion, modulated 30%
at 1 kHz
Receiver
Input Impedance
Sensitivity
Signal/Noise Ratio
Audio Output
Spurious Response Attenuation 
At least 85 db (Image at least 70 db)
Squelch

Electronic, fully noise compensated.
Threshold sensitivity equal to or less than 0,4uV PD
with full 6 db range of adjustment above threshold
level.
Automatic Gain Control 
The output does not increase by more than 6 db when
the input is increased from 0,511V to 0,5V PD.
Transmitter
Output Impedance
Power Output
Spurious Outputs
Modulation Response
50P
6W min, A, C and M Bands
8W min, E, Band at 13,8V DC input
(25W with separate power amplifier A200)
Each less than 2,51.W at antenna socket
Typically +1 to —3 db between 300 Hz and 2,5 kHz
relative to 1 kHz.
Typical figures based on normal operating conditions. Pye policy is one of continuous
improvement, therefore the right is reserved to change specifications without notice.
1.2

INTRODUCTION
Main Unit
The Olympic M201 is a front mount AM VHF mobile radiotelephone designed for two-way
communication between a vehicle and a base station.
The main unit operates on fixed crystal-controlled frequencies in the range 68 MHz — 174 MHz,
using either single frequency or two frequency simplex.
Single channel and multiple channel versions are available. In multiple channel sets provision is
made for up to 12 communication channels spaced at either 12,5 kHz or 25 kHz within ±0,5% of the
centre frequency. The channel spacing can be changed by replacing the 10,7 MHz filter.
The transmitter generates a modulated carrier of between 6 watts and 8 watts, depending on
frequency, into a 50Q load. An add-on RF amplifier (A200) is available which increases the output
to 25W.
The receiver delivers 2,5 watts audio power with less than 10% distortion into a 352 load.
The power supply is 12V DC nominal, but a 2 4 / 1 2V regulator (VR200) is available for use
with 24V DC systems.
The equipment consists of a rugged, lightweight main unit (featuring plug-in modules), an
external loudspeaker and fist microphone, or a combined microphone/loudspeaker assembly.
Space provision is made for any one of a range of selective signalling facilities; up to two
additional facilities can be added by means of the 15-way socket mounted on the back wall of the
main unit casing.
1.3

OPTIONS

1. 
Microphone/Loudspeaker
(a)
Fist Microphone and External Loudspeaker
(b) Microphone/Loudspeaker Assy.

*2. 
Selective Call Facilities
(a) Standard Function — no Selective Call Module. Blanking Plate fitted over frame
aperture.
(b)
Single Selective Call Facility — Internal Module fitted.
(c)
Two (or three) Selective Call Facilities—
Internal Module fitted.
External Socket provided and either one or two External Modules fitted.
Blank Module required with External Socket.
NOTE: * It is necessary to link Mother Board and External Socket pins for certain
Facility requirements. Linkage details are given in Section 4 — Servicing.
EQUIPMENT VARIATIONS
Equipment Label
The sub-assemblies fitted to an equipment will vary according to the role in which it is used.
The complement of sub-assemblies for any particular equipment is indicated by a code number
shown on the Equipment Label (together with the catalogue and serial numbers) attached to the
main unit frame assembly. A typical equipment number is given below.
M 201
01 0 0
1 S AO AO 6 00 00
I
Catalogue
Installation Not Function
Tx
No of
Secondary
Number
Items Used Band
Channels Options
Frequency Label
The transmit and receive frequencies for each channel, when known, are shown on the
Frequency Label attached to the main unit frame assembly.
Should the equipment be supplied less crystals, it should be checked on the recommended
test frequencies as detailed under 'Test Frequency Crystal Information' in Section 2.
Market Code
01

Standard Production
Market

No. of
 Not 
Channel
Code

crystalled  Used

Spacing
channels

Rx
 Primary

Band  Options
1.4