PYE Beaver M254 User manual
Service Manual
Pye Telecommunications Ltd
Beaver
VHF FM Mobile
Radiotelephone
Types M254 & M256
Publication Ref No.TP271
WARNING
Certain semiconductor devices used in this equipment con-
tain 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.
BEAVER
VHF FM MOBILE RADIOTELEPHONE
TYPES M254 AND M256
SERVICE MANUAL
ISSUE 1 MARCH 1976
E TELECOMMUNICATIONS LIMITED
CAMBRIDGE
ENGLAND
nted in England
©1976
TP271
AMENDMENT LIST
Changes made to the equipment described in this publication are published as amendments
which are dated and consecutively numbered.
Reprints 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 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 publication the amendment numbering will
recommence with No. 1.
Amend't No.
Date
Initials
Remarks
1
October 1978
Incorporated on Reprint
ERRORS & OMISSIONS
The usefulness of this publication 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:—
Please quote:
a)
Title of publication
b)
TP No. and issue No.
c)
Last amendment No. received
d)
Page and/or Fig. No. in error
Please send to.
Pye Telecommunications Ltd.
Publications Dept.
Mariners Way
Cambridge CB4 1 BN
England
CONTENTS
Page
SECTION 1
GENERAL INFORMATION
Summary of Data
1.1
Introduction
1.3
Equipment Variations
1.4
Module Identification
1.5
SECTION 2
INSTALLATION AND OPERATION
Pre-Installation Checks
2.1
Netting Procedures
2.2
Test Frequency Crystal Information
2.2
Contents List (Installation Items)
2.2
Installation Procedure
2.3
Antenna Information
2.12
Operation
2.14
SECTION 3
TECHNICAL DESCRIPTION
Receiver Circuit Summary
3.1
Transmitter Circuit Summary
3.2
Power Distribution and Switching
3.3
12,5V Restrictor and 10V Regulator
3.4
Control Panel (Front Mount)
3.4
Control Unit (Remote Mount)
3.4
RF Front End
3.6
Oscillator Modules
12-channel Oscillator
3.7
Single Channel Oscillator
3.8
6-channel Oscillator
3.9
PA Module
3.10
Antenna Filter and Changeover Relay
3.10
Receiver Oscillator Multiplier
3.12
Transmitter Exciter
3.12
IF Amplifier and Squelch
3.15
Transceiver Audio (Receiver Part)
3.16
Transceiver Audio (Transmitter Part)
3.17
TP271/1
CONTENTS (Continued)
Page
SECTION 4
SERVICING
PRECAUTIONS AND GENERAL INFORMATION
Routine Frequency Adjustment
4.1
'Pozidriv' Screws
4.1
Griplets
4.1
Component Removal From PWBs Fitted with Griplets
4.1
Servicing Compounds
4.1
Soldering
4.1
Printed Wiring Boards
4.2
Replacement of Plug-in Modules
4.2
Use of FM Beaver Test (Extension)
Assemblies Kit
4.2
Fault Finding - Integrated Circuits
(IC's) and Thick Film Circuits (TFs)
4.2
Antenna Loading
4.2
CONSTRUCTION
4.4
EQUIPMENT ACCESS
4.5
Tools Required
4.5
Procedure
4.5
Module Replacement
4.6
TEST EQUIPMENT
4.8
CRYSTAL INFORMATION
4.9
ALIGNMENT PROCEDURE AND PERFORMANCE CHECKS
Test Points (TPs)
4.9
Measuring Points (MPs)
4.9
Identification of Modules and Components
4.10
Signal Generator Levels
4.10
Intermediate Frequencies
4.10
Multiple Channel Equipments
4.10
Multi meter
4.10
General Preliminary Checks and Adjustments
4.10
Receiver Alignment
4.10
Transmitter Alignment
4.12
CHANGE OF FREQUENCY PROCEDURE
4.14
RECEIVER PERFORMANCE CHECKS
4.14
RF Sensitivity
4.14
Audio Sensitivity
4.14
Audio Power Output
4.14
Bandwidth
4.14
Squelch
4.14
Frequency Count
4.15
Sinad Measurement
4.15
TP271/1
This manual suits for next models
1
Table of contents
Other PYE Cordless Telephone manuals
