Puxing PX-777 User manual

UHF/VHF FM TRANSCEIVER
PX-777/328/338
SERVICE MANUAL
------------------CONTENTS--------------------------
INTRODUCTION……………………………………………………2
GENERAL ................................................................................. 2
REALIGNMENT……………………………………………………..3
TROUBLE SHOOTING GUIDE……………………………………6
TECHNICAL SPECIFICATION ............................................. …7
FUNCTION SPECIFICATION…………………………………….8
CIRCUIT DESCRIPTION ......................................................... 9
SEMICONDUCTOR DATA.............................................……. 16
PARTS LIST............................................................................ 17
BLOCK DIAGRAM …………………........................................ 22
PCB BOARD………………………………………………………23
SCHEMATIC DIAGRAM....................................................... 25

INTRODUCTION
SCOPE OF THIS MANUAL
This manual is intended for use by experienced technicians
familiar with similar types of commercial grade communications
equipment. It contains all required service information for the
equipment and is current as of the publication data. Changes
which may occur after publication are covered by either Service
Bulletins or Manual Revisions. These are issued as required.
ORDERING REPLACEMENT PARTS
When ordering replacement parts or equipment information,
the full part identification number should be included. This
applies to all parts : components, kits, or chassis. If the part
number is not known, include the chassis or kit number of which
it is a part, and a sufficient description of the required
component for proper identification.
PERSONNEL SAFETY
The following precautions are recommended for personnel
safety:
DO NOT transmit until all RF connectors are verified secure
and any open connectors are properly terminated.
SHUT OFF and DO NOT operate this equipment near
electrical blasting caps or in an explosive atmosphere.
This equipment should be serviced by a qualified technician only.
SERVICE
This radio is designed for easy servicing. Refer to the
schematic diagrams, printed circuit board views, and alignment
procedures contained within.
GENERAL
Your Transceiver is an electronic product of exact design and should be treated with care .The
suggestions below will help you to fulfill any warranty obligations and to enjoy this product for many
years.
 Do not attempt to open the unit. Non-expert handling of the unit may damage it.
 When using regulated power supply, take notice of power voltage must be between 6V and 8V to
avoid damaging the unit.
 Do not store the Radio under the sunshine or in hot areas.
High temperatures can shorten the life of electronic devices, and warp or melt certain plastics.
 Do not store the Radio in dusty, dirty areas
 Keep the Radio dry. Rainwater or damp will corrode electronic circuits.
 If it appears that the Radio diffuses peculiar smell or smoke, please shut off its power
immediately and take off charger or battery in the Radio, then contact with PUXING agency.
 Do not transmit without antenna.

2. LCD DISPLAY

3. SELF-PROGRAMMING MODE
For frequency,signal,feature write to the radio