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.

REALIGNMENT
1. MODE:
USER MODE: For normal use, when turn on enter this mode.
PC MODE: used to read and program radio.
SELF-PROGRAMMING MODE: Hold down [MONI] and [menu] key
accomplished by turning on the VOL/POWER switch until “SELF” displays.
2.

2. LCD DISPLAY

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

TECHNICAL SPECIFICATION
General
Frequency Range 136 ―174MHz，350—390MHz，400—
470MHz,245Mhz
Working Temperate －20℃―＋50℃
Operating Voltage DC 7.2V
Operate Mode Simplex or Semi-duplex
Channel spacing 25Khz/12.5Khz
Dimension 100mm×55mm×32mm (Not included Antenna)
Weight 220g (Including battery)
Antenna impedance 50Ω
Transmitter
Frequency Stability ±2.5PPM
Output Power 5W/4W ±0.5W
Max Frequency Deviation ≦5KHz
Audio Distortion ≦3%
Modulation Character +3dB—-3dB
Adjacent Channel Power ≥65dB
Spurious Radiation ≤7.5UW
Occupied Bandwidth ≤16KHz
Receiver
RF Sensitivity ＜0.2UV
Audio Distortion ≦3%
Audio Response +2dB—-10dB
Adjacent Channel Selectivity ≥60dB
Intermodulation Rejection ≥60dB
Spurious Response ≥60dB
Blocking ≥80dB

CPU PIN FUNCTION PX-777
ITEM DESCRIPTION I/O FUNCTION
1CLK ROM I/O CLOCK AND EEPROM
2D0 O Key scan output
3D1 O Key scan output
4D2 O PLL clock port/Key scan output
5D3 O PLL data port/Key scan output
6PLL CS O PLL CS port
7LAMP2 O Lcd/backlight control output
8K1 I Key scan input
9K2 I Key scan input
10 K3 I Key scan input
11 K4 I Key scan input
12 AVDD MPU+5MV
13 RX0 O IF output control port
14 RX1 I IF input control port
15 TX1 I MIC input control port
16 TX0 O MIC output control port
17 BEEP/QT O BEEP output /CCTCS tone signal output
18 ACC MPU power filter
19 AVSS Connect to VSS
20 APC/TUNE O Automatic power &frequency automatic gain output
21 AT X O Transmitter data output select control
22 AR X I Receiver data input/audio amplifier adjustment input
23 BATT Test O Battery check /Reset
24 VOX I VOX input
25 AN SQL I Squelch signal input port
26 OSCin I Internal oscillator input
27 OSCout O Internal oscillator output
28 VSS GND
29 EN1 I Encoder data input
30 EN2 I Encoder data input
31 MONI I Monitor key input
32 Reset I CPU reset port
33 Vdd +5V power supply
34 5TC O TX power supply control output
35 LED G O LED green
36 TXD/LED R O RX232 output/ LED red
37 AFC O Audio amplifier control input
38 5CC O Power supply control output
39 P-AMP O Audio amplifier power supply control output
40 N/W/LD O Unlock detection
41 PTT/RX D I PTT key input/RX232 input
42 HT1621 CS I LCD CS port
43 LAMP1 O Backlight control output
44 DQT O DTC audio signal output

FootprintComment
Quantity
容类 备注
C0402 0.5P 2 C332C349
C0402 1P 1 C231
C0402 1.5P 1 C346
C423C456C315C317_2C313_2C175
C535C536C537C538C315_2C314_2
C416C415 CAP CAP C593 CAP
C387_1C318_1C316_2C312_2C326_1C227
C121C132C135C133C142C144
C156C223C222C322C612 CAP
R808C386_1C146C145C176C122
C123C455C515
C413C269C254 C610C451
C623 CAP C633C529C528C613
C450C665_1C105C581C520C701
C174C181C244C247C321C351
C668C454C621 CAP C594C301
C514C392C391
CAP CAP C257C268C266C267
C411C453C202C203C561C271
C663_1 C388_1C319_1C250 CAP
C103C101C573C571C511C521
C182C208C316 CAP C354C662
CAP C302C418C102C147C661
C201C131
C0402 105P 4 C517C611C609 C664
C263C255C361C363C362C213
C348C330C331
C0402 120P 1 C259
C0402 12P 3 C224C241C359
C0402 15P 1 C113
C0402 18P 3 18NHC523C246
C0402 1P 2 C327 C329
C264C265C394C513C512C592
C591
C0402 222P 1 C272
C0402 223P 2 C421C417
C0402 224P 1 C256
C0402 22P 1 C353
C0402 273P 3 C414C556C555
C0402 27P 1 C134
C0402 332P 2 C426C432
C0402 333P 1 C516
C0402 220P 7
32103PC0402
37104PC0402
PX777 part list(136-174MHz)
33102PC0402
C0402 100P 12
Designators
910PC0402
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C0402 33P 2 C126C343
C0402 3P 2 C226C232
C262C258C546C666C311C221
C112C111C127C125C141C233
C177C317C243C314C355C312
C356C358C313C204 CAP C310
C412C622C632C531C534C533
C180C260C532C173C667
C0402 473P 3 C424C431C458
C0402 47P 2 C393C324
C0402 5P 2 C215 C347
C0402 680P 2 C428C433
C0402 683P 1 C543
C0402 6P 1 C352
C0402 82P 1 C395
C0402 8P 3 C211C229C235
0603 容
C0603 10P 5 C163C167C165C169C154
C0603 15P 3 C153C161C164
C0603 20P 1 C152
C0603 22P 3 C168C166R818
C0603 470P 1 C162
C0603 56P 1 C155
C0603 6P 2 C325C344
C0603 104P 1 L333
太阳 诱
C0805 0.1uF 4 E367_1E364E411C541
C0805 1uF 4 E454E319_1C104C143
C0805 2.2uF 4 E435E413E363_1E474
E412E242E326_1E180E311E273
R0402 阻 L121R457R663R364_1R363_2
R235R134R362C251R662
R0402 1.8K 1 R365_1
R413R301R524R113R131R363
R321R314R352
R594R595R269R547R529R528
R391R351R459R809R223
R258R429R434R453R201
R543R184 R333R203R111
R561R101R361_2R820
R0402 10R 4 R458R127R125R354
R541R582R392R172R175R174
R173R170R171R583
R0402 150R 2 R456R362_2
R0402 15K 4 R519R522 15K R478
C0805 4.7uF 6
R0402 0R 10
11
1410K
R0402 100R
150K
C0402 470P 35
9100KR0402
R0402
R0402
10
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R0402 180K 2 R265R263
R0402 18K 2 R414R187
R573R591R593R251R254R411
R666 R312_2R313R667R668
R417R596R393
R0402 1K5 2 R421R124
R0402 1M 2 R664_1R183
R0402 1M8 2 R428R433
R0402 2.2K 1 R261
R0402 2.7K 1 R259
R0402 220K 4 R252 R551R181R512
R0402 220R 6 R389_1R331R348R312R571R244
R0402 20K 3 R544R472R436
R0402 22K 4 R552R415R313_2R515
R0402 22R 2 R112R315
R0402 270k 1 R665
R0402 270R 3 R156R155R358
R0402 27K 3 R556R141R555
R255R452R451R455R202R302
R103R516
R0402 3.3K 3 R367_1R366_1R264
R0402 30K 2 R422R177
R0402 330R 3 R128R811R126
R426R427R431R432R423
33K
R0402 39K 1 R554
R0402 3K3 4 R435R355R359R357
R0402 3K9 1 R123
R0402 470R 1 R572
R0402 470K 1 R553 R518R592R525R527R526
R322R581R132R142R186R182
R597R222 R221R387
R0402 47R 4 R326_1R133R143R247
R272R273 R574R575R576
R243R311R538R262R271L342
L323
R0402 560R 3 R412R368_1 R110
R0402 56K 2 R311_2R517
R0402 5K6 2 R661R356
R0402 680K 1 R416
R0402 680R 1 R114
R0402 68K 2 R542R185
R0402 6K8 1 R424
R0402 82K 2 R521R523
R0603 0R 3 L591L133L331
R1206 阻
4K7 12
82K2R0402
1KR0402
R0402
R0402
633KR0402
14
1547K
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R1206 0.39 3 R104R105R106
L0603 感 L411L511L111L122100NHC697 高频叠层
L326_1L313L315
L0603 101T 1 L521 瓷珠
L0603 1UH 1 L391
L0603 220NH 5 R807L354L351L348L242 高频叠层
L0603 33NH 1 L143 高频叠层
L0603 47nH 1 L352 高频叠层
L0603 560UH 1 L392
L0603 6.8UH 2 L321L341
L611L640L131L141 L227 瓷珠
瓷珠
L1008 R12 4 L325L343L248 L316 绕线
L0805 R22 1 L155 丰华绕线
L1310 1uH 1 L168 太诱绕线
L2520 1R0 2 L246L132 太诱绕线
L0805 68NH 3 L225L229L241 高频叠层
L0805 R15 1 L215 绕线
二极管类
D_ESC B9 4 D322D321D342D341
D_ESC HSC277 4 D212D235D211D111
D_SMA
1SR154-400
1 D611
D_USC 1SV220 1 D323
D_USC MA77 1 D155
D0603 GREEN 1 D571
D0603 RED 1 D573
D-ESC PMSD4148 2 D312_1D311
D-USC 3V 1 R806
D-USM-MA742
MA742 1 D661_1
集成类
SOP8 24C16 1 U561
SOP8 LM4558 1 U411
SOT24 3SK241 2 T241T221
SOT89 2SC4988 1 T121
SRP8 10K 1 PR511
SRP8 1K 2 PR752PR311 1
SSOP10-P-225
TA7368F 1 U451
SSOP16-225TA31136 1 U261
SSOP8 LM2904V 1 U170
U-SSOP20-225
LMX2332 1 U311_1
三极管类
T_ESM 2SC4617 3 T311T421T431
T_ESM 2SJ243 1 T312
T_ESM 2SK1824 1 T541
T_ESM DTA114EE 2 T261T573
T_ESM DTC114EE 3 T451T571T572
L0805
9100NH
5101T
L0603
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