Hytera MD78X Service Manual

UHF5 (806MHz
–
941MHz)
Contents
i
Contents
1. Product Controls .................................................................................................................................. 1
2. Disassembly and Reassembly ............................................................................................................ 3
2.1 Disassembling the Radio .................................................................................................................. 3
2.2 Reassembling the Radio .................................................................................................................. 4
3. Exploded View and Packing Guide .................................................................................................... 5
3.1 Exploded View .................................................................................................................................. 5
3.2 Packing Guide .................................................................................................................................. 7
4. Specifications and Blind Spot ............................................................................................................ 8
4.1 Specifications .................................................................................................................................... 8
4.2 Blind Spot ....................................................................................................................................... 11
5. Circuit Description ............................................................................................................................. 12
5.1 Front Panel ..................................................................................................................................... 12
5.2 Baseband ........................................................................................................................................ 14
5.2.1 Power Supply Module .......................................................................................................... 14
5.2.2 Control Module ..................................................................................................................... 15
5.2.3 Audio Module ........................................................................................................................ 22
5.3 RF Section ...................................................................................................................................... 23
5.3.1 Transmitter Circuit ................................................................................................................ 23
5.3.2 Receiver Circuit .................................................................................................................... 25
5.3.3 FGU Circuit ........................................................................................................................... 26
5.4 GPS Circuit Section ........................................................................................................................ 28
6. Troubleshooting Flow Chart ............................................................................................................. 29
6.1 Control Circuit ................................................................................................................................. 29
6.2 GPS Circuit ..................................................................................................................................... 30
6.3 TX Circuit ........................................................................................................................................ 31
6.4 RX Circuit ........................................................................................................................................ 32
6.5 Frequency Generation Unit (FGU) ................................................................................................. 33
7. Interface Definition ............................................................................................................................. 35
7.1 10-Pin Connector ............................................................................................................................ 35
7.2 DB26 Accessory Interface .............................................................................................................. 37
7.3 Other Interfaces .............................................................................................................................. 41
8. Tuning Description ............................................................................................................................. 48
8.1 Required Test Instruments ............................................................................................................. 48
8.2 Tuning Procedures ......................................................................................................................... 48
8.2.1 Tuning the Radio .................................................................................................................. 48
8.2.2 Testing the Radio .................................................................................................................. 51
9. PCB View ............................................................................................................................................. 53

Hytera MD78X Specifications

General

Brand	Hytera
Model	MD78X
Category	Radio
Language	English