Technical Manual
Table Of Contents
- Vocoder and Controller Boards Detailed Theory of Operation
- Introduction to This Section
- General
- Vocoder Board
- Controller Board
- Switching Regulator
- RX Signal Path
- TX Signal Path
- Controller Bootstrap and Asynchronous Buses
- Vocoder Bootstrap
- SPI Bus Interface
- Universal Connector and Option Selects
- Keypad and Display Module
- Controls and Control Top Flex
- Controller Memory Map
- Vocoder Memory Map
- MCU System Clock
- DSP System Clock
- Radio Power-Up/ Power-Down Sequence
- Notes
- Secure Modules
- Disassembly/Reassembly Procedures
- Troubleshooting Procedures
- Troubleshooting Charts
- Troubleshooting Waveforms
- Troubleshooting Diagrams
10-32
Chart 32. 800 MHz Voltage Controlled Oscillator (VCO)
VCO TX/RX Unlock
MAEPF-24388-O
NO
VDC
U307-9
VDC
U302-19
VDC
U302-20
VDC
U302-17
NO YES
Check Continuity
Between
U302-19 &
U307-9
YES NO NO
YES
5VDC
U307-3
777-825MHz
Change U302
5VDC
U303-6
806-825MHz
VDC
U303-3, 13
NO
YES
YES
NO
5VDC
U307-8
850-870MHz
Measure
Freq.
U303-15
Measure
Freq.
U302-21
Refer to FGU
Chart C.32
VDC
U307-1, 7
Change U307
5VDC
U302-38
806-825MHz
Check Continuity
Between
U302-38 & U303-6
Refer to FGU
Chart C.32
YES
NO
YES
NO NO
YESYESYESYES
NO
Check C310 if
OK Change
U302
Refer to
Chart DC
Switch C.37
Check L301,
C377 if OK
Change U303
NO
NO