Detailed Circuit Theory; Com Receiver; Table 4-1 Component Designators - Honeywell Bendix/King KX 165A Maintenance Manual

BENDIX/KING
4.3

DETAILED CIRCUIT THEORY

The detailed circuit theory description is broken into the following functions:
1. Com receiver/IF board
2. Transmitter
3. Nav (VOR/LOC) receiver
4. Glideslope receiver
5. CPU
6. Power supply
7. Front Panel and Display
8. VOR/LOC Converter I/O Board
These functions may involve more than one assembly; therefore, component designators will
point to the assembly on which the parts are found. For example, R1 is on the glideslope refer-
ence oscillator, and C1001 is found on the main board.
1000
2000
3000
4000
5000
6000
7000
4.3.1

COM RECEIVER

Refer to figure 6-21 for the com receiver schematic. Some receiver audio functions appear on the
main board schematic in
4.3.1.1 Digital/Analog Interface Circuitry
Clock, Data and Enable signals generated by the microprocessor on the Main board are used to
program the following sections of the receiver:
• Synthesizers for the two receivers (U3011 and U3018)
• Two digital to analog converters (DACs) for alignment functions (U3005 and U3006)
• A serial to parallel register for controlling various modes of the receivers (U3002)
• An EEPROM which stores alignment values for the receiver (U3007)
The enable decoder, U3003, determines which of the devices above read the serial data being
sent by the microprocessor. A high on the outputs of U3003 enables that respective device. Se-
lect 1, Select 2, Select 3 and Enable lines from the microprocessor control U3003.
4.3.1.2 Digital to Analog Converters
Rev 0, Jun/2000

Table 4-1 Component Designators

Main
Bezel (front panel)
NAV/COM Receiver
Transmitter
Not used
Audio
VOR/LOC Converter I/O Board
figure 6-8.
15610M00.RCD
KX 165A
Page 4-29