Exciter Block Diagram

 

599H-2 - Test Set
    Routes audio from OK-145 to IF Translator circuits for 1KHz CW, VOX and Anti-VOX Inhibit
   
    The difference between the low level and high level self-test is that high level self-test has one more amplifier applied.

652J-4 - Power Supply
    Provides all switched and continuous voltages to all other GRT-17 Slices

    The continuous voltage oscillator section is enabled by 120VAC applied when that circuit breaker is placed in ON position.
   
    The switched voltage oscillator section is enabled by a ground through the 1A31A6 Air Flow Interlock
   
    47-460Hz is the frequency of the two oscillator sections (400Hz secondary oscillator output with 115VAC)
   
    115VAC at 400Hz is NOT monitored by A1U1
   

887B-1 - Frequency Synthesizer (Same as Receiver)
    Produces all frequencies necessary for mixing:
        - 9.9MHz
        - 9.9KHz
        - 250KHz
        - 256.25KHz
        - 243.75KHz
        - Variable injection
       
    9.9KHz Phase-Lock-Loop (ØLL) outputs 107.1500 - 79.1501MHz to RF Translator
   
    10KHz ØLL outputs 93.29 - 64.31MHz to 9.9KHz ØLL
   
    9.9MHz ØLL provides outputs of 9.9MHz to 9.9KHz ØLL, A20 x10 multiplier, 6.29KHz multiplex divider, and a 100KHz reference to the 250KHz ØLL
   
    250KHz ØLL provides 250KHz reference to 6.29KHz multiplex ØLL and 250KHz to 889B-1 for demodulation
   
    6.29KHz multiplex ØLL provides 243.710KHz and 256.29KHz to the 889A-2 for demodulation

888B-1 - IF to RF Translator
    Contains the RF translator (No Preselector) and converts IF to RF
        - Converts 250KHz +/- 6.29KHz to window frequency
   
889A-7 - IF Translator
    Converts Audio to IF (250KHz +/- 6.29KHz


Receiver slices 887B-1 and 652J-4 can be interchanged with the same Transmitter slices.

    - Main Breaker applies power to the rack
    - RCV Breaker applies power to the 652J-4 to turn on continuous voltages (Blower Breaker must also be ON)
    - Enable Receiver at OK-145 Control head
    - When positive air pressure is felt (from the blower) interlock 1A31A6 closes providing ground to Control switched voltages in the 652J-4.
    - Voltages are then routed to individual areas

System will NOT Tune Complete until the PA does.


Created by PA4RM