SOUTHERN AVIONICS COMPANY
Model SA100 Dual5-2 Maintenance
5.1.3 Tone Key PWB
1. Attach an oscilloscope to TP1 and adjust R2 and R10 for a sine wave between 5 and 10 volts
peak-to-peak.
2. Attach a frequency counter to TP1 and adjust R2 for 1020 Hz.
3. Attach the oscilloscope and adjust R10 for a 8 volt peak-to-peak sine wave signal. Recheck
the frequency and fine tune R2 if necessary.
4. See figure "Tone Key PWB Diagram." Place jumpers for 400 Hz operation and repeat the
above procedure at TP2 adjusting R3 and R23 for a 400 Hz 8 volt peak-to-peak signal.
5. Remove the jumper or solder in place for the selected tone.
5.1.4 Keyer
1. Connect a frequency counter to TP5 on the Coder Shift Register PWB and adjust R5 on the
Keyer Code PWB for 8 Hz.
2. Program the identifier using the DIP switches on the Coder Shift Register PWB.
5.1.5 Filters
Check that all jumpers are in the correct position for the selected frequency. See Figure “,” on
page 2-34 and Figure “Filter PWB Jumper Detail,” on page 2-35.
5.1.6 RF Section Check
1. Set PA Select to 1.
2. Check that RF LEVEL and MOD are fully CCW.
3. Connect 50 Ohm dummy load.
4. Switch RF to ON. PA voltage should read 0. Check all PA positions. Switch PA READ to
current. All PA positions should read less than 0.3A.
5. Set MONITOR to DSBL. LED above switch should be ON.
6. Set MODE switch to CARR.
7. Switch PA READ to VOLTAGE and adjust RF LEVEL for a reading of 20V. Check all PA's.
8. Switch PA READ to CURRENT and check all PA's. Current should be approximately 0.5A.
9. Connect oscilloscope to the Dummy Load.
10. Adjust RF LEVEL for rated power using the oscilloscope voltage on the dummy load. PA
Voltage should not exceed 90V for all PA's. The PA voltages should be within ±10V of the
Factory Acceptance Test average.
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