TM 11-5820-921-40-1
3-113. If components of the HV overload circuit, on DC Control PWB Assembly 1A2, are replaced, the
following HV OVERLOAD THRESHOLD ADJUSTMENT should be performed* (refer to figures 3-66 and
3-78).
Establish the adjustment setup shown in figure 3-24.
1.
2.
Adjust HV OVERLOAD THRESHOLD potentiometer 1A2R20 fully clockwise.
3.
Close T/R LINE toggle switch applying a ground to 1A2P1-12.
4.
HV ON indicator connected to 1A2P1-21 should illuminate (GRN).
5.
Adjust potentiometer 1A2R20 counterclockwise (CCW) until OVERLOAD FAULT indicator
1A2DS1, on PWB, and OVERLOAD FAULT indicator connected to 1A2P1-11 illuminate (RED).
HV ON indicator connected to 1A2P1-21 should extinguish.
6.
7.
Close the TUNE START toggle switch applying a ground to 1A2P1-6.
8.
Both OVERLOAD FAULT indicators should extinguish and the HV ON indicator should illuminate.
9.
Open the TUNE START toggle switch, removing the ground from 1A2P1-6.
10.
Both OVERLOAD FAULT indicators should re-illuminate and the HV ON indicator should
extinguish.
3-115. If components of the +26.5 Vdc overvoltage circuit, on System Control PWB Assembly 1A3, are
replaced, the following procedure should be performed (refer to figures 3-67 and 3-78).
1.
Establish the adjustment setup shown in figure 3-25.
2.
Close the PA ON toggle switch, applying a ground to 1A3P1-2.
3.
Adjust OVER VOLTAGE potentiometer 1A3R3 fully counterclockwise.
4.
Adjust variable power supply input at 1A3P1-3 to +33 Vdc 1 Vdc.
5.
Adjust OVER VOLTAGE potentiometer 1A3R3 clockwise until the PA ON indicator connected
to 1A3P1-4 illuminates.
6.
Adjust the variable power supply input at 1A3P1-3 to +26.5 Vdc; then continue adjusting toward
+33 Vdc. The PA ON indicator connected to 1A3P1-4 should extinguish at +32 Vdc 1 Vdc.
1A13A1R9 are replaced, the following procedure should be performed, (refer to figures 3-71 and 3-77).
Establish the adjustment setup shown in figure 3-26.
1.
2.
Set the power supply for +26.5 Vdc (nominal).
3.
Turn on the receiver-transmitter volume control and select 7.000 MHz, CW Mode. Observe that the
power amplifier RDY (ready) lamp 1Al4A4DS1 illuminates after approximately one minute.
4. Apply a CW key signal. Observe that the power amplifier tunes then stops (see TUN lamp
1A14A4DS3 on front panel).
5. Ground test point 1A7A2TP2 on the ALC Module Assembly 1A7.
6. Apply a CW key signal, Adjust Ip ALC potentiometer 1A7A2R1 for a reading of 45 amperes on the
Simpson meter.
7. Remove the ground from test point 1A7A2TP2.
*For optimum performance, DC Control PWB Assembly 1A2 should be aligned in the PA in which it is
intended to operate. However this procedure will align the PWB close enough for acceptable operation.
