AR 10046494, Operating And Service Manual, Page: 51 / 60

Model 60/40S1G18B
Rev A 31
4.3.13 High Band Low or No Power Output (DC Tests) (Schematic
10046186)
All indicators on the Model 60/40S1G18B are normal, the front panel vacuum fluorescent display (VFD)
reads
Power On
, and the cooling fan B1 is operating.
1. Check the position of the RF Gain control—is it set to maximum gain?
2. Check the RF input to the unit—is it the correct amplitude and frequency?
3. Check the RF output connection from the unit—is it correctly connected to the load?
Is the coaxial cable okay?
4. Check the following voltages on the A7 Regulator Board (10044489). If any of the voltages are out of
tolerance, correct them before further troubleshooting.
P20 Pin 13
+10 V
±
0.5 V
P20 Pin 16 -12V
±
0.5 V
P20 Pin 1 +24 V ± 0.5 V
5. Check the voltage on the feed thru caps of the A1A2 Driver Amp. Troubleshoot any incorrect voltage.
C3, C4
-5 V
±
0.5 V
C1 +26.3
±
0.2 V
6. Check the voltage on the feed thru caps of the A1A1 Pre-Amp, with the RF gain control at maximum
gain. Troubleshoot any incorrect voltages.
C2
+12 V ± 0.5 V
C3 -12 V
±
0.5 V
C4, C5 -5V ± 0.5 V
C6 +10 V
±
0.5 V
7. Check the voltage on the feed thru caps of the A4 and A5 20-watt module. Troubleshoot any incorrect
voltages.
C1-C3
+26.3 V ± 0.2 V
C6, C7 -5 V
±
0.5 V