AR 60S1G6, Operating And Service Manual

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Model 60S1G6
20 Rev C
4.3 TROUBLESHOOTING
CAUTION:
The microwave transistors used in the Model 60S1G6 amplifier are GaAs
FETs. These devices are very reliable when installed in a suitable circuit,
but they can be easily damaged by improper troubleshooting or handling
techniques.
The gate junctions of the GaAs FETs have a high input impedance and
are susceptible to static damage or damage due to the use of an
ungrounded soldering iron. Do not try to check the GaAs FETs with an
ohmmeter.
Use caution when troubleshooting the GaAs FETs; do not short the gate
to the ground or to the drain.
CAUTION:
Use care when unpacking new GaAs FETs. The GaAs FET packaging
should only be opened at Electrostatic Discharge (ESD)-approved
workstations, by individuals who are familiar with the handling of
microwave GaAs FETs and other ESD-sensitive devices.
Troubleshooting the Model 60S1G6 in a logical manner can speed the solution to a problem. The settings of
potentiometers (pots), capacitors (caps), or other variables should not be disturbed until other problems have
been eliminated. Comparing the measured DC voltages to those shown on the schematics can solve many
problems. Before measuring circuit voltages, first verify that the voltages to the circuits are correct.
Model 60S1G6 troubleshooting symptoms and remedies are described in the sections that follow

4.3.1—Power On Indication Doesn’t Display on Front Panel when POWER Switch is Depressed

4.3.2—The Unit Cannot be Operated Remotely

4.3.3—Thermal Fault

4.3.4—Interlock Fault

4.3.5—PS1 Fault

4.3.6—Amplifier Faults

4.3.7—Low or No Power Output (DC Tests)

4.3.8—Low or No Power Output (RF Test)