Model
83522A
POWER HOLES
Service
Check all RF connections in the proper loop(s). Narrow-band power dips
or "holes" are usually the result of loose or faulty RF connections. Tighten
all internal RF connectors. Secure the front-panel RF connection. Inspect
the front-panel RF connector for damage or wear, and clean or replace
parts as necessary. Section
VI,
Replaceable Parts, provides an exploded
view of the RF connector.
Microcircuit Verification By Assembly
The information below is organized by microcircuit assembly in RF signal flow
order. It provides troubleshooting tips to isolate a particular microcircuit failure.
This information is intended as a guide. Any suspected failure should be
thoroughly researched before replacements are made.
The general approach to troubleshooting is:
1. Make sure that all power supply voltages are present. If not, trace the
problem back through the
83522A to the 8350A.
2.
Make sure all bias and control signals are present. If not, trace the problem
back to the supplying assemblies.
3.
Check the RF levels into the suspected microcircuit. If faulty, trace the
problem back through the RF path.
4.
Check the RF levels out of the suspected microcircuit. If faulty, replace the
assembly.
IN EVERY CASE, check power supply voltages. Make sure control signals and
bias voltages are being supplied from the other circuits before replacing any
microcircuit. Refer to the Service Sheet appropriate to the assembly supplying
the control signals for voltage levels and waveforms.
A1
2
YIG OSCILLATOR
Check RF output directly from the YO for about
+14
dBm. For power drop-
outs, check OSC BIAS for -10 Vdc
A1
6
CAVITY OSCILLATOR
The output of this assembly should measure approximately
+9
dBm RF power
at 3.8
GHz.
Ensure that A16 is functioning. Control line MOD 0 should be near 4-0.7 Vdc. If
not, remove the modulation control wire and check for approximately +5 Vdc.
If this is not the case, troubleshoot
A4.
To verify the MODIMIXER, remove the
A4
assembly. Monitor the RF output directly from A17. In this open loop
condition the power should measure approximately -12
dBm. (Expect high
harmonic distortion.)
To Next Page
Loading...
