A14 L.o. Synthesizer Troubleshooting - Keysight N8973B Service Manual

L.O. Synthesizer/Reference Troubleshooting

A14 L.O. Synthesizer Troubleshooting

A14 L.O. Synthesizer Troubleshooting

Turn on the analyzer and wait for the instrument to complete the boot up
process. There are (6) processes to perform, which will verify the L.O.
Synthesizer Assembly is functioning properly:
— Press MODE/MEAS, Spectrum Analyzer, OK, FREQ, 50 MHz, Zero Span.
— Press System, Alignments, Align Now, Align Now All. If the alignment
— Measure 4800 MHz Input frequency (from A16 Reference Assembly)
— Measure 4800 MHz Input Power (from A16 Reference Assembly)
— Measure L.O. Output Power.
— Measure L.O. Output Frequency.
These items can be checked with a functioning spectrum analyzer using cables
and connectors that function well up to 10 GHz.
Figure 8-1 A14 L.O. Synthesizer Assembly
272
LED's DS1-DS3 located near the top of the board next to J10 should all be
off. See LED location in
functions correctly with no error messages on the analyzer display, most of
the board is working properly.
Figure 8-1 below.
Keysight NFA Series Noise Figure Analyzers Service Guide