Keysight N5224A/25A Service Guide 4-39
Troubleshooting
Measurement System Troubleshooting
Checking the A7, A8, A12, and A13 50 GHz Doubler Outputs
1.
Refer to the block diagram at the end of this chapter and to
Assemblies and Cables, All Options” on page 6-16
. Locate cable W11 on
the A7 doubler board, cable W17 on the A8 doubler board, cable W13 on
the A12 doubler board, and cable W15 on the A13 doubler board. (A12 and
A13 are only available in 4-port models and 2-port models with Option
224.)
2.
Disconnect cable W11 or W17 or W13 or W15, dependent on which
doubler board is to be checked.
3.
Connect the spectrum analyzer to the open connector on the doubler
board to be checked.
4.
Set the network analyzer for an 800 MHz CW frequency and observe the
spectrum analyzer measurement. An 800 MHz signal should be present.
5.
. If the observed problem was frequency
banded rather than broadband related, set the analyzer frequency to the
center of the problem band. The spectrum analyzer should measure a
signal above the network analyzer setting. For analyzers with DSP version
4.0, the signal is 7.61 MHz above the network analyzer setting. For
analyzers with DSP version 5.0, the signal is 7.44 MHz above the network
analyzer setting.
6.
If the signal is not present but the signals from
are present, replace the appropriate doubler
“Removing and Replacing the A4–A17 Boards” on
.
7.
If the signal is present, reconnect all cables, and then continue with
“Checking the Signal Separation Group” on page 4-39
.
Checking the Signal Separation Group
Before checking the signal separation group assemblies, you must open the
analyzer.
1.
Turn off the analyzer power.
2.
Unplug the power to the analyzer and disconnect all front and rear panel
connections except installed jumpers.
Use an antistatic work surface and wrist strap to reduce the chance of
electrostatic discharge for all of the procedures in this chapter.
