Keysight Technologies N5224/5A Service Manual page 112

Troubleshooting
Measurement System Troubleshooting
Figure 4-9 Comparison of Legacy HMA26.5 (5087-7765) and New HMA26.5
(N5240-60101)
Checking the A26 Splitter Output
IMPORTANT! Some PNAs have installed a legacy HMA26.5 (5087-7765)
that is used with a discrete A26 splitter. Some PNAs have installed a new
HMA26.5 (N5240-60101) with an integrated splitter. To identify which
HMA26.5 is installed in your PNA, refer to
1. Refer to the block diagram at the end of this chapter and to
2. Disconnect W53 and W54, one at a time, from the A26 splitter.
3. Connect the spectrum analyzer to the open connector.
4. Refer to
5. If the observed problem was frequency banded rather than broadband
6. If the signal is not present but the signal from
4-36
Cables, Standard 4-Port Configuration, Option 400" on page
the semi-rigid cables W53 and W54, at the A26 splitter.
the NOTE notice on page
800 MHz CW frequency and observe the spectrum analyzer measurement.
For analyzers with DSP version 4.0, an 807.61 MHz signal should be
present. For analyzers with DSP version 5.0, an 807.44 MHz signal should
be present.
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.
Output," is present, replace the A26 splitter. Refer to
Replacing the A26 Splitter" on page
Figure 4-9 on page
4-26. Set the network analyzer for an
"Checking the A25 HMA26.5
"Removing and
7-37.
Keysight N5224A/25A Service Guide
4-36.
"Bottom RF
6-58. Locate