Keysight N8976B

Keysight NFA Series Noise Figure Analyzers Service Guide 159
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)
Troubleshooting
If any of the preselector control currents do not match the levels shown in
Table 4-8, the most probable causes are a misaligned YTF or the A15 Front End
Control Assembly. Perform the YTF characterization (press System,
Alignments, Advanced, Characterize Preselector) and re-check the control
current at various center frequencies.
Table 4-8 YTF Tune Current
Center Frequency
(GHz)
Control Current
(mA)
Tolerance
(mA)
5.0 106 ±20
10
a
215 ±25
15
a
324 ±30
20
a
430 ±40
26
a
560 ±50
a. N8975B/76B
Tolerances should be used as a guideline. The true test is whether or not
the analyzer will function and meet published specification.