Keysight N8976B

Keysight NFA Series Noise Figure Analyzers Service Guide 191
RF Section Troubleshooting (N8973B, 74B, 75B Analyzers)
Troubleshooting
The level should be −28 dBm ± 2 dB as shown in Figure 4-32.
Figure 4-32 4.8 GHz Calibrator Signal on Output of Attenuator B
Press Mech Atten and enter 6 dB. The 4.8 GHz calibrator signal measured on
the functioning Spectrum Analyzer should measure 6 dB lower than the
previous step (~−34 dBm).
Press Mech Atten and enter 10 dB. The 4.8 GHz calibrator signal measured on
the functioning Spectrum Analyzer should measure 10 dB lower than the first
step (~−38 dBm). Continue testing all the attenuation settings as described in
Table 4-18.
Table 4-18
Attenuator Setting Expected Level
dBm @ 4.8 GHz
Tolerance
16 −44 ±3 dB
20 −48 ±3 dB
30 −58 ±3 dB
40 −68 ±4 dB
50 −78 ±4 dB
60 −88 ±4 dB