Keysight NFA Series Noise Figure Analyzers Service Guide         223
RF Section Troubleshooting (N8976B)
Troubleshooting
Attenuation Check
Set the signal source connected to the analyzer input port to 0 dBm. On the 
analyzer, press Amplitude, Attenuation, Mech Atten and change input 
attenuation to 0 dB. The measuring spectrum analyzer connected to A10 
Attenuator output port should indicate a 0 dBm level. Change the input 
attenuation on the analyzer under test to 2 dB. 
See the chart below for expected measurement values at the A10 Attenuator 
output port. 
Analyzer Under Test 
Attenuator Setting (dB)
Power at A10 Output 
Port (dBm)
Input Attenuator Being 
Tested
0 0 dBm (reference) Both set to through path
2 −2A9
4 −4A9
6 −6 A9
8 −8A9
10 −10 A10
20 −20 A10
30 −30 A10
40 −40 A10
50 −50 A10
60 −60 A10