Thank you rf-loop for the measurements
It seems my analyzer is seriously sick
Observations:
- Generator set to 50 Ohm, 0dBm, 1 MHz sine wave
- If Generator terminated with 50 Ohm load I measure with oscilloscope 656 mVpp => 0.31dBm
- If Generator is loaded with SSA3021X I measure with oscilloscope 500 mVpp => -2dBm (the SSA3021X is not 50 Ohm)
- SSA3021X shows 5.46dBm for the main tone (7.46 dB more compared to what it should be)
- See the attached measurements
Please do some more cross tests just for check.
You can also try next test if you have available good cables and adapters and so on.
THis is not good test but this can do without more things and equipments.
Connect generator out with cable to T (or if you have calibration grade splitter use it). Then other T out to scope using probe/adapter or coaxial.
Connect other T out to cable what go to SSA input. Then you need accurate terminator what you can connect to cable end when you disconnect this cable end from SSA. (for SWR reasons keep all cables same, only swap SSA input with terminator.)
Now look with scope how much level differ if load is SSA input or load is 50 ohm terminator.
This is best to do using some low frequencies, example 1-10MHz.
This is just for keep all things unchanged, (cables lenght and so on so that only part what change is load. In other case load is terminator and other case load is SSA input (SSA powered on!)
Also if possible compare same signal with other spectrum analyzer.
If there is something like 1-6dB difference my suspect is SSA input failure, perhaps first RF switch.