Hey forum,
i recently got a boat anchor called FSA Spectrum analyzer by Rohde & Schwarz.
I bought it with the both analyzer bus cables missing, successfully built the harness myself and was happy to have got a probably fully working unit.
Now some weeks later I get constant error messages regarding level error of the 2nd local oscillator.
I want to check the single module without the whole unit on the desk but I have no idea where to start checking the circuitry.
The signal STL2LO on Sheet 2, section F7, is staggering around by times. Some times is about 120-140mV, the next moment its around 300mV. A lever lower than approx. 160mV triggers internal fault messages.
May I start to check the circuitry in the proximity of N2 / V43 on sheet 2 ? Seems to me like the feedback of the output amp.
X4 on sheet 1 is the 200MHz reference input
X7 on sheet 2 is the 2.2GHz / 18dBm LO-output
hack on,
induzer
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