R&S FSA - Issues with level glitches of 2nd LO

[induzer]

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 

[induzer]

Hi,

so I got the problems solved by doing a full alignment of the 2nd LO Module.

[loulou31]

Hi

I bought a FSAS spectrum analyser and I would like to know how to have access to the service manual to this instrument.
It was in paper form, but I dont know if some has done some scan of it and could be available on CDROM or transfer file, even not free.
Thank you and best regards

Jean-Louis

[loulou31]

Hi,

I have found service manual of FSA ( not FSAS that includes tracking generator) on KO4BB site that it is very rich in manuals :
http://www.ko4bb.com/getsimple/index.php?id=manuals


Jean-Louis