You mentioned that the frequency was in error by 200 kHz; that is a big error.
I suggest the first thing to check is the frequency of the internal reference. Hook a counter to the reference out socket on the back of the generator.
If it is not exactly 10 MHz, see if you can adjust it- see manual. If not, start your repair work there.
I have known the 8657 (similar to 8656 but with a frequency doubler to extend upper frequency) to have problems with the reference being outside adjustment tolerance.
This can lead to synthesisers failing to lock at some frequencies and generally strange behaviour.
These are useful generators, reasonable phase noise for a low price.
Hope this helps.
Regards,
Alwyn
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Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.
SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
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