[Test-Equipment] textronix 2710 analyzer problem

[John Miles]

I'd probably check the YIG and its driver circuit first, beginning with the
associated power supplies.  Do you have an output jack where you can observe
the 1st LO's output frequency?

-- jm

> Hi All,
>
> Thanks to this list i could find a xtal to repair my Textronix
> 2710 spectrum analyzer.
>
> Now it works normaly except i small intermittent problem :
>
> I have a lot of parasitics signals equaly spaced. The spectrum is
> very wide, almost all the spam of the instrument and unstable in
> frequency, it shifts up and down.
>
> They are not coming from the RF input, amplitude does not vary
> with input level nor with SPAN.
>
> Only the SWEEP rate is making a change in the spacing on the display.
> at 2ms sweep rate i have approximatively 1 spike every 5 divisions
> at 5 ms approx every 2
> at 10 ms approx every 1
>
> It does not occur each time i start the instrument, but once it
> started it does not seem to stop. It can restart at next power ON
> or not....
> It does not seem to affect the measures.
>
> Has anyone an idea of what this can be ? It looks like a 100 Hz
> parasitic oscillation, but where ??
>
> Thanks for any idea. Patrick on Corsica.
>
>