[Test-Equipment] Tektronix Service Locations?

[John Miles]

That's actually a common issue with those.  Things that you can check
yourself:

- ESR of all electrolytic capacitors in the power supply (especially the
ones in the 300V doubler supply)

- Lead dress of ribbon cables going to the CRT deflection plates.  These
must *not* be run alongside the deflection amp board.

- High-value carbon-composition resistors on the deflection amp board.
About 50% of these have drifted far above their original tolerance and are
likely to have become noisy.  They need to be replaced, if only as a
preventative measure.

492 video displays are rarely rock-solid.  The deflection amps were were not
examples of Tek's best work, and they underwent quite a few revisions
throughout the life of the series.  But these three "fixes" will render most
of them very usable.  Only the first one is sort of a pain; you'll have to
remove and disassemble the whole power supply to check the caps.  Maybe save
that for last... and don't forget to renew the heat-sink grease on the power
transistors when/if you do take it apart.

-- john, KE5FX

>
> I have become the owner of a 492 Spectrum Analyzer with an
> unstable  display.
> I figured that I might have to locate a repair facility if I
> can't find  the
> trouble in reasonable time.
>
> Starting at my Pittsburgh, Pa. location is there anything
> reasonably close
> to me that I could deal with? It is a bit heavy and can see a
> hefty shipping
> bill alone just to get it there.
>
> Thanks,
>
> Bob AB3L
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