[Amps] Vacuum Variable Cap Rebuild

[Jim]

Probably a seal problem I would guess on a ceramic vac cap.

Max gain systems is the LAST place I would by a cap from. They are very 
proud of them.

Keep and eye on ebay or QTH.com, or here on AMPS for one.


Thanks
73
Jim W7RY

On 4/10/2021 5:47 PM, Paul Christensen wrote:
> Anyone know if it's possible to rebuild a vacuum variable cap?  It would
> require a precision break of the seals, then evacuating the air with a new
> seal.
>
> A cap used on my 160m transmit "T" failed a few months ago.  While
> dismantling the antenna at the season's end, I brought the cap back home and
> purchased a Megger 230425 Hi-Pot test set.  After testing today, the cap
> repeatedly breaks down at 700V, although it's rated for 5KV.
>
> It would be a shame to discard; it's an expensive Jennings ceramic type with
> a range of 25-5000 pF.  Used, they're $1,500 ea. from MaxGain Systems.  I
> only need a range to about 1200 pF, so I can definitely get by with an
> alternate that's on the shelf.  That's not the issue.  I would like to save
> the cap if possible.  I'm not sure what conglomerate owns Jennings now but I
> doubt they would have a rebuild service when it's much more profitable to
> sell new caps.
>
> Paul, W9AC
>
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