Dave, was the original a doorknob? Like this?
https://www.rfparts.com/580075-7p.html
Some manufacturers have taken towards, as padding on the loading side of the
tank, super quality glass high current surface mount caps in which case it
would look like a silvery rectangle.
Tim N3QE
> On Dec 28, 2018, at 4:16 PM, <daraymond@iowatelecom.net>
> <daraymond@iowatelecom.net> wrote:
>
> Greetings topbanders. . .
>
> While CQing early this morning I began noticing a faint but troubling smell
> in the shack. It smelled like over heated wiring or electrical components.
> It continued to get stronger as I realized the odor was coming from the Alpha
> 99 amp. Indeed, a few moments later it tripped out. I dug into it this
> afternoon and discovered a leaky 75 pF/6 kV cap which is one of five such
> caps in a parallel bank that is pulled in on the band switch to achieve tank
> resonance only on 160m. I have removed the bad cap making the amp
> operational once again with the air variable tuning cap making up the lost C
> (and there’s still a little C to spare on the air-variable). After some
> searching I cannot find a 75 pF/6 kV cap. Mouser does not have anything even
> close in terms of the high voltage rating (hopefully I didn’t something).
> The closet thing Newark has is 47 pF which I have ordered. I’m guessing the
> 47 pF is probably OK but how important is equal current distribution across
> the five caps? Maybe I don’t need to be concerned about it? If I really do
> need the correct 75 pF/6 kV cap does anyone have ideas of a source?
> Replying privately is fine. See you all in the Stew. 73. . .Dave,
> W0FLS
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