At 11:12 PM 4/28/97 -0700, you wrote:
>No, but I just might. That is a damned clever idea.
>
>Was your capacitance calculation affected much by the dissimilar size of
>the "plates?" Or was a straightforward calculation accurate enough?
>--
>Garry Shapiro, NI6T
>Editor, "The DXer," newsletter of the NCDXC
>Visit the Northern California DX Club 50th Anniversary page:
>http://www.aa6g.org/ncdxc50.html
>
No, I figured the surface area of the teflon square plus the thicknets and
guessed. I would thing that you could do better calculations that I could.
The chasis acted as the ground side of the cap and seemed to not affect it.
I had calculated for about 500 pf, which if I remembner correctly around a
4" square. I kinda guessed at it all, but I could get the tank to resonate
on 150 throuhgout the whole band with the 200 pf capacitor I was using for
the plate tuning control. The teflon has a breakdownn voltage of 2000 volts
per mil if I remember right. I think the piece I used would have taken
about 10,000 volts. Alot of what I did was by the seat of my pants. Got
the idea from a QST article in the 70s. That is what I remember.
Lee
k0wa@southwind.net
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