[Amps] Fw: airspaced C's

[Phil Clements]

Subject: Re: [Amps] Fw: airspaced C's


> **  The main thing is choose a Tune-C with less
breakdown-V than the
> bandswitch - so that during a glitch the Tune-C will
breakdown first and
> protect the more-delicate bandswitch.

A trick Henry uses when the tune C is a vacuum variable, or
a bread-slicer
with a higher breakdown rating than the bandswitch, is to
install a variable C
between the plate block cap. and the tune C; consisting of
two opposing ball bearings
mounted on a suitable insulated fixture.; one with a
threaded shaft running out of it for
adjusting the distance between the balls. One ball hooks to
the anode circuit; the other ball is
@ chassis ground. Sort of looks like an old two-plate
neutralizing cap., except with balls instead
 of plates. Then one uses a hi-pot tester to adjust the
proper spacing of the balls to be a lower
 break-down voltage than any down-line component in the tank
circuit. Then, this little $2.00 gadget
 takes all the hits for you. I am sure Henry would sell you
one if you don't want to roll one
for yourself. They are installed in all of their RF
generators that I have seen.

Season's Greetings to all of you "Amper's" out there from
East Texas!

(((73)))
Phil, K5PC