[Amps] Doorknob quality

[Bill Tippett]

PA2KW:

 > I'm looking for on a 300pF/30kV in my 160 mtr amplifier

 >It will be an extra capacitor switched in parallel with the variable plate
capacitor (so within the tuning circuit)
I "cooked" already two of these (different) doorknobs in just a few minutes.

         You'll do better to use 3X 100 pF in parallel or even 6X 50 pF.  I had
a temperature drift problem with a 500 pF 5 kV padder on the 160 output of my
Amp Supply amplifier.  After trying higher voltage doorknobs (both 7.5 kV and
15 kV) I still had the temperature drift problem.  I then made a bracket to
hold 5X 100 pF 5 kV doorknobs and the drift problem was solved.  Another
alternative is a large mica RF capacitor if you can find one and have enough
space in your cabinet.

                                         73,  Bill  W4ZV