[Amps] Doorknob Caps

[Bob Maser]

I have a pair of yellow "door knob" caps that are marked HI-Q HPA 55 N7 50
500PF 10%. They measure 2-3/8" diameter x 5/8" tall and have a  1/4 x20
threaded hole on both sides.  They look like they could be really husky
caps.  I need to know how many volts these things are rated for.  I plan on
putting 2 in series to use on a Butternut HF2V.  The one that is supplied
with the antenna is 200pf @ 10KV and I need more..... I have seen similar
looking doorknobs used in the Emtron amp. for blocking caps.

Bob  W6TR