capacitor info.

Hi all,

Today, I bought a bargain box of "500 pF, 20 KVDC" capacitors.  They are
apparently made by a firm called "CRL".  They look like a doorknob cap with
threaded ends.  Part number appears to be "TV-20" (all quotes are read from
the cap).  Can anyone confirm my doorknob suspicion?  Anyone use these for
Tesla coil caps?  Please relate any success/ failure stories using these
units as well as any other info.

Thanks, in advance.

John Bowers