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Re: Help please - info on big CDE pulse caps?

Original poster: "Jim Lux" <jimlux@xxxxxxxxxxxxx>

> > > > The caps themselves are a reasonable 9" wide by 12" deep by 25" tall, > > with a single 16" tall by 5" diameter insulator on top of that. Kinda > > heavy. Connection is via the terminal on top of the insulator and by the > > case of the caps themselves (mounting flanges on the bottom and "ears" on > > the sides of the case). > > Ink on the sides reads: > > "CORNELL DUBILIER ELECTRONICS > > TKB 165 > > .15 MFD 120KVDC > > 50[degree]C MAX OPERATING > > SERIAL NO. 109 > > MANUFACTURED FOR RCA SERVICE COMPANY > > CAMDEN, NEW JERSEY, PER CEMCO > > SPECIFICATION NUMBER 3079B > > MODIFIED PER G-41839002-J31 DATED 17 JUL 1964" > > > > If the ".15MFD" means .15 micro-Farads, then they are kinda big for > > their energy storage.Perhaps the high voltage rating explains this > > disproportionate case size and insulator height. > > Yes, the 120 kV voltage rating is quite high and explains the > relatively large volume vs uFd rating. Also, considering their > date on manufacture, they are certainly not that big for their > energy rating. > > They are definitely > > oil-filled, and I am told by someone who dissected one that they have an > > internal voltage-distribution network of resistors. One has been a tad > > leaky at the base of the insulator, but the leak is very thick and > sticky - > > like molasses. > > Oooh, that sounds a lot like a PCB based dielectric, especially consi- > dering that they were manufactured well before 1977. I'd try not to > get any of that "molasses" on me :^O

Or, just old gummy oil..

These sound like DC filter capacitors (especially with the comment about
internal resistors). Perhaps for a transmitting or X-ray tube?  (After all,
RCA did make lots of high power microwave transmitters at one time).

50-100 kV wouldn't be an unusual voltage for a big klystron, for instance.
Or for a stage capacitor in a Cockroft Walton supply for a particle
accelerator.  Lots of those being built back in the 50s and 60s

Also, don't neglect the possibility that it's a one of a kind for some
special purpose.  Say you're a researcher who needs a 100 kV DC power
supply. You're not going to roll your own caps (literally).  Nope, you call
up a company who does HV work and have them make you a custom.  Not everyone
scrounges HV gear from ebay or surplus places. We just bought a very nice
1kV, 10 Amp power supply at work for running an experimental 5 kW solid
state transmitter.  As I recall, it was in the usual $1/watt range.