[TMC] Feed thru cap

[John Poulton]

Chris,

If you look the part up in the PAL-500 parts list, you'll find the P/N
CK70AW202M.  This is not a TMC part number, but is the part number for a
2nf Erie CK70-style feed-thru capacitor.  They are, needless to say, no
longer available.  Surplus Sales has some CK70's of higher capacitance
available, but they're obscenely expensive.

A bit of further searching will lead you to a company called Tusonix that
still makes similar parts.  For example, there's:

https://www.digikey.com/en/products/detail/tusonix-a-subsidiary-of-cts-electronic-components/2499-003-X5W0-502PLF/3116039?utm_adgroup=Feed%20Through%20Capacitors&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Filters_NEW&utm_term=&utm_content=Feed%20Through%20Capacitors&gclid=CjwKCAjw9aiIBhA1EiwAJ_GTSqXeFZyhoMnKG4XSLhhDIDxGet3owRB-_5MDTq8KrWO_CDOMdvLkChoCBQMQAvD_BwE

from Digikey.  It's a 5nF 500V unit, but physically very similar to the 2nF
Erie capacitor, and in most instances in the PAL amps, the capacitance
isn't critical.  Downside.. those 5nF ones are over $22..  :*(  But, they
are available, and they're more or less correct replacements physicallly.

There's this capacitor:

https://mgs4u.com/product/feedthrough-capacitors/?gclid=CjwKCAjw9aiIBhA1EiwAJ_GTSm9tWD_xDrlwF3DRqeDdlHazRYqojROcn5buOzpqG9A19rvzrlfDExoCnF8QAvD_BwE

at MaxGain Systems, for a mere 99c each!  It's 5nF @ 1KV feedthru, but is
significantly smaller than the CK70's.  You might be able to fashion a
little bushing to get it to work in the original hole.

I have to say, I've never seen one of these capacitors fail in a
PAL-350/500 amp, but there's always a first time!  If you only need one,
your best bet is likely to be the parts drawers of folks on this list.  Let
us know!

Good hunting and 73, John K4OZY


On Wed, Aug 4, 2021 at 11:01 AM Chris Bolkan <bolkyboats at gmail.com> wrote:

> Hi all!
> I am looking for a 2000pf feed-through capacitor. These things are
> used like popcorn on the PAL 350 and 500, so I assume on most TMC
> equipment. Does anyone have one to spare? I'd like to keep things
> original looking so want to try here before I start researching
> current options from Digikey and the like.
> Many thanks!
> Chris
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