Some SB-200 issues

[Kenneth G. Gordon]

On 1 Jul 2009 at 17:42, Robert Groh wrote:
 
> A disk ceramic would work but you will have to careful that you have
> the voltage and the current capability.

Ah! The CURRENT capability....I had forgotten about that! Yes. And 
that is where the heat comes from....

> Some manufacturers will
> provide RF current ratings for their ceramic capacitors.

OK. I'll look for those, but have not, so far, seen any.

> Lacking that
> you could go by material type - I would go only N750 or less and go
> for bigger physical size = NPO types are the best.

Thanks.

> And of course you
> need the voltage breakdown. You could certainly use capacitors in
> series and/or parallel to get where you are going.

I have thought of that, but I am trying to keep things relatively "small".
 
> Aside from those generalities, it turns out that I have 2 caps that
> might be of interest. Both are out of an old homebrew 1KW+ amplifier I
> just tore down to part it out. Both are Cornell Dublier transmitting
> style micas, both are 400 pF and both are rated at 2500 VDC working
> and 5 KV test. One is a type 9H and the other is a type 9LS.

Where does one find the specifications for these various types?

> Both are
> brown plastic case with threaded terminals and are about 1-3/4" x
> 1-1/4". One is about 1/4" thick and the other is twice that.

I think I know the type. We used to call those "postage stamp" types, 
because of their shape.
 
> The capacity checks ok on each but no idea if they still handle the
> voltage (they appear to have been used into the mid 1980's or so). Any
> interest?

Yes. See a private e-mail coming your way...

And THANKS!

Ken Gordon W7EKB

-----------------------------------------------------------
Products bought, sold or traded here is the responsibility of the
parties involved.  This list and the City of Tempe are not responsible
for losses or misrepresentations of any kind.  Buyer beware!

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.aspx?list=HEATH
To post - HEATH at LISTS.TEMPE.GOV
Archives - http://lists.tempe.gov/archives/HEATH.html