Re: Capacitor advice

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Gregory Hunter by way of Terry Fritz <teslalist-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>

Hi Phil,

I think you dropped a digit. Looks like .0003uF, not
.003uF. That's only 0.3nF. Hope you have a lot of
them.

Many coilers have used ceramic doorknob caps in Tesla
coils with good results. If they are not suitable for
TC use, this will be revealed pretty shortly after
first light by cap failure. Found that out the hard
way with some Russian doorknob caps that really were
too good of a deal to be true.

Best Regards,

Greg

--- Tesla list <tesla-at-pupman-dot-com> wrote:
 > Original poster: "Phil Parry by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <ryukin-at-ntlworld-dot-com>
 >
 > Hi group,
 >
 > I'm an experienced electronics tech, but now working
 > in IT.  I'm new to
 > coiling, and have been gathering a collection of HV
 > bits to hopefully make
 > some nice toys with.
 >
 > I picked up some very beefy looking Sangamo
 > transmitting capacitors at a
 > radio rally today and I'd like to know if/how
 > suitable they would be for TC
 > use.  I've posted a 20Kb jpeg at
 >
http://www.nottingham.ac.uk/~enzpp/tesla/sangamocaps.jpg
 > .
 > They look like extra large versions of doorknob caps
 > and come with big
 > aluminium plates bolted to the terminals.  I have
 > two values, the smaller is
 > 0.00075uF (750pF) at 6000V and the larger is 0.003uF
 > (3nF) at 20kV(!)  They
 > are both rated at 6.8A current at 1MHz - I would
 > think they were intended
 > for a high power, low frequency ATU.
 >
 > I'd be grateful for info/advice on these - knowing
 > what the dielectric is
 > would be nice for a start.  I gather that ceramic is
 > generally a bad choice
 > for TC capacitors.  I'd hate to ruin them through
 > ignorance.
 >
 > If they're not suitable for a tesla coil, I'm
 > thinking of becoming active on
 > the 136kHz ham radio band - these caps look just the
 > job for antenna
 > tuning...
 >
 > Thanks for listening!
 > Phil
 >
 >


=====
Gregory R. Hunter

http://hot-streamer-dot-com/greg

_