Re: Capacitor advice

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

Original poster: "Bert Hickman by way of Terry Fritz <teslalist-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Hi Phil,

Nice Catch - those are mica composite transmitting capacitors. While not as 
robust as ruby mica transmitting caps, they are still very tough and will 
operate very well in RF CW circuits including VTTC's, and ham applications 
as long as you stay within their maximum current ratings.

Best regards,

-- Bert --
-- 
-------------------------------------------------
Out-of-Print Physics and Engineering Books and
coins shrunk by ultrastrong electromagnetic fields!
Stoneridge Engineering: http://www.teslamania-dot-com
-------------------------------------------------


Tesla list 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
>
>.