Re: Dissapointing and confusing Results with MMC

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

Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>

Hi CJ,

Neat!  We have not had an MMC problem to figure out in a long time :-)

For 9kV at 120mA, I assume you have a static gap and are running LTR for a
46nF cap.

http://hot-streamer-dot-com/temp/MMCcapSales.gif

The buzzing noise, if it is really loud, is "bad".  It may be core
saturation in the NSTs.  But that would mean something is not connected
right.  The secondary base should always be grounded, but I don't know hat
you mean by grounding the "primary"?

The protection circuit will not affect the coil's performance and would not
be a factor for this problem.  Unless... one side of the NST has died.  But
I doubt that.  The resistors do not affect performance either.

"I just hooked up the leads from each cap with folded peices of tin foil"
Now that might be a big problem! =:O  For the coil to fire well, it will
have to pump ~500 amps of RF through the primary circuit.  Folded aluminum
foil connections will have very bad loss if they just don't burn right up.
Solder, bolt, clip, or heavy twist the leads.  The average current may not
big high but the firing pulses are giant and those connections have to take
many hundreds of RF amps!!

So get rid of the folded foil connection stuff and try again.  That should
make it work fine :-))

BTW - If the caps have poor connections, beware that they may still have a
big charge on them!  Short them all out completely before you go working on it!

Cheers,

	Terry



At 11:21 AM 2/9/2002 -0800, you wrote:
>After my other cap died on me (35kv .035 uf) I decided to upgrade to an MMC
>which I built to 18 kv .05 uf tested at .046. My primaries are 2 NST's 9kv
>60ma each. After hooking up the new cap, I had shorter sparks and it
>operates very inconsitently. Maybe 1/5 times it works, 4/5 times it makes
>this buzzing noise and then I turn it off, turn it on, etc. Another thing is
>that when I ground the primary and secondary, the coil doesn't work at all
>and doesn't making the buzzing noise. With the old cap I had about 20 inch
>sparks(measured to ground), and with the new (i'm guessing) about 8-12 inch
>sparks. I should also note that I do not have a terry protection circuit
>installed, nor do I have any real resistors in the MMC (Instead I just
>hooked up the leads from each cap with folded peices of tin foil). Please
>Help
>
>CJ
>