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[Fwd: First Coil - No Sparks]
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From: Richard Staron [SMTP:rstaron-at-aracnet-dot-net]
Sent: Thursday, June 11, 1998 6:24 AM
To: Tesla List
Subject: [Fwd: First Coil - No Sparks]
Tesla List wrote:
>
> ----------
> From: djQuecke [SMTP:djQuecke-at-worldnet.att-dot-net]
> Sent: Monday, June 08, 1998 8:07 PM
> To: Tesla List
> Subject: First Coil - No Sparks
>
> I just completed my first coil yesterday but I'm not getting any discharge.
>
> 4.3" x 21.625" secondary - 22awg - 10 coats laq before winding then 15 more
> coats. Ground via 10' flat braided cable to 10' of #4 stranded to 8' ground
> rod.
> Started with slight overcouple. Moved incrementally up to 1/4" above first
> primary turn (no affect).
>
> 19"x4" toroid - Foil tape over foil over dryer duct and pizza pans. Tried
> 4" - 8" above final turn on secondary.
>
> 1/4" copper tube primary, spaced 1/4" 15 turns total - tried tap at several
> spot on turns 14 and 15. 15 degree rise. Just over an inch between first
> turn and secondary.
>
> 15kv 30ma NST
>
> NST protection -
> A 500ohm/65w resistor from each NST lead
> 1000pf ceramic caps across resistors
> 3.5mh coil on each leg (one coil showed "minor" shorting so I removed
> both from circuit without affect)
>
> Safety gap - across NST (actually more like two gaps, one from each leg to
> ground)
> I set gaps so they just barely didn't fire with NST alone. During runs, gap
> would go off almost non-stop, I adjusted so that it didn't go off, no change
> on output, readjusted so it goes off intermittently (once every 2 or 3
> seconds)
>
> Main gap - RQ static 6"x9x2" (8 gaps total) tested at 7 gaps in use)
>
> Caps - 4 Oil filled poly each rated around 5300pf, 7500v, wired 2 pair in
> series then the 2 pair are paralleled. Value tested at 5240pf on a decent
> LC digital meter.
>
> Power controlled by 10a variac.
>
> There appears to be a great voltage increase if intensity of safety gap
> discharge is a correct indicator. Main spark gap is firing and appears to
> be doing what I expected.
>
> All settings have resulted in zero output. I had hope to be ballpark close
> and adjust from there but apparently, I'm not even on the field yet.
>
> Thoughts?
>
> Thanks,
>
> dj
Hi DJ,
the coil that you have built is almost identical to the one that I
built, however, the voltage rating of the cap is too low. You only have
15000 volt total across your cap and my feeling is that you have already
damaged them. Recommendation to you is to get a cap rated over
45KV at .005 ufd and the try the system.
The other point that I noticed is that you toroid is much to high above
your secondary. I noticed a great improvement in my coil when I had the
lowest point of the toroid about an inch above the secondary.
--
Regards
Richard Staron, VE3FAC
http://www.aracnet-dot-net/~rstaron