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First Light - update
Hi All,
My 6" coil is producing consistent 29" length streamers
and I solved the problem with the safety gap firing
continuously. Once I hooked up the NST-case ground,
the muffin fan frame, the center terminal of the safety
gap all to a common ground plate connected to the
4" wide out-going RF ground, everything settled down
very nicely. The safety gap only fires occasionaly now,
just like it should. I could hear the coil come into finer
and finer tune as I had many runs and adjustments.
The output of the toroid is extremely loud.
As Mike Hammer reminded me on the Tesla-1 list,
connecting two of the Fair Radio .01 caps in parallel
together gives a total of .02 mfd, which is probably a bit
much for my 15/60 NST to charge up. It does work well
on the tap for turn #11. My original intent was to hook up
both of my 15/60's to get 120ma, so both of the caps
would work much better when I get the NST's connected.
When I tried just one of the Fair Radio .01 mfd caps by
itself, I had to retune at turn #15. Just using one cap
provided a lot more streamers, much longer, probably
closer to the 3 ft range. I personally like the coil
performance with using both caps together. The
streamers aren't as long, but they are much thicker.
With respect to the critics of the Fair Radio Cap -
It performed like a champ and I'm quite pleased with
it's performance. I had at least 30 runs with 3-4 minute
rest intervals between each run on this past Saturday
and the cap is built like a tank. It took several runs on
just one cap by itself to get warm; with two connected up,
they were stone cold. I think this cap has been unfairly
maligned. It seems to work well and is probably the
cheapest off-the-shelf commercial cap you can get,
without getting involved in MMC construction.
I will need to get some power factor correction caps
installed for the NST(s) as while running the coil, it does
pull quite a bit of current from the wallplug. I noticed the
moderately thick extension cord I used (10 ft) did get
noticeably warm.
I am using the RQ static gap, 11 gaps at .030, which
seemed to work well. I used all 11 gaps. I have not tried
experimenting with using less gaps, or varying the gap
widths, but that's next on the list.
My flat primary is dead even with the first turn of the
secondary. While the primary itself is fixed to the table
top, I can remove a standoff underneath the secondary
to lower it, which would put the primary about 1/4-1/2"
above the first turn of the secondary. I was not getting
many hits to the strike rail, but when they did happen
I could hear a loud POP! and a corresponding noise/flash
at the safety gap at the same time.
Some things I noticed - The secondary coil DOES
retain a charge, even after the caps are shorted out
with a wire to discharge them. I would discharge the
caps, ground the toroid, ground the secondary and also
ground my target piece of metal (which also held a
charge). When I ran the grounding wire across the
secondary, I could hear it crackle.
Malcolm has given me some excellent suggestions
on the Tesla-2 list, some of which I'm going to try
this week. I will have to work up to getting some
measuring and testing equipment. I have no
idea where my first-level quenching is situated.
To Bert Pool - Killing just one garage door opener
is enough for me, even with removing the circuit
boards I don't think I'll try risking another unit. :-)
The coil will go outside from now on.
Now that I know the coil works, it's time to finish
it up with putting the RFI filtering and NST protection
systems in place. I believe with a smoother toroid,
finer tuning and some gap adjustments, I should be able
to get more than 3 foot streamers from the coil.
http://www.fwpd-dot-net/dona/tesla/teslacoil.htm