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Final test on new TC



Subject: 
            Final test on new TC
       Date: 
            Sun, 23 Mar 1997 16:17:33 -0800
       From: 
            Skip Greiner <sgreiner-at-wwnet-dot-com>
Organization: 
            Greiner, Ltd.
         To: 
            tesla list <tesla-at-pupman-dot-com>
 References: 
            1 , 2


Hi Everyone

Here are the final specs and test results on my new coil. Since this
coil has a somewhat different aspect ratio than most, I thought you
might be interested
 
 Sec: 17.5" x 24" (D x H), 192 turns #16 ga stranded machine tool wire
 
 Pri: 23" dia. solenoid wound. 6 turns .375" copper tubing spaced .25"
 
 Cap: .014uf
 
 Toroid: 5.5" X 28"
 
 Input: 15kv -at- 60ma, 900va
 
 Gap: sync rotary, 1800rpm, 4 gaps, 1 closure per each 1/2 cycle,
120/sec
 
 Sec Fr with no toroid: 350khz
 
 sec Fr with toroid: 263khz.
 
 k: .19 with sec mounted 4" above top turn of primary
 
 Discharge length: 48" to 56" with occasional jumps to 60"

 Due to the shortness of the secondary, no strike rail is required.The
 cap and tranny are in very close proximity to the primary and they do
 not take any hits from the toroid either. They are nearly at the same
 level as the primary.
 
For the first time I have witnessed what R. Hull refers to as synergy. I
never have been able to get the discharges to emanate from the purposely
placed bump on the toroid. I always seemed to have multiple discharges
which rotated around the toroid but never concentrated at one spot. In
this particular instance I achieved what appeared to be pretty good tune
between the primary turns, cap and toroid size.At this point I started
to decouple the secondary by raising it .75" at a time. Interestingly
with the secondary almost exactly 4" above the primary the discharges
became concentrated at the bump on the toroid. .75" above or below this
point caused the discharges to again split up and rotate around the
toroid. Also at this coupling the primary tuning became very sharp. Plus
or minus one turn reduced the discharges by almost 1/2. Changing the
size of the toroid also reduced the discharge length. *This is synergy.*
Another interesting point: my safety gaps are set to only about .25" yet
they never fire when the coil is tuned as described.

Next step: onward to 1.8kw, 15kv-at-120ma. Who knows, maybe 72" with 1.8kw.
I think that to achieve tuning with a larger primary cap I will have to
rewind the secondary with a smaller diameter wire, or maybe a wire with
thinner insulation.

Skip