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my coil counterpois! oh ya!



Original poster: "J Dow by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jdowphotography-at-hotmail-dot-com>





Hello all

I was asking about using a large metal table (4’-20’) as a counterpoise.
The general consensus was that it would work. I ran the coil with the table 
Friday and it was a major rock’n ark’n spark’n zap’n snap’n deal! My coil 
put out some fine 5-foot streamers, very nice

Coil specs:
Power transformers:
2, 12kv/60ma NST’s banked for 120ma with PFC capacitor to smooth out the 
current draw. On the HV side of the transformers is a serge filter good to 
240ma 15kv to protect the transformers from over voltage (a Terry filter).
Control cabinet:
Two arming switches for mane coil power feed. A “dead-man” switch controls 
power out to the coil through a 15 amp variac. The coil is fused to 15 amp 
with a 15amp fast blow fuse.

My secondary:
It used to be this-
(10.5” cardboard concrete poring form, coil form.
36.5” winding 22awg
2, ¼” lexan disks inside the coil (inner arc prevention) at equal spacing. 
Separating the inside of the coil onto 3 equal segments.
The coil was pre-coated with poly, inside and out and plenty after winding. 
)
This burnt up. The coil form moved around on me causing shorted (overlapped) 
turns.
I’ve made a new secondary. 4” pvc 1/8th wall thickness. 36” tall 35” winding 
half inch space at both ends of the coil. 1750 turns 24 awg.

This coil is SO good; I don’t think I’ll ever make a 10” diameter coil 
again. It does need a Big top load though. :(

Pri: Was a flat 20 turns ¼ cu tube now it’s 12 turns 30-degree platter coil 
for the smaller secondary. This also works like a charm.
Spark gap: SRSG 120BPS It consists of a small 1/25 hp 1800rpm motor that 
spins a Plexiglas disk with 4 electrodes.
Capacitor:
16kv -at- 0.0692uf  “MMC Geek cap”. This is an array of 36 Cornell Dubilier 
capacitors. Each cap is rated for 2000V -at- .15uF there are 4 springs with 9 
capacitors each.

Smaller is better!!!
Halloween is gona be so cool I don’t know what to do

Read you all later
Josh