12kV, 30ma TC (42" sparks),sync-gap vs. static gaps (fwd)

---------- Forwarded message ----------
Date: Thu, 30 Jul 1998 19:17:16 EDT
From: FutureT-at-aol-dot-com
To: tesla-at-pupman-dot-com
Subject: 12kV, 30ma TC (42" sparks),sync-gap vs. static gaps


A few folks had asked some time ago, if this coil could give the
same performance using a good static gap system as with the
sync-gap.  I had done some tests in the past which gave less
performance using the static gap, (I think the static gaps gave 31"
or so in those tests?)  

Anyhow, I installed the new 24 gap static gap onto the coil,
in place of the sync-rotary, and obtained 34" to 35" sparks max.,
using 23 gaps, (sometimes the gaps fail to fire using 24 gaps, but
when they do fire, the sparks are not noticeably longer).

In a re-test of the sync gap set up, I easily obtained 40" sparks,
I didn't bother peaking the performance to get 42" sparks, but I
know from past tests that 42" sparks are possible. 

Specifications below:

  toroid....4" x 17"  aluminum dryer duct
  sec......4.25" x 23" , #28 formvar magnet wire.
  pri.......19 turns of # 12 stranded pvc ins. wire close wound, flattish 
  inverted cone, 15% angle.
  hook-up wire....# 12
  cap...   .007uF polypropylene, Maxwell brand, polypropylene.
  sync-gap....  Gives 120 breaks per second. 
  ---- or static gaps.... 1/2" by 2" copper pipes glued to a wooden 
  board, spaced 8.5mils, 23 of 24 used. 
  transformer....neon sign, 12kV, 30ma, Jefferson Magnetek brand

Conclusion:  This static gap does not seem to be able to equal the
performance of the sync-gap in this NST powered TC.  I think the
static gap fires at too low a voltage to give optimal performance, but
if the total gap is made wider, they fail to fire.  However, 35" sparks
from this NST with static gaps is still a good output.
  John Freau