2400 turn sec report

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <FutureT-at-aol-dot-com>

All,

I've pretty much completed the low power testing of the new
2400 turn secondary wound on a 8.3" x 33.5" fiberglas form,
using 28awg magnet wire.  I kept the old 12awg wire primary,
which is tapped now at 38 turns.  Tank C = 0.0133uF.  Power
supply is homemade ballast with 1.5kVA, 14.4kV PT.  The gap
is my new 4 series gap sync gap (120 bps), with remote electrical
phase shifter circuit.  The resonant frequency is somewhere 
around 65kHz or so.  A 12/30 NST would give the same results
of course.

While holding the input power at 580 watts, (646VA if you trust the
ammeter), I obtained 39" max spark length using a 4" x 13" smooth 
toroid.  The old smaller 1700 turn secondary gave 42" sparks.  The 
same small form wound with 660 turns of 20awg gave 38" sparks.
I tried various couplings, and larger toroids to no benefit.  "Cap Watts"
are about 460, based on bang size and bps, for a charging effiency
of 79.2% if the scope and HV probe are correct.  

I am not surprised by the results, because I've noticed in past
work that large secondaries do not work well with small toroids
for low powered work.  Low power and small toroids need to have
small secondaries.  The secondary self C and the toroid behave
as a voltage divider, and limit Ctop.  It is possible that the high
resistance (331 ohms) of this secondary is hurting the results 
too.  The only way to know what's really happening would be
to rewind this large secondary with 1700 turns of thicker wire,
as a comparison.

Nevertheless, I do know from this test that this design gives no 
advantage, and is actually a disadvantage, but is no worse than
the small (6.5" x 24"), 660 turn secondary.

Using higher powers and the 6" x 24" bulk-buy spun toroid, the 
results are intriquing, but I can't easily measure the spark length
due to space limitations.

John Freau