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1st notch qnch--update

Subject: 
        1st notch qnch--update
  Date: 
        Mon, 14 Apr 1997 22:05:30 -0400 (EDT)
  From: 
        FutureT-at-aol-dot-com
    To: 
        tesla-at-pupman-dot-com


All,

In todays tests, I first tightened the coupling, then went back and
re-checked the quench at lower power.

At k = .11, I had been obtaining 1st notch quench at 2640VA.  Tightening
to
about k = .13, still obtained 1st notch quench.  Tightened further to
about k
= .16, but the quench moved to the second notch, and racing sparks
destroyed
the secondary by burning through in two places.  Small incremental
changes in
sec. height were unable to bring about 1st notch quenching at these
tighter
couplings.  Quality of quench seems extremely dependent on tightness of
k
value, magic k values seem to provide a small benefit in quenching. 
Good
tuning is is a prerequisite for good quenching.  By changing the tune
point
by one turn, the quench moved from the 1st notch to the 2nd notch and
stayed
there when a streamer hit a ground.  With proper tune point, quench
moves to
the 2nd notch only when spark hits a ground.

Next I patched up the secondary and changed the system back to 360VA to
see
if the recent sync-gap modification would improve the quench at low
power.
 Originally, the electrodes were less than 1/8" in dia, now they are
over
1/8" in dia.  The quench has now improved from the 2nd notch to the 1st
notch.  In addition, the gap originally had 12 series gaps, now it has
8, but
the benefit of the wider electrodes has overwhelmed this change.  Wider
electrodes for better cooling and quenching were recommended by Dr.
Resonance,  by Bert H. and probably others.  I do not know if using even
wider electrodes would improve the quench at these power levels, it
seems
there would be a point of diminishing returns.  Free ringdown time is
now
about 120uS due to the higher frequency which results from this smaller
(4" x
17") toroid.  Basically, I did not see any change in spark length (still
37"
to 39") for 1st notch versus 2nd notch quenching.  I think this is
because
even when the gap quenched on the 2nd notch, very very little energy was
left
in the second energy packet, so it just didn't make much difference.  I
lowered the secondary to 5/8" above the primary (about k = .16), still
quenched (mostly) on 1st notch, and another streamer started to form. 
My
next test will be to tighten the coupling even more, and see what
happens.

After that, I may go to a non-sync system to compare small-cap, high
break-rate operation with my previous (above) results.  I will be
looking at
overall efficiency, and ease of quenching.

Comments welcomed,

John Freau