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Infinite Q almost
All,
Wow! I just returned to work from a three day weekend and 96 E-mails!
93 were the Tesla list since Friday! I have had to remain silent on a
lot of the messages due to time constraints.
I work in the lab all weekend. I made a number quatitative measurements
promised earlier and am preparing yet another article for the ESJ. The
results are pretty exciting at first glance.
This post has to do with Richard Cravens post about he and Malcolm's
discussions about Q which we have done a lot of work on here in Richmond
too.
I wanted to elimenate a number of nasty dependent variables from the TC
which would not allow comparing single changes to the system for
electrostatic data collection. (coupling, Quench, loading/tune upsets,
etc.)
I tryed a stunt which I believe was first noted by Tritchel in the late
30s (Physical Review- I think?? Can't site the specific ref, But I have
it here somewhere). I did away with the primary tank circuit and just
used a DC 15KV supply with the positive lead to a spark gap and negative
to ground. The other side of the gap went to a resonator which could
have its terminal loading altered dramatically. The system, when in
operation, drew and averaged DC current from the supply of .1-.5 ua!!!
(1.5-7.5 milliwatts.) The spark in the 1mm gap inaudible and invisible
in normal room light I am still analysizing this, but it appears that
the Q of the system goes to the moon as I counted 98 ring down pulses in
the resultant resonant pulsing. Expanding the sweep to include only 4
cycles of the ring showed little or no decrement! Needless to say, zero
spark from the resonator, but lotsa' DC! Positive only in this case. I
have about 20 oscillograms from the Tek digital scope and printer. There
are three periods associated with the system. Tritchel's 1930's
instrumentation was not up to the finer capabilities of todays scopes.
As a matter of fact, he used a radio to detect the RF portion of the
signal which was riding on a long DC pulsed exponential decay wave!
This long ring down is due to the virtual zero loading and zero coupling
of the system's resonator. Thus the Q can approach a theoretical
maximum. Most Tesla systems which produce spark might get 3-5 rings at
most. This points up a number of points in Richard Craven's post.
More as I pour over the data.
Richard Hull, TCBOR