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Re: Character Revisited


Very interesting.
Barry

 ----------
|From: "tesla-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
|To: Benson Barry; "Tesla-list-subscribers-at-poodle.pupman-dot-com"-at-PMDF-at-PAXMB1
|Subject: Re: Character Revisited
|Date: Tuesday, November 26, 1996 3:58PM
|
|<<File Attachment: 00000000.TXT>>
|From rwall-at-ix-dot-netcom-dot-comTue Nov 26 08:03:08 1996
|Date: Tue, 26 Nov 1996 05:20:01 -0800
|From: Richard Wayne Wall <rwall-at-ix-dot-netcom-dot-com>
|To: tesla-at-pupman-dot-com
|Subject: Re: Character Revisited
|
|11/26/96
|
|Forwarded post
|
|>>>>
|
|Rick,
|
|Sure, no problem.  Please be sure to state that this was very informal
|testing.  I was really trying to prove that tube and transistors could
|each do the job well to an old, die hard tube fan, and just screwing
|about in general.
|
|Were I going to publish any of this, I'd want to revisit some of the
|testing, and have learned a bit more about how the RF wattmeter acted
|to less spectrally pure signals, etc.
|
|I would not describe these results as definitive, but they did show
|that for the one secondary coil tested, the spectral content had more
|to do with delivered arc length than did the driver technology.
|
|In all this messing about, there were two specific drivers that might
|be exceptions, but I suspect this probably had more to do with
|impedance matching than anything else.
|
|An argon thyratron made a really frighteningly good driver.  One cold
|winter night we had corona everywhere, while angry masses of plasma
|danced inside the tube. St. Elmo's fire oozed along the plate
|electrode and the ozone grew so thick we pulled the plug for fear of
|damaging the secondary insulation.
|
|No attempt was made to measure of control the spectral content, but
|the DC input power was rather low for the display we received. (I
|would not have brought my test equipment NEAR that thing!)
|
|A similar display was given by an old diathermy machine that was given
|to me by Bob (Mr. Tesla coil) Golka himself.  This ancient example of
|state of the art electronic snake oil uses a pair of self oscillating
|triodes with exceptionally thick plate structures.
|
|While these oscillate at a frequency quite a bit above the self
|resonant frequency of the coil we used, it was quite spectrally broad,
|being a sort of odd, square wave multivibrator circuit.
|
|This drivers shows that indeed, the higher the frequency, the longer
|the arc for a given power level.  You know, I was just cleaning up in
|the basement, and I ran across that old diathermy machine chassis. I
|wonder what ever became of that thyratron?
|
|This is a guess, but if you were to drive a given coil at it's
|fundamental, and push the even harmonics was up (dV/Dt?) so that there
|were lots of higher frequency harmonics, I think you would find
|greater arc lengths for the same input power.  That's how I recall
|things acting.  It makes some sense on conventional, and less
|conventional levels.
|
|snip . . .
|
|Oh yes, the die hard tube fan grumbled a lot, and pointed out that the
|thyratron and diathermy machines both made more impressive displays,
|with less circuitry than did ganged solid state amps.  The primary
|power levels were a different story, so we agreed to disagree.  He
|forever did gain a respect for Phase Linear power amps though, even of
|here chock full of bipolar transistors!
|
|
|>>>>>>
|
|______________________________ Reply Separator
|_________________________________
|Subject: Re: Got your emails.
|Author:  rwall-at-ix-dot-netcom-dot-com (Richard Wayne Wall) at SMTP
|Date:    11/23/96 7:18 AM
|
|
|11/22/96
|
|
|May I forward portions of your posts to the Tesla List.  I think they
|would be extremely intereted in your experiments mimicing gap
|discharges with solid state drivers in TCs and getting similar outputs
|from the secondary.
|
|This is original research and you might consider publishing.  But, I
|know your time constraints.
|
|RWW
|
|
|