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Re: Rotary Gaps

>>From richard.quick-at-slug-dot-org Wed Dec 27 01:12 MST 1995
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>From: richard.quick-at-slug-dot-org (Richard Quick)
>Subject: Re: Rotary Gaps
>Date: Wed, 27 Dec 1995 02:22:00 GMT
>To: tesla-at-grendel.objinc-dot-com
>
>Quoting ed-at-alumni.caltech.edu (Edward V. Phillips):
>
>> Re: Volume 5 of Radiation Lab Radar Series
>> Richard:
>
>> You may have overlooked one comment there (can't quote
>> page and line as my copy is in my book case at work) which 
>> mentioned that the guys at Rad Labs tried some of the earlier
>> "radio transmitter" rotating gaps and found they didn't work
>> any better than the ones they eventually ended up with, which
>> mostly had pointed electrodes.  I have seen many radar 
>> modulatro (modulator) spark gaps, and all had more or less 
>> sharp points. The flat, wide electrodes came about because of 
>> the desire to keep the circuit resistance very low.  An 
>> "ultimate" ham transmitter at 200 meters (1500 kHz) used an 
>> 0.01 mfd capacitor, with a reactance of about 11 ohms.  Any 
>> circuit resistance at all knocked the primary circuit Q 
>> (increased the decrement) to pieces.  
>
>Yeah, I have noticed this. The points keep the dwell and quench
>times low.
>
>> Wonder what radar set used the rotary you mentioned,
>> with electrodes like a tongue depressor?
>
>The rotor electrodes were thin, say 3/16 inch, tungsten. Only the
>stationary electrode was flat, and mounted so that it would
>pivot. By pivoting the stationary electrode the dwell could be
>adjusted.
>
>Richard Quick
>
>... If all else fails... Throw another megavolt across it!
>___ Blue Wave/QWK v2.12
>
>
Greetings Tesla fans,
        The Corum brothers have shown interesting graphs of secondary 
induced voltage versus spark gap dwell time.  (There is an optimal spark gap 
dwell time (the time during which the spark gap is conducting) for maximum 
energy transfer to the secondary, which depends on a number of parameters.)  
My question is this, does anyone know how they carefully controlled spark 
dwell time in their experiments to create these graphs?   Just curious.
Regards,
Mark S. Rzeszotarski, Ph.D.