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60 BPS sync TC tests

+++++++
I'm reposting these old results for the benefit of new list members
and to compare with my recent 60 bps tests.     JF

<< ----------
 From:  FutureT-at-aol-dot-com [SMTP:FutureT-at-aol-dot-com]
 Sent:  Wednesday, February 25, 1998 12:56 PM
 To:  tesla-at-pupman-dot-com
 Subject:  60 BPS sync TC tests

 
 Greetings all, 
 
 Prior tests showed good performance at low break rates (120 BPS
 synchronous), such as 42" sparks at 640 watts, 46" at 700 watts, 
 64" sparks at 1560 watts, etc.  Higher break rates were worse,
 so I figured it might be useful to try an even lower break rate.
 
 I modified my 1800 rpm sync gap by removing 2 of the spinning
 electrodes (leaving 2 in place), and I doubled the size of my tank
 capacitor.  By removing the electrodes, the gap now fires only
 on every other half cycle or 60 times per second.  I'm using a
 potential xfrmer and adjusting an external inductive ballast for
 best operation.  
 
 The performance was quite interesting and quite good.  I'm now
 obtaining 45" sparks at 600 watts, at 60 BPS.  The sparks appear
 dimmer, and less bolt-like than at a higher break-rate, but the sparks
 have quite a wonderful way of slowly reaching out...and out, to reach
 the measuring wire.  The sound at 60 BPS is unique in itself.
 
 I also did some tests at a little higher power, here's a chart of all the 
 results:
 
   ___________Watts         120 BPS          60 BPS
                        600              -----                 45"
      small          640               42"                ----
      toroid          700               46"                ----
   ____________800               ----                 49"
       large          900               ----                 55"
   __toroid_____1560              64"               -----
 
 Unfortunately I did the tests at different power levels which makes
 it a little harder to interpret.  In some cases the coil was most
 "happy" at a certain power level, although I could probably obtain
 results for comparison at identical power levels, and I may redo
 the tests with that in mind.
 
 The primary is still #12 wire, but considering the 
 larger *bang* size, a thicker wire should be used.  The 60 BPS 
 set-up outweighs this negative to deliver impressive performance.
 
 It is possible that a 60 BPS system could be driven by a level
 shifted (voltage doubler) type power supply which would allow both
 (positive and negative) cycles of the 60Hz AC to be utilized, and
 permit the use of lower voltage transformers.  In such a system,
 the sync gap would have a 50 - 50 chance of starting up on the
 correct AC half cycle, so this would have to be kept in mind.  Also
 RF kickback issues would need to be addressed.
 
 (update:)
 It is possible that NST's would not fare well in this system due to
 potential resonant voltage build-up conditions, although this could
 be overcome to an extent by using LTR caps.
 
 John Freau
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