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Re: sunc gap? tuning w/ o-scope?


	Don't be at all surprised if the highest primary voltage occurs FAR after
the peak in the waveform.  The resonant nature of the primary circuit is
such that the highest voltage point is after the peak in the waveform.
That sounds funny, it is kind of hard to explain.  If you back up the
timing to hit the peak, the whole signal decreses to a lower voltage and
you are worse off than before.  By far the best way is to set the gap
timing for the biggest output sparks.  It really is just that simple.  You
can get into all kinds of fancy theory and measurements but trial and error
to find the biggest arcs is really the fastest, and simplest way to set the
gap.  A insulated handle or something that would allow you to turn the
motor while the coil is operating allows very quick and easy adjustment.  I
can now sync my gap with the flourescent lights after a little experience.
Mine needs to be set about 40 degrees off from the peak.  I have a bunch of
papers at:

www.peakpeak-dot-com/~terryf/tesla/experiments/experiments.html

that show actual wave forms and such.

	I prefere a simple easy to get and plug into the scope scanner type
commercial antenna for simple TC scope input.  They are a little larger and
allow the antenna to be set at a nice safe distance.  If you want to make
real measurements of values and such then you need something better like
plan wave antennas.  However, inserting a 50 ohm terminating resistor at
the scope input with a few BNC adapters will clean up the waveforms of a
scanner antenna remarkably, but not needed for simple stuff.  I could go on
and on... but this should do for now...

	Do be very sure that the coils high primary or secondary voltages NEVER
accidently make their way directly into the scope input.  The destruction
would be instant!!  Like my friend Mike the RF guy says.  Yep... That's why
I like them four channel jobs.  Ya can make four mistakes before ya gota
send the darn thing in for repair. :-))



	Terry



At 10:24 PM 2/23/99 -0700, you wrote:
>to: Ross
>
>A small "antenna" fashioned from a simple 3 inch long wire is located via a
>coax cable (shielded) at a distance of usually 2-3 feet away from the
>operating primary coil (exact distance depends on how large your system is).
>Secondary coil can be in place or simulated with a 30 Ohm 2 kva resistor
>(nichrome heater elements) connected across the primary coil to simulate the
>secondary "load" condition.  The system is run and the o-scope will display
>the sparkgap firing and show at what time along the 60 Hertz waveform the
>spark gap actually "fires".  If it is not at the peak of the charging 60 Hz
>waveform then the rotor is adjusted on the motor shaft and the process is
>repeated.  Eventually you will get the system firing right at the top of the
>60 cycle peak (actually 2-5 degrees past is best) and your synchronous
>rotary gap will be delivering energy as the capacitors reach full charge.
>
>You might also wish to check the archives --- I believe John Freau and Terry
>Fritz have posted some data on this antenna construction.
>
>Regards,
>
>Dr.Resonance-at-next-wave-dot-net
>
>
>-----Original Message-----
>From: Tesla List <tesla-at-pupman-dot-com>
>To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
>Date: Wednesday, February 24, 1999 2:11 AM
>Subject: sunc gap? tuning w/ o-scope?
>
>
>>Original Poster: Ross Andrews <sflourine-at-home-dot-com>
>>
>>
>> Hi,
>>
>> I just have a couple questions for you more experienced coilers out
>>there:
>>
>> -Many people on this list have talked about "120 bps sync gaps".  Am I
>>correct in thinking that this is a rotary gap driven by a synchronous
>>motor?
>>
>> -I understand the prospect of tuning a coil by the "trial-and-error"
>>method, but I have also herd of tuning it with an o-scope.  Is this
>>feasible?  How is it done?
>>
>> Many thanks,
>>
>> Ross Andrews
>>
>> sflourine-at-home-dot-com
>>--
>>If you want to know what God thinks about money, look at the people he
>>gives it to.
>>
>>
>
>