Re: RSG and NST's

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: FutureT@xxxxxxx 

In a message dated 11/26/04 2:38:55 PM Eastern Standard Time, 
tesla@xxxxxxxxxx writes:


> > Original poster: "rb" <randyaz@xxxxxxxxxxxx>
> >
> > Several posts lately are discussing the use of rotary spark gaps with
> NST's.
> > I was under the impression that a RSG was not for use with NST's as they
> > cause them to fail.  Is this not right?
> >
> > randyaz


Randyaz,

In the old days, it was usually said that RSG's were not good
for NST's and would destroy them.  Indeed this often happened
because folks used non-synchronous rotaries and often ran
them too slow, along with the use of resonant sized capacitors.
This permitted high voltages to develop and destroy the NST's.

Skip Greiner was the first person that I knew who used a 120 bps
synchronous rotary with an NST, and he had discussed this
with me at the time.  Skip got good results and I decided to
try the same thing.  I also got considerably longer sparks
than folks were typically getting for a given NST rating.  In some cases I
used an LTR value capacitor although it wasn't called that at
the time.  Eventually Terry also built such a system and did
further studies of their behaviour as did other folks.  I had
began calling this an LTRS system which Terry and others
shortened to LTR.  The use of the LTR system offers two
advantages; 1) it keeps the voltage lower in general,  2) it
prevents resonant voltage build-up in the case of a missed
firing or other problem.  NST's are rather fragile critters of course.
Later I devised a simple electronic phase shifter circuit for
easy remote adjustment of the rotary phase.  Terry offered some
safety improvements which I incorporated into the design.

At my website I show my TT-42 coil which uses such a 120 bps
sync-rotary LTR system.  I also show some vacuum tube coils,
some rotary spark gaps, and I also show the various spun aluminum
toroids that I make available to Tesla coil builders.

John