Re: Inexpensive drawer-pull spark gap electrodes

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux by way of Terry Fritz <teslalist-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

This would more of an issue for a TC, where the spark rep rate is quite
high, as compared to a Marx generator.  For TC's I think the optimum low
buck/low effort electrode is probably chunks of copper pipe (if you have a
tubing cutter and time) or sweat couplings (if you don't, or the slightly
higher capital expenditure is worth more than an hour cutting tubing).  Lots
of surface area, lends itself to air cooling, etc.


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Tuesday, May 27, 2003 4:46 PM
Subject: Inexpensive drawer-pull spark gap electrodes


 > Original poster: "Scott Hanson by way of Terry Fritz
<teslalist-at-qwest-dot-net>" <huil888-at-surfside-dot-net>
 >
 > A note of caution on using the "cheapie" drawer pulls as spark gap
 > electrodes.
 >
 > All the inexpensive ones I have ever seen were die-cast zinc with a very
 > thin brass, nickel, or chrome plating. If used as electrodes in a primary
 > spark gap, the thin plating very quickly erodes away exposing the zinc.
The
 > zinc has relatively low vaporization temperature and develops problems
with
 > quenching as soon as the electrodes begin to heat up. The effect is much
 > more pronounced with 60ma or greater supply current.
 >
 > Solid brass brawer pulls are available, but are harder to find and are
 > considerably more expensive than the zinc ones.
 >
 > Regards,
 > Scott Hanson
 >
 > These work fine as safety gap electrodes, but
 > ----- Original Message -----
 > From: "Tesla list" <tesla-at-pupman-dot-com>
 > To: <tesla-at-pupman-dot-com>
 > Sent: Monday, May 26, 2003 6:23 PM
 > Subject: Re: Tuning Troubles
 >
 >
 >  > Original poster: "Dr. Resonance by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <resonance-at-jvlnet-dot-com>
 >  >
 >  >
 >  > For great spark gap balls at a great price, go down to Home Depot in
the
 >  > cabinet section.  Look for the "drawer pulls".
 >  >
 >  > Specifically Liberty Hardware p/n P1061C-CHR-C.  It is approx. 1 1/8th
 > inch
 >  > dia. and has a chrome finish.  Very solid and comes with a mounting
 > mounting
 >  > bolt.  They also come in same size with brass finish.
 >  >
 >  > The great part is these balls are only $2.39 each!!!   You can make a
nice
 > 3
 >  > electrode, 2 gap, sparkgap for under $10!!
 >  >
 >  > Dr. Resonance
 >  >
 >  > Resonance Research Corporation
 >  > E11870 Shadylane Rd.
 >  > Baraboo   WI   53913
 >  >  >
 >  >  > Eight spark gaps may be wasting excessive energy in the form of heat
 > and
 >  >  > light --- especially heat.  You might try just one or two gaps for
best
 >  >  > efficiency.  On most of our 30 mA and 60 mA coils we use just three
1/2
 >  > dia.
 >  >  > tungsten electrodes to form 2 sparkgaps.  Only on the 60 mA units do
we
 >  > add
 >  >  > a 100 CFM fan behind the gaps.  30 mA doesn't require any cooling at
 > all
 >  > for
 >  >  > best quenching.
 >  >  >
 >  >  > Also, experiment with elevating your sec. coil in 1/2 inch
increments
 >  > until
 >  >  > you hit the best coeff. of coupling.
 >  >  >
 >  >  > Dr. Resonance
 >  >  >
 >  >  > Resonance Research Corporation
 >  >  > E11870 Shadylane Rd.
 >  >  > Baraboo   WI   53913
 >  >  >  >
 >  >
 >  >
 >
 >