Inexpensive drawer-pull spark gap electrodes

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

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
 >  >  >
 >
 >