78 inch strike from MOT coil!

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

Original poster: "Jason Johnson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <hvjjohnson13-at-hotmail-dot-com>

I believe that I have just set a new spark length and efficiency record for MOT
coils! I got three 74" strikes in a single run from my MOTcoil, and one
confirmed (we had three people see it and measured it 4 times because I almost
couldn't believe my eyes) 78" strike! The coil is running with a new 460 bps
async rotary gap (geeks see my other posts on tungsten carbide rotary spark
gap, on the geek list) that I built with 1/2" tungsten carbide squares, on a 6"
Al rotor, and two 1/4" brass threaded rods for stationaries. I just completed
the gap the other day and fired it up for the first time on the coil 3 hours
ago.  This is even more amazing when you consider that I'm running on a 120
volt 15 amp breaker, and haven't tripped it once since I added the new gap,
this is also with a 20 amp fast blow fuse in there, so I wasn't overloading the
breaker much, if at all, and I'm cranking the variac all the way up and running
for minutes at a time. I'm running 2 MOTs in series for about 4800 volts with
no voltage doubler, protection filter or even a safety gap! This gap makes my
MOT coil ROCK! The strikes were all to a ground rod, sparks were all seen by
me, my dad, and my friend, and measured from the tip of the breakout point to
the ground rod, straight line distance. None of these measurments uses
estimated lengths from curvy sparks etc, just point to point measures. 
 
Jason Johnson
G-1 #1129