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Re: First big magnifier run
At 06:25 PM 2/2/97 -0700, you wrote:
>Subscriber: nikki-at-fastlane-dot-net Sun Feb 2 17:27:19 1997
>Date: Sun, 2 Feb 1997 00:58:37 -0600 (CST)
>From: Bert Pool <nikki-at-fastlane-dot-net>
>To: tesla-at-pupman-dot-com
>Cc: jgore-at-cyberramp-dot-net, bemery-at-why-dot-net
>Subject: First big magnifier run
>
>Wild Bill Emery and I finally set up our large magnifier out in my driveway
>Saturday night and fired her up. We started with a 40 inch by 5 inch toroid
>on top of a 4 inch by 13.75 inch resonator coil (30 gauge). We video taped
>the runs, and then measured honest 90 inch strikes to the house and garage
>door frame. After running it, we found that I had failed to lock down one
>of the stationary electrodes on the rotary gap, and it had opened up to over
>1/2 inch gap, and it still worked! We will redo the gap on our next series
>of runs.
>
>We first experimented with using the secondary in the driver as a
>conventional Tesla coil. It is only about 180 turns of 10 gauge wire on a
>16 inch diameter pvc pipe, so inductance is not much. We tried the 40x5
>toroid as well as the 60x8 inch top, and all we ever got was sparks racing
>down the secondary - and this was with the coupling about as low as we could
>go without raising the secondary up (it weighs 107 pounds, so raising it up
>a foot or so is no small task.) We finally gave up on trying to use it as a
>conventional coil, and decided to use it as a driver, as it was so designed.
>
>What was absolutely incredible during this "conventional coil" attempt is
>that we had some extremely hot, violent arcs from the toroid down to the
>primary. Sometimes, but not every time when this happened, we got 23 inch
>flashovers from the bottom of the primary to the concrete driveway! We have
>the entire coil assembly sitting on top of 22 inch tall porcelain
>insulators, and the primary arced all the way to the concrete, jumping
>AROUND a 3/8 inch copper line run straight to my water main. I am still
>stunned at seeing this. I repeatedly watched this frame-by-frame on video,
>and it is weird. Apparently there is ground, and then there is ground. My
>main ground is 3/8 copper tubing screwed directly to a brass water faucet on
>the front of the house. The faucet is connected to a copper water line
>which immediately runs 30 feet under the yard to the water meter, and from
>there to the water main under the street. I dug up a section of the line
>from the meter to the house to make sure it was copper before I ever used it
>as my coil ground. I figure 30 feet of buried copper line connected to a
>buried water main is a damn good ground, so why would a strike to my
>concrete driveway just ignore a copper ground line connected to this superb
>ground? The arc had to bypass the best ground I can make and instead opted
>for some crummy concrete. I know the copper water pipe ground is adequate,
>as my coil is performing quite well. Those 23 inch strikes to the driveway
>passed within one inch of my ground and absolutely ignored it.
>
>Anyway, we will put the much larger top on the resonator coil next time and
>we should get much longer sparks. Our goal is to go beyond 10 feet, and
>with 7.5 feet on our first run (and this was using our first "best guess"
>primary tap setting!), I think we are well on our way there.
>
>I shot about half a roll of 35 mm film of the coil's driver construction,
>and I'll get this developed and scanned next week, I'll pass it on to Chip.
>I did not shoot any film of the coil running yet, only video. I'll take
>some stills the next time we run it. We're going to wind two new resonator
>coils, one will be a 12 inch diameter pvc pipe wound with 18 ga wire, and
>one will be a monster 16 inch diameter coil wound with 10 gauge. This is
>getting to be a lot of fun!
>
>We're running a 20,200 volt transformer, which is very loud on the rotary
>gap. I had several neighbors standing in their yards watching the show. I
>wish I had a large building to run this coil in, but unfortunately my yard
>will have to do. I think I'm moving it all to the back patio for my next
>test run to reduce the neighborhood interest. I figured on my first run if
>I even got it to break out of the toroid, I'd be doing good. I didn't expect
>90 inch sparks and didn't want to generate quite so much neighborhood interest.
>
>Bert Pool
>nikki-at-fastlane-dot-net
>
>Bert, Wild Bill,
Welcome to the maggey fraternity!!! Incredibly fine work! Keep it up and
let us know the result of those monster resonators you have planned.
Richard Hull, TCBOR