From: "Terrell W. Fritz"
Date: Wed, 20 Mar 2002 23:09:21 -0700
Subject: Re: [TSSP] short H/D and stuff
Hi All, I have begun construction of the test coil for Paul's secondary current/Q experiment. Here are some pics: http://hot-streamer.com/temp/P3200029.JPG http://hot-streamer.com/temp/P3200030.JPG It is # 24 wire wrapped around a plastic bucket. The first windings are held by super glue so they don't slide off the slightly conical end. Super glue is perfect for this. It invisibly locks the windings right in place. I have PC board header connectors that are just 0.1 inch pins bent over to accept the ends of the wires in each band. They go to the inside to pins that can be shorted with simple little shorting blocks like those used on computer boards. I think this arrangement will have minimal impact on the coil's electrostatics. Hopefully, I can get it done by the weekend. I am getting the RS-232 thing for Paul's "Q vs. weather and 'stuff' test". Looks like a load of fun there!! The coils can be set up just about anywhere with only a single coax coming back to the scope. A computer can pick off the data and stick it to a big drive via Ethernet. Maybe Paul can get software to me here so I can do the Q calculations rather than sending the files off to him since they can get kind of big. But not too big really in any case. To get around the tiny signal strength problem, I am pumping about 2500 volts in the coil and shorting it to ground. That gives a good strong ring down signal that is easy to pickup :-) I have to be a bit careful not to attract the FCC running it 24-7, but that should be of little worry. I have to find a HV supply to run it. My old fluke does not have enough voltage and the Bertan is sort of scarry leaving on all the time. The "off" switch does not turn it off anymore =:o)) Maybe a bad switch or something in the digital electronics. I think Sue Grata used to work for Bertan so I E-mailed her to see if she knows anything about it. Probably just fix up an ignition coil thing or get a bug zapper transformer for the testing. I do have a 15/120 NST too... Hmmmmmm, but 100 pounds so hard to move it around. The other NSTs are needed for running the regular coils like at next weekends local Tesla meeting. But in any case, getting high voltage should be easy around here :o)) Scott Fusar gave be some neat ideas about calibrating plane wave antennas for top terminal voltage measurement. Basically, just charge a coil to a given voltage and short it to ground or use an NST to put in a known voltage on the coil. One can check linearity and all kinds of critical parameters that way to insure that a read off voltage is the "true" voltage. He also sent me a bunch of Rogowski coil info... Jon Tebbs found me a Pearson 101 current monitor for $100. 100:1, 50,000 amps peak, 200 amps RMS, 0.25Hz (1/4 of one Hertz!) to 4MHz response, and a big 2 inch hole to get 'real' wire through :-))) I have been looking for a real high current puppy like this for a year now. The 411 can do 5,000 amps but it pushes 500 volts into the scope which is "hard" on things. 100:1 ratio is far better! Got the latest and greatest firmware uploaded to the scope. A few new cute features and some refinements in speed and accuracy. Upgrading firmware things is always scarry, but it went very well. Fixed hot-streamer's blown network stuff and have lots of 'extra' ports to blow up now. ;-)) I also got a flat screen monitor for it so it uses like 5 watts average instead of 250 watts 24-7. I was stunned to figure that I was paying $15 bucks a month to run the old 17 inch monitor... But the room is cold now instead of nice and warm :-)) It should survive power outages on the UPS like 10X longer now too. :-)) Flat screen is really nice!!!! I got the fancy $450 Viewsonic VE150 but the prices are going to still drop far. There are some cheap ones in the 300+ dollar range but they are "cheap"... Flat screen TFT LCD is going to be a "big deal" very soon... The LabCam seems to lock up around running Tesla coil stuff :-p 20 feet of USB cable... But I think people get a big kick out of seeing me goofing around Tesla coil lab :o)) So I really am doing stuff here :-)) Cheers, Terry
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.