Re: Spark gap construction

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Bert Pool" <bert.tx@xxxxxxxxxxx>

These copper pipes get HOT!  PVC would probably last about a minute.

You might try what I've successfully done:

Small ceramic or porcelain cylinders work well as supports (four per copper 
cylinder, two if you can find long ones) - I have found these ceramic 
insulators at ham fests and electronic junk places. Lay the ceramic 
cylinders down on their sides and epoxy them down - lay the copper cylinder 
on top of them.  Copper cylinder gaps always pit & corrode during use,  You 
can rotate the cylinders and expose a fresh surface!  Eventually you do 
have to sand them down to clean them.

( http://www.electronicsurplus.com/ ) has some very cheap insulators that 
would probably be suitable:

H H Smith Ceramic Standoff
H H Smith number 2538 bushings. Threaded ceramic insulators 1/2" long and 
3/8" in diameter with 6-32 threaded holes in each end.
04Z038 Unit Price : $0.65

Cheap, simple, and easy to do.

You can probably find other sources out there.

Bert Pool




At 04:08 PM 11/28/2004 -0700, you wrote:
> Original poster: "Black Moon" <black_moons@xxxxxxxxxxx>
>
> Iv seen alot of spark gaps using common copper pipe, and was wondering if 
> PVC pipe would be a suitable support for them, also, do they tend to arc 
> near the edge of the pipe? I was wondering if it might be benifical to 
> crimp the ends slightly. As for the safty gap, Should i try and find some 
> balls? or will 3 pipes do just as well? I assume I set the safty gap by 
> running the NST alone with no tesla coil and opening the gap till it just 
> barly arcs over the gap?