Re: PVC diameter and cap question
I'd say that the myth of 'not drilling' is still a valid rule, since
effectively by inserting the disks you are closing the form.
The bits above and below these end disk then appear simply as
extensions to this main, sealed form.
I think that the idea is to *not* have a hole near the top and bottom
of the windings where they can 'see' each other. The distortion such
gaps would produce in the internal electric field would be asking for
a breakdown. I think this would explain why a 'squirrel cage' open -
wound form is OK, as the dielectric is more or less all air, and the
field should be quite uniform. However I would always prefer something
more substantial between my 1MV and earth!
On Sun, 13 Jun 1999 01:19:00 Tesla List wrote:
> Original Poster: "Dr. Resonance" <Dr.Resonance-at-next-wave-dot-net>
> to: Don
> We put holes in our sec coils with all coils less than 10 inches dia. This
> is no problem at all. Just silicone in place two 1/4 inch thick acrylic or
> PE disks. Sand them for a very tight fit and tap them in each end approx 4
> inches down. Apply the silicone and let dry for 36 hours for complete cure
> before sealing up the sec. ends.
> As soon as the magnet wire enters the sec tube solder it to a small piece of
> flexible 20 AWG stranded wire. Cover this with a piece of tygon tubing.
> Apply generous amounts of silicone to the entrance point (approx 3/4-1 inch
> thick) and over the brass bolt that feeds the ground out --- and also the
> top HV out. We use 5/16 inch dia brass bolts or studs on all of our smaller
> Lots of silicone and the disks with destroy this myth of not drilling into
> the sec coil. Been doing it this way for 35 years -- and never a single
> With larger coils and pole xmfr operating units we still use the disks. We
> bring the grond end inside for connection to 1/2 inch dia brass studs, but
> keep the HV end outside and slowly spiral it up to the top toroid. We place
> the disks approx 10 inches in on each end with the larger coils with coil
> lengths of 5-10 feet long.
> -----Original Message-----
> From: Tesla List <tesla-at-pupman-dot-com>
> To: tesla-at-pupman-dot-com <tesla-at-pupman-dot-com>
> Date: Saturday, June 12, 1999 5:13 AM
> Subject: Re: PVC diameter and cap question
> >Original Poster: Don Allen <dona-at-amigo-dot-net>
> >At 06:31 PM 6/10/99 -0600, Tesla List wrote:
> >>Original Poster: "Jim Lux" <jimlux-at-jpl.nasa.gov>
> >>SDR also comes in white... I just scavenged a nice 10" diam piece about 5'
> >>long from the guys working on the landscaping at the bottom of my street.
> >>How do I know it is SDR? It is stamped on the side.
> >I went to a plumbing supply store and found a 6" SDR-35 pipe that I can
> >use. I've sanded it pretty well and it's just about ready to get dried per
> >method in a box with a lamp. Secondary will be 888 turns of #22 wire on
> >my homemade winding jig.
> >The 15Kv 60 ma NST that I bought from another coiler came
> >in via the post office, however the box was mangled and the insulator
> >around the 120v input sustained damage on the bottom terminal. By damage
> >I mean the insulator was in pieces. I took out a meter and put one probe on
> >case ground and the other on the terminal. No continuity, so the terminal
> >inside appears to be intact and isn't touching the case.
> >When the NST came in and I saw the damage, I freaked and I called a sign
> >company, thinking I could get a spare insulator. They don't do any neon
> >anymore but they put me in touch with a local NST repairman. He didn't have
> >an insulator, but suggested the "JB Weld fix". I used the entire set. It
> >I visited his shop today and bought another 15kv 60ma NST (old
> >from him for $25, so now I have two. While I could wire both of these
> >together and use them, I think it prudent to keep one as a backup, just in
> >I screw up or something blows.
> >I started out a few weeks ago with George Trinkaus's book on building a TC,
> >but I've learned a lot by reading other coiler's pages and looking at
> >designs. One thing that RQ is emphatic about is not putting any holes in
> >secondary coilform, where Trinkaus suggests drilling holes and running wire
> >inside the form. No holes are being put in my coilform and I'm doing my
> >per RQ's specs. It just makes more sense. Both ends will be sealed so no
> >of a spark getting inside the coilform. I think Trinkaus means well, but
> >I avoided what could have been a major headache if I had followed his TC
> >method. I did get a chuckle with Trinkaus use of a toilet float for a
> >capacitor. <g>
> >Question #1 - I like Gary Lau's primary design using 1/4" refrigeration
> >but for
> >a 6" coil, how many turns should it have?
> >Question #2 - Where can I find a variac?
> >Question #3 - I've been following discussions about the use of MMC's, but
> >there any kind of consensus what is the best type to use (least amount of
> >strings) ?
> >"Resistance to tyrants is obedience to God" - Thomas Jefferson