Re: tubes and windings

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

Original poster: "Grayson B Dietrich by way of Terry Fritz <twftesla-at-uswest-dot-net>" <electrofire-at-juno-dot-com>

Hello, Fox

On Wed, 13 Dec 2000 11:22:49 -0700 "Tesla list" <tesla-at-pupman-dot-com>
writes:
> Original poster: "Matt Skidmore by way of Terry Fritz 
> <twftesla-at-uswest-dot-net>" <fox-at-gwydion.woozle-dot-org>
> 
> ihad a friend over to take a look at my POS coil made of junk. she 
> was
> rather impressed and suggested i use a vacuum tube for the spark 
> gap. she
> is rather crazy with tubes and has a HUGE collection of them and 
> various
> radioactive materials. right now, i know nothing of how tubes work, 
> or how
> well they work on coils if you could get a nice 120 BPS. is it 
> possible to
> use an air or rotary gap now and then switch to a tube at later 
> time? 

I think that the redesign wouldn't be to critical, if needed at all. She
probably is referring to using a thyratron in place of the spark gap.
I've never used them, but to my understanding they act like a low-loss
triggered spark gap, and can even be set up to be self-triggering. I know
a few people have built coils using thyratrons, and I'm syre that's
they've replied long before I've gotten around to tis message.

or
> does the coil have to be redesigned to use a tube and its not worth 
> the
> trouble?
> 
> another question, how would one go about winding a seoncardy fairly
> easily? i intend to do it by hand, but if anyone has suggestions im 
> open
> to them. 


A winding jig isn't too much trouble to throw together. The last few
coils I've wound (a 2.5"X12", 3.5"X15", and a 2.5"X18") were done on
something that took me about an hour to make from stuff just hanging
around. For the drive, I used an electric hand drill. Locked into the
chuck was a bolt that I had attached to the eye-balled center of a pvc
pipe end cap of the needed diameter. I put a small piece of wood into the
cap to prevent the pipe from entering too far and thus too snugly to be
removed when the winding was finished. The drill had a convenient tapped
hole on one side that I connected to scrap piece of wood screwed to a
2X4, which was clamed to my work bench. At the other end of the pipe, I
used a combination of a motor, pulley, old-school style skateboard wheel,
and softball batting cage type ball. The pulley was locked onto the motor
shaft, which the the wheel sat up real nicely against, and the ball sat
nicely centered into the wheel. The other side of the ball fit against
the pipe. When the motor mount (again, another piece of 2X4) was clamped
down so that everything was squeezed together, from the hand drill to the
pulley, it worked fine. I used a variac to control the voltage to the
drill and kept the run times short, chekcing the drill for excessive heat
production frequently. It never seemed to get anything more than a little
warm.


what do you do if you need to stop in the middle of 
> winding? put
> a peice or tape or putty to hold the last few windings in place or
> something?

A little piece of electrical tape always seems to work for me. Masking or
duct tape are fine too. Celophane as well, I guess. 

> 
> thanks!
> 
> -fox

Have fun and good luck,


Grayson Dietrich
http://www.electrophile.8m-dot-com


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