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Sanity Check for me


----------
From:  Chuck Curran [SMTP:ccurran-at-execpc-dot-com]
Sent:  Tuesday, March 17, 1998 9:21 PM
To:  Tesla List
Subject:  Re: Sanity Check for me

Michael:

There is a growing number of Coiler's whose families are pretty sure we are
all a bit touched, based on this hobby!  The bigger the coil the more
kidding you will get.  I made a coil last year with 15 1/4 " O.D. PVC sewer
pipe and I was pleased with the results.  I took the piece I had and let it
sit in my basement for a long time, a basement with about 20-30% relative
humidity.  I wiped down the I.D and O.D. with xylene and then coated it with
a clear polyurethane sealant.  So far, it has worked well enough to keep me
content.

The advice that you already received is important enough so I'll repeat it.
I would highly recommend going with a heavy wire gauge, at least #16 or even
bigger.  The space winding technique is what I am currently going to use on
the coil I am presently building.  Bert offered very good advice in this
area.  The PVC form I mentioned above I did not space wind, but the new one
will be since it is much bigger.  It might help to list out some estimated
component costs for a big coil like this.  You can always improve on these ,
but these are representative of what you could order them for tomorrow.

10 Kw pole pig--$290.00 from T&R Electric (changes by the day)
Superior 1256D auto transformer 0280 VAC -at- 28 amps--$300.00 from C & H
Supply (used)   about $800.00 new.
Current limiting arc welder--$190.00   any Builders Square,  or Home Depot
type store
Pulse Discharge Caps, new  -- .025 mfd $210.00,    .05 mfd $540.00,   .1 mfd
$580.00  (recent quote from Plastic Capacitors, Inc., last two)
Copper Magnet Wire for Secondary--Figure $4.00 per pound and up as a minimum

That's just the big items.  Now add to that the various other required
details, meters, current transformers, contactors, hook up wire, crimp
connectors, cords and plugs, rotary gap, cabinet, coil base, EMI/RFI
filtering, toroid,  ground system, primary copper tube -- yup, it's easy to
spend a bit pretty quick.  Then when your all done and it is debugged and
working, you'll go out and make sure to take some good timed exposure
pictures and have a few enlargements made--might have to buy a camera!

It 's really a great hobby and it can be done for much less if you have Ham
Fests that occur near you.  Many items can be picked up at a fraction of
their normal list price.  I've had a great time building my coils and I'd
highly recommend going for it with your big form, if you've already built a
number of smaller systems--just skip some mortgage payments!!  Have fun with
your project, you will not be wasting your time.

Chuck

-----Original Message-----
From: Tesla List <tesla-at-pupman-dot-com>
To: 'Tesla List' <tesla-at-pupman-dot-com>
Date: Tuesday, March 17, 1998 2:06 AM
Subject: Sanity Check for me


>
>----------
>From:  baumann-at-proton.llumc.edu [SMTP:baumann-at-proton.llumc.edu]
>Sent:  Monday, March 16, 1998 3:45 AM
>To:  tesla-at-pupman-dot-com
>Subject:  Sanity Check for me
>
>I have the opportunity to get a rather large diameter chunk of PVC,
>and am now dreaming of that monster coil. However, when I start running
>the numbers - I need a sanity check from some of you more familiar with
>this size beast:
>
>What I have the chance for is some 18" diameter PVC, in about 6ft
>sections. Leaving my sanity out of the question for the moment, i
>thought this would be a rather nice coilform.
>
>Then I started running numbers:
>If I use 18AWG wire, WinTesla tells me that at 44inches, I would
>have an unloaded frequency of about 77Khz, at an HD ratio of 2.35
>This is about 1000 turns and about 5000 ft of wire.
>
>If I use 22AWG still aiming for 1000 turns: ratio drops to 1.5 (27")
>and frequency to about 70Khz
>
>
>
>
>I would assume the 18AWG is required to keep the resistive losses
>down.
>
>Throw a 6"x36" toroid on there, and the frequencys drop to the
> 40khz range, and the cap size jumps from about 0.03 to 0.07 for 22awg
> and from 0.02 to 0.05 for the 18AWG, operating frequencies drop
> into the 40Khz range
>
>Primary would be close to 100ft of tubing if I used 1/4"
>
>Would I be wasting my time? And if so, is there a use for this
>large PVC that I don't see? [It's going in the trash unless I find
>a use..]
>
>
>
>--
>--
>Michael Baumann  Optivus Technology Inc.|Loma Linda University Medical
Center
>San Bernardino, California. (909)799-8308 |Internet: baumann-at-llumc.edu
>
>
>