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RE: [TCML] Where to mount the HV Transformer? Under the coil orotherwise ?
Uh , RG-58 are you sure you don?t mean RG-8 or RG-11 size, even RG-8X has a
better HV rating then 58. I use a lot of different coax types on my antenna
systems but try to avoid RG-58. They only time I use RG-58 is for a balun
Rich , Kd0zz
As an act of plagiarism . Disclaimer: Any errors in spelling or facts are
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Sent: Wednesday, June 25, 2008 8:07 PM
To: Tesla Coil Mailing List
Subject: Re: [TCML] Where to mount the HV Transformer? Under the coil
Agreed! RG-58 is the way I would go. I use it for my antenna (CB), and
it's huge and heavy duty. I haven't used it for hv transmission, but
I've thought about it.
David, thanks for letting us know your success with the Green Monster
using RG-58. I've got "lots" of it and should put it to use. I assume
you stripped the rf braid back?
David Rieben wrote:
> Hi Jeremy,
> You would need the heavy duty coax cable, like RG-58?.
> That cheap junk that comes to the back of your cable TV
> box uses foam insulation and would promptly fail under the
> high voltage stress of Tesla coil transmission line service. I
> personally like to use surplus x-ray cable for this purpose.
> It is basically a coax cable on steroids and us usually rated
> at around 75 kVDC standoff between the inner conductor(s)
> and the outer braid. It is typically around 3/4" in diameter
> and I have had very good success using this as a transmis-
> sion line for the HV from my pole pig to my Green Monster
> Tesla coil. http://www.dawntreader.net/hvgroup/david/gm.html
> David Rieben
> ----- Original Message ----- From: "Jeremy Scott" <supertux1@xxxxxxxxx>
> To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
> Sent: Wednesday, June 25, 2008 12:36 AM
> Subject: Re: [TCML] Where to mount the HV Transformer? Under the coil
> orotherwise ?
>> I read the coax idea off of this site:
>> Somewhere in there it says this:
>> "The transmission line between your high voltage transformer and your
>> tesla coil is another potential source of electrocution. This should
>> be constructed using neon sign wiring (rated to 40 kV) or thick
>> coaxial cable like RG-8A/U or RG-11A/U. If using coaxial cable, use
>> the inner conductor for the high voltage, and strip back the outer
>> braid about 6-12 inches from each end. Connect one end of the braid
>> to your RF ground. Leave the other end unconnected so it does not
>> form a current loop. Some coilers also place their high voltage
>> cables inside a plastic conduit, which is laid on the floor. This
>> also protects the cable somewhat from strikes."
>> I was just wondering if anyone has any experience doing it that way.
>> This is basically the 50 and 75 ohm impedance cable that you can get
>> anywhere. They have a thick PTFE insulation between the core
>> conductor and the braid which I think would be ideal for isolation.
>> The braid being a nice additional safety feature.
>> On the other hand... just don't know.
>> It would be interesting to see just how much voltage it takes to pop
>> one of those cables.
>> --- On Tue, 6/24/08, MIKE BAILEY <m.bailey@xxxxxxxxxx> wrote:
>>> From: MIKE BAILEY <m.bailey@xxxxxxxxxx>
>>> Subject: [TCML] Where to mount the HV Transformer? Under the coil or
>>> otherwise ?
>>> To: tesla@xxxxxxxxxx
>>> Date: Tuesday, June 24, 2008, 4:42 PM
>>> I have my transformers mounted in my control cabinet and run
>>> coax cable out to my RSG mounted under the coil , seems to
>>> work good no problems so far. I would not connect the
>>> braided part of the coax to rf ground , if there are any
>>> weak areas in the insulation between the center conductor
>>> and the braid or any microscopic holes it will eventually
>>> fail and you will have a short to ground and the cable
>>> could catch fire. I had a situation where I think there was
>>> a break in the center conductor and arcing occured which led
>>> to the white cable i was using turning black and started
>>> smoking . what I do is just strip the outer layer of
>>> plastic and expose the braid and connect it all together
>>> with the center conductor and leave lots of space between
>>> the 2 cables running out to the coil.
>>> Tesla mailing list
>> Tesla mailing list
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