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RE: [TCML] Where to mount the HV Transformer?Underthe coil orotherwise ?



No problem David , I wish I was half as smart as you on coils or even had
half a green monster. If you want to compare you cable to old coax types it
is closer to RG-17 in size but I have not worked with that big of coax for
about 30 years. I don?t even know the modern equivalent. 


Rich , Kd0zz

As an act of plagiarism . Disclaimer: Any errors in spelling or facts are
transmission errors.



-----Original Message-----
From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
Of David Rieben
Sent: Thursday, June 26, 2008 7:32 PM
To: Tesla Coil Mailing List
Subject: Re: [TCML] Where to mount the HV Transformer?Underthe coil
orotherwise ?

Hi RR, Rich, all,

Yup, y'all got me. I am no "glow bug" amatuer radio operator
as some of you guys are so I do not know the different ratings
of the various grades of coax cable. Anyway, like I was saying,
I actually use the HV transmssion cable from medical x-ray ma-
chines, which is designed just like a coax cable, only much more
robust with about a 7/8" OD and rated at 75 kVDC.

David Rieben



----- Original Message ----- 
From: "stamsund" <stamsund@xxxxxxxxxxxxxx>
To: "Tesla Coil Mailing List" <tesla@xxxxxxxxxx>
Sent: Thursday, June 26, 2008 10:31 AM
Subject: Re: [TCML] Where to mount the HV Transformer?Underthe coil 
orotherwise ?


> RG-8 OR RG-11 has an outside diameter of 0.405 inches vs RG-58 at only 
> 0.195 inches.  I agree that RG-8 or RG-11 would be a better choice.
>
> RR
>
> ----- Original Message ----- 
> From: "Rich Schmuke" <rdj@xxxxxxxxxxxx>
> To: "'Tesla Coil Mailing List'" <tesla@xxxxxxxxxx>
> Sent: Wednesday, June 25, 2008 6:27 PM
> Subject: RE: [TCML] Where to mount the HV Transformer? Underthe 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
> winding.
>
> Rich , Kd0zz
>
> As an act of plagiarism . Disclaimer: Any errors in spelling or facts are
> transmission errors.
>
>
> -----Original Message-----
> From: tesla-bounces@xxxxxxxxxx [mailto:tesla-bounces@xxxxxxxxxx] On Behalf
> Of bartb
> 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
> orotherwise ?
>
> 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?
>
> Take care,
> Bart
>
> 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:
>>>
>>> http://www.pupman.com/safety.htm
>>>
>>> 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.
>>>>
>>>>   Mike
>>>> _______________________________________________
>>>> Tesla mailing list
>>>> Tesla@xxxxxxxxxxxxxx
>>>> http://www.pupman.com/mailman/listinfo/tesla
>>>
>>>
>>>
>>> _______________________________________________
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>>
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