[TCML] New Coil Questions, David and x-ray cable

Sat May 30 08:23:11 MDT 2009

Hi Jim,

Well, my run from my control panel to my tank
circuit is approximately ~50 ft. and I simply use
a single cable, using the inner conductors as the
"hot" and the outer braided shielding as the re-
turn. If you're wanting to build a 24" secondary
coiled monster, I don't think I'd want my trans-
mission line to be a whole lot shorter than that,
as that would start getting you uncomfortably
close to the "strike" zone. :^0 I'll check and
see if I have a shorter piece with both of the
Federal male end plugs intact, though. Incident-
ly, just how short are you wanting it?

David

----- Original Message ----- 
From: "Jim Mora" <wavetuner at gmail.com>
To: "'Tesla Coil Mailing List'" <tesla at pupman.com>
Sent: Friday, May 29, 2009 7:16 PM
Subject: RE: [TCML] New Coil Questions, David and x-ray cable

> Hi David,
>
> I am nearing first light of my 14400/7.5kva coil. I have gone so far at to
> install standard Federal females at the HV cabinet and at the coil. I 
> really
> want to run the x-ray cable in tact for clean, safe, quick connect/
> disconnect (power off).
>
> In light of Dr. Resonance's warning of HV voltage rise at 60 hz I have
> installed a 18KV lightning utility MOV at the cabinet from HV to ground 
> and
> a horn gap across the ASRG gap. Unfortunately, my feeder cable is an
> excessive 60ft, so there is a lot of collective capacitance. Have you run 
> a
> shielded cable that long? Would you consider parting with a shorter one? 
> You
> are running higher power than I am at this point. I want to wind a 22-24"
> Sonotube next...that will outgrow my back yard but not my desire for more
> power and longer streamers!
>
> Thanks,
> Jim Mora
>
> -----Original Message-----
> From: tesla-bounces at pupman.com [mailto:tesla-bounces at pupman.com] On Behalf
> Of David Rieben
> Sent: Friday, May 29, 2009 6:07 AM
> To: Tesla Coil Mailing List
> Subject: Re: [TCML] New Coil Questions
>
> Hi Tyler,
>
> I think others have already addressed your questions
> here but I will just add this little bit about x-ray cable.
> High voltage x-ray cables are the lines used to trans-
> fer the HVDC and the low filament voltage from the
> high voltage transformer supply to the x-ray tube head.
> They usually consist of two or three individually insu-
> lated (for low voltage) wires (usually around #14 or #
> 16 braided conductor) in the center. This conductor
> bundle is wrapped with a thick layer of rubber insulation,
> which is for the high voltage standoff. Around the out-
> side of this thick rubber sheathing is usually a wrap of
> carbonized semiconductor tape and around the tape is
> a metal braided sheating, which is connected to ground.
> Finally, around the outside of the metal braiding is a
> thin rubber outer protective sleave. Finally, the end
> terminations are usually a special male plug end that
> fits into the female receptacle ports of the HV transfor-
> mer and the x-ray tube heads. Here is a picture of
> several rolls of x-ray cable that I recently aquired:
> http://www.flickr.com/photos/33464569@N05/3408614009/
>
> David Rieben
>
>
> ----- Original Message ----- 
> From: "Tyler Pauly" <rpggod714 at yahoo.com>
> To: "Tesla Coil Mailing List" <tesla at pupman.com>
> Sent: Wednesday, May 27, 2009 10:20 PM
> Subject: Re: [TCML] New Coil Questions
>
>
>>
>> I have more questions on the following two.
>>
>>> 7)  Can I wire an arc welder in series with my outlet leads to current
>>> limit?  I would think so, but again, it doesn't hurt to ask.
>>
>> Yes, a 225 amp stick welder with its 240 input leads in
>> series with the input leads to the pig can be used as a ballast.
>> Many people that go this route simply short the output welding
>> leads and use the amp selector switch for input current control.
>> However, as Scot has also already mentioned here, most arc
>> welders are made as cheaply as can be gotten away with and
>> typically have like a 20% duty cycle at their maximum setting.
>> I finally ended up making a homemade ballast from the core
>> of a defunct x-ray transformer. You would have to make sure
>> that your core has sufficient cross sectional area to handle the
>> power that you're looking to control, too. Others can comment
>> on formulae for this.
>>
>>
>> I've heard of people using a PVC pipe as a form to wind heavy wire 
>> around,
>
>> and sticking welding rods inside to form an inductive ballast.  This
>> sounds somewhat cheap and very easy, but will it work?  What could go
>> wrong, what should I take into account etc.?
>>
>>
>>
>>> 8)  My pig only has 1 HV bushing, so should I just split the wiring I
>>> attach to it to get 2 leads off of it to make the primary circuit? 
>>> Sorry
>
>>> for the bad wording, I hope I get my question across.
>>
>> I also use a "single eared" pig to drive my current big coil with
>> out any problems. I isolate the case "return" of the pig as RF
>> ground and do not allow it to be attached to mains ground so
>> that the nasty RF kickbacks don't end up on the metal
>> surfaces of my control panel and bite me. ;^0 "I" use
>> that high voltage rated x-ray cable to run the HV from my
>> pig to my tank circuit and hook the single output bushing of
>> the pig to the inner conductors of the cable and the outer tank
>> to the outer braiding of the cable. This cable is basically coaxi-
>> al cable on steroids and is generally rated at around 75 kVDC.
>>
>>
>> I'm a little confused on both responses to this question.  For your
>> answer, where do I get some of this cable?   And what is the second 
>> object
>
>> I'm connecting the cable to?  I'm not very familiar with the lingo used
>> with pigs.
>> So does this cable have two insulated conductors inside?  If I were to 
>> use
>
>> normal cable with only one conductor, I would be connecting an end to the
>> bushing and the other end to.... what again?   =P
>>
>> Thanks again!
>>
>> Tyler
>>
>>
>>
>>
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>
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