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HV coax?
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From: Bill the arcstarter [SMTP:arcstarter-at-hotmail-dot-com]
Sent: Monday, May 11, 1998 10:29 AM
To: tesla-at-pupman-dot-com; dr.resonance-at-next-wave-dot-net
Subject: HV coax?
It was written:
>>From: D.C. Cox [SMTP:DR.RESONANCE-at-next-wave-dot-net]
>>Sent: Friday, May 08, 1998 8:51 PM
>>To: Tesla List
>>Subject: Re: Pole pig HV wires (fwd)
>>
>>to: Brian
>>
>>Never use coax to transmit power from a pole pig to a Tesla
oscillator.
>>It's capacitance is just right to resonate with the secondary of the
>>xmfr
>>and will produce severe overvoltages on the order of 150 kV. Best to
>>use a
>>single conductor wire such as spark plug wire or coax can be used if
>the
>>outer ground braid is stripped away and not used at all. Ground one
of
Can you go into more detail on this?? Is this a resonance between the
cable and the xfmr, or is it s transmission line phenomenon??
Seems like the output impedance of a pig would be much less inductive
than that of an internally-current-limited NST. Thus this resonance
would be less pronounced on the pig. Am I deluding myself?
Recently we've been powering our coil remotely via two parallel 30 ft
lengths of 100KV-rated x-ray coax hooked to the pig. This stuff is
nearly an inch o.d., and the insulation between the center lead and the
outer ground is at least 1/4 inch. We do notice some odd effects - such
as thin wispy arcs off the far end of the cable... We have the shield
grounds attached to the frame of the pig (ground) on one end only.
BTW- modern commercial x-ray transfomers have a special circuit designed
to dissipate the energy capacitively stored in the cable after the
exposure is complete. This is to prevent accidentally electrocuting the
field service engineers...
Is the above resonance effect the "Blum Line" effect (which I've tried
to research but can't find anywhere...)??
Thanks for your assistance!
-Bill the arcstarter
Starting arcs in Cinci, OH
http://www.geocities-dot-com/CapeCanaveral/Hangar/6160
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