Re: HV Cables

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Brent De Bolt" <pikmicrotools-at-msn-dot-com> 

Hello all;

The question of which H.V cable to use.  I've always recieved the best 
advice (for the area I happen to be in, when working away from home) from 
any major local neon sign company.  They know the local suppliers inventory 
of HV cable...and most of the people you talk with will usually give you 
,not only advice, but samples of the cable they use. Also talk to 'rewind 
shops'. There is a motor rewind shop here (Mac and Mac Electric. 
Bellingham, Washington) that are a tremendous help when I need small 
amounts of glass tape to insulate connections, or HV dopants. They have 
gone as far as to dip my home built transformers and coils for me. It sure 
beats buying 55 gallon drums of dopant to HV insulate and prevent the 
offensive corona that leeches power from the coil and circuit assemblies.
I've found that most of the rewind employees have a curiosity about what I 
am building so that not only do I get the information I need from them, 
some of the older people working there have excellant ideas for refining my 
projects.

----- Original Message -----
From: Tesla list
Sent: Sunday, November 09, 2003 6:49 AM
To: tesla-at-pupman-dot-com
Subject: HV Cables

Original poster: "Ian McLean" <ianmm-at-optusnet-dot-com.au>

Hi all,

I am wondering what is the general consensus out there amongst coilers as to
what makes the best cable for HV.

For some time, I have been using RG-8 coaxial (Thick Ethernet), with the
outer braided shield removed.  This has excellent dialectric strength and is
rated for more than 35kV.  I believe it is, or has been in the past, been
widely used as HV transmission cable?  I managed to get a reasonable length
of used cable from an ex-employee when they moved their building trunk cable
over from this to fibre.

However, the thick, heavy, yellow RG-8 coax is becoming very difficult to
obtain and expensive, and I am wondering about alternatives.  I have looked
through Tesla archives, I did not find much, except that someone mentioned
the use of RG213 coaxial, but according to the spec's, this cable is only
rated for 3.7kV RMS.  It is also not solid core, but multi-stranded.

I have been toying with two ideas:
1) Just buy some Neon cable.
2) Using thick guage enamelled copper, with my own insulation around it (a
few layers of heatshrink maybe).

I believe, from my research, that for HV, esp. at relatively low current,
solid copper conductors are best (comments welcomed).  I have tried
multi-stranded copper (high current DC) before for 15kV-at-60mA (NST ouput),
but the HV tends to "buzz" inside the cable, and you lose most of the power
to what I believe must be coronal losses within the strands of the cable.

I am sure this is an old topic, so I apologise for that.

All commented welcomed.

Rgs
Ian