Re: HV Cables

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

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, November 10, 2003 5:04 PM
Subject: Re: HV Cables


 > Original poster: Tesla729-at-cs-dot-com
 >
 > In a message dated 11/9/03 12:09:21 PM Pacific Standard Time,
 > tesla-at-pupman-dot-com writes:
 > >However, for higher voltage applications, the best high voltage wire out
 > >there is type RCB wire made by
  <snip>
 > >Dan
 >
 >
 > Hi Dan,
 > all,
 >
 > Yep, sounds like some great stuff but probably most of us can't
 > afford such exotic cable. Another suitable alternative is the trans-
 > mission cables that run the HV from the HV ports of x-ray transformers
 > to the x-ray tube heads. This cable is made just like coax cable that
 > plugs into the back of your TV from the cable or satellite compa-
 > ny, only a lot bigger.

Not even close...just to discourage folks from using Cable TV coax, which is
usually foam dielectric RG-59 or RG-6 coax.  They use foam to reduce the
loss, particularly at GHz frequencies (i.e. the output of the LNB on the
satellite dish which is around 1 GHz).  Foam dielectric + HV = bad news...




It actually has 3 central conductors w/ low
 > voltage insulation from each other and these (3) 14 AWG? con-
 > ductors are wrapped w/ thick rubber insulation which is in turn
 > wrapped in some carbon simi-conductor tape, then tinned-braided
 > grounding sheath and finally a thin outer rubber sheathing.

That semiconductive layer is the key to quality HV cable.


 > The whole
 > cable is about 7/8" in diameter and is rated at 75 kVDC. X-ray cables
 > would be quite expensive theirselves, too, but it can often be found on
 > ebay in relatively short lengths (10' to 20') under headings like "high
volt-
 > age". It may come w/ the blue Federal male plugs on each end made to
 > fit the female Federal HV ports of the x-ray transformer or x-ray tube
 > but they can easily be cut off if need be.
 >