[TowerTalk] Coax Loss -- RG-Numbers Don't Tell us Much

[Rick Karlquist]

Jim Brown wrote:
> On Thu, 4 Feb 2010 10:38:19 -0800, Rick Karlquist wrote:
>
> Rick,
>
> My point is that virtually all transmission line losses at HF are I
> squared R

That is not in dispute, but what is in dispute is the
assumed proportionality of R to the square root of frequency.
A copper plated aluminum cable that is better than an all
copper cable at 50 MHz may not be better at 1.8 MHz.
But the DC resistances will be yet another set of numbers.
Hard to generalize.

Look at some examples in the Belden catalog:

7977A and 8214 have the same DC resistance but 2:1 RF loss ratio
8237 and 7809 have the same RF loss but 1.5:1 DC resistance ratio
(RF loss at 50 MHz).

Rick N6RK