Topband: Open wire line vs. Paralleled coaxials.

[Jim Brown]

On Thu, 5 Nov 2009 06:41:47 -0800 (PST), Dennis OConnor wrote:

>I have runs of coax out to a 1000 feet that on 80 meters and to 
>1500 feet on 160 meters

There is plenty of published data for the loss in coax. In general, 
it increases with wire resistance (skin effect), which is 
aproximately the square root of frequency. While the loss in coax is 
small on 160M, it is not zero, and 1000 ft of Belden 8237 (RG8A) 
will cost you 2.3dB. On 80M it will cost 3.3dB. No big deal on a 
receive antenna, but I sure wouldn't want it on TX! 

Good references are the Belden catalog (online), the ARRL Handbook, 
and the ARRL Antenna Book. 

73,

Jim K9YC