[Elecraft] OT: Feedline Question
Wes Stewart
wes_n7ws at triconet.org
Tue Apr 18 15:57:51 EDT 2017
I'm cursed. It's bad enough that I've worked (I thought) several stations in DX
pileups only to later have the DX say, "Nope, we worked N6WS, not N7WS". Now my
work is attributed to him too. (Just kidding Jim)
Actually, the article never appeared in QST. Too technical; it went right to
the Antenna Compendium. And as a caveat, I never intended the "wet" numbers to
take on mythical properties. Water most definitely negatively affects ladder
lines (or as our European friends say, "chicken ladder line") but it's really
really difficult to quantify with precision.
I never did get around to testing the piece of Wireman line that my friend
Danny, K6MHE, sent me that was covered in moss. Living among Redwood trees is
considerably different from living among Saguaro Cactii.
Wes, the real N7WS
On 4/18/2017 10:37 AM, Jim Brown wrote:
> On Tue,4/18/2017 10:10 AM, Guy Olinger K2AV wrote:
>> Then there is the loss based on number of spacers and loss tangent of the
>> spacer material modifying the lesser air loss.
>
> Below UHF, loss in transmission line is virtually all due to copper losses
> unless the dielectric material is wet or is otherwise made conductive.
>
> Quite a few years ago, N6WS did some excellent work showing that losses in
> window line are greatly increased when it is wet. His work was published in
> QST and later included in Antenna Compendium #6. It should be required reading
> for anyone considering window line. He measured four types of window line and
> some open wire line he built himself. Putting some numbers to it, Wes's
> measurements showed loss at 50 MHz increased from about 0.4 dB/100 ft to more
> almost 6 dB/100 ft when it was wet. The open wire line showed no increased
> loss when wet.
>
> 73, Jim K9YC
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