[Elecraft] What your mother didn't tell you about transmission lines

[Bill W4ZV]

Fred Townsend wrote:
> 
> Rubber (parallel) lamp cord can be used as transmission line and it is
> cheap. Z0 runs 95 to 120 Ohms depending on insulation thickness.
> 

True, but it has very high loss (especially at higher frequencies) and
should only be considered as a last resort.  About 10 years ago ET3PMW was
attempting to get on the low bands and only had zip cord available for
transmission line.  I thought it should work fine for 80 and 160.  However,
on 80m running 100 watts he was barely detectible here using a 1200'
Beverage for receive.  Once Paul got some good ladder line, his signal was
typically S8 on 80m and S6 on Topband, where he made several hundred QSOs
with North America even in summer QRN (June/July).

There is a loss graph on page 2 below but I believe ET3PMW's losses were
much higher.  Of course this could have been due to poor quality wire
available in Ethiopia.

http://www.we0h.us/Amateur_Radio_stuff/Antenna/ZIP-Cord-Antenna/Zipcord-Antenna-7903031.pdf

73,  Bill


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