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Random Wire Antenna


Ronald Morrison
 

Just because an antenna can be matched doesn't mean that it is a good radiator.  For one thing, the radiation pattern gets very complex at higher freq.  Height above ground has a major impact on the vertical angle of radiation, etc.  Also, you have high loss in the coax due to the high SWR on it.  A single counterpoise will have the same problem with a reactive impedance as the "random wire" has, so it is best to have at least one 1/4 wave radial for each band. In addition, radials are lossy on the ground.  Even one foot above ground is more efficient.

Ron, K5DUZ

On Sunday, June 14, 2020, 01:35:40 PM CDT, Darryl J Kelly <kk5ib01@...> wrote:


I have a 70' end fed wire, 10' at feed end up to a tree at 25', last
20' sloping down, 9:1 unun, 50' of coax on ground, 26' counterpoise
sloping down to and on ground. High SWR 6.7 at 6 meters, most much
lower, high impedance 110, also most much lower. Tuneable on 80
through 6 meters with LDG AT-200 Pro II tuner. I have very good SWR
measurements with different random lengths from 40' to 115'. Just my
experience.
Darryl, KK5IB




Darryl J Kelly
 

I have a 70' end fed wire, 10' at feed end up to a tree at 25', last
20' sloping down, 9:1 unun, 50' of coax on ground, 26' counterpoise
sloping down to and on ground. High SWR 6.7 at 6 meters, most much
lower, high impedance 110, also most much lower. Tuneable on 80
through 6 meters with LDG AT-200 Pro II tuner. I have very good SWR
measurements with different random lengths from 40' to 115'. Just my
experience.
Darryl, KK5IB