[Elecraft] AX1 Loaded Whip Antenna - Elevation and

Jim Brown jim at audiosystemsgroup.com
Tue Aug 27 16:21:01 EDT 2019


Dave's observation is about how the antenna actually works, as 
determined by Mother Nature, and, depending how the antenna is rigged, 
he's probably right. Antennas work by carrying RF current, any end fed 
radiator needs a counterpoise, which, because it's carrying the same RF 
current as the end fed radiator, CAN ALSO RADIATE. Indeed, this antenna, 
depending on how it's deployed, can be thought of as an off-center fed 
dipole.

Back when I lived in Chicago, I had another "ad hoc" antenna that was 
effective on 80 and 160M. My shack was on the second floor, the antenna 
was a loaded resonant dipole tuned to 80 and 40 that sort of worked on 
30 and 15, and was fed by vintage 75 ohm Belden "kilowatt twin lead." To 
use it on 160M, I ran two wires down to both sides of a wrought iron 
fence that ran around my front yard (both sides because it was broken by 
a gate). The wire and the fence functioned as a counterpoise, and the 
vertical wires radiated (and modified the resonance). As it turned out, 
that antenna loaded that way worked better on 80 than it did loaded as 
dipole, simply because the dipole wasn't very high (35-40 ft). I'm 
reminded that my buddy KK9H used the air conditioning ducts in his home 
as a counterpoise on 160M. We've worked several times since I moved to W6.

There are photos and a description of my Chicago antenna weedpatch 
(won't dignify it by calling it an antenna farm) in

http://k9yc.com/LimitedSpaceAntennasPPT.pdf

73, Jim K9YC

On 8/27/2019 12:38 PM, Grant Youngman wrote:
> But I fail to see the rationale of using the AX1 as a “counterpoise”.
> For quick low profile portable, the AX1 works as well as you can expect a very short loaded radiator to work.  For that purpose it’s easy, quick on the air, and does fine.



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