[Elecraft] Long wire antennas MORE

[K9MA]

On 1/13/2018 07:44, Don Wilhelm wrote:
> All information I have seen says that the counterpoise needed for an 
> EFHW is 0.05 wavelength - at 40 meters, that is about 3.5 feet.
>
> If you make it longer than that, it becomes an offset center fed 
> antenna, longer than a halfwave, in other words, it is a random length 
> wire.  Both the half wavelength wire and the counterpoise wire will 
> radiate. 

True, and the longer the counterpoise, the more it will radiate, right 
into the ground if it's just lying on the ground, so there's really no 
point in a longer counterpoise for the EFHW.

One extreme case is the center-fed full wave, or "two half waves in 
phase".  It has the high feedpoint impedance of the EFHW (actually about 
double) and has a pattern much like a dipole, but sharper.  It has a 
couple dB of gain over a dipole broadside but, of course, less gain in 
other directions.

73,

Scott K9MA

-- 
Scott  K9MA

k9ma at sdellington.us