[Elecraft] My Experiences with EH antennas on 20 meters

[Vic Rosenthal]

Charles Greene wrote:
 
> The EH antenna really works, well.  It's efficiency, as an antenna, is on
> the order of 95%, as compared to about 75% for the full size 20 meter
> vertical with elevated radials I build last summer, and few percent for a
> short fat dipole the same size but just loaded with a loading coil because
> of the high losses in the loading coil.

How did you determine this?  Do you know the radiation resistance?  I suspect
the radiation resistance is very, very low...and as a result, so is the
efficiency.

>  On 20 meters, its beam width is on
> the order of a few degrees, concentrated near the horizontal. 

Absolutely not true, unless you have it on your boat over salt water.  The fact
that the antenna does not use the ground as a return path (since it is a
dipole), does NOT imply that the relative power at various angles is not
determined by ground reflections.  In this respect it's no different from the
Cushcraft, Gap, etc. vertical antennas.  

> As it needs
> no ground, its ground losses are very low. It doesn't need a return ground
> path that includes the lossy earth ground.  One of my EH antennas for 20,
> (I have four) has a bandwidth of 200 kHz, and it achieves this without
> resistance or other tricks. 

Well, it has resistance -- the RF resistance of the antenna elements as compared
to the radiation resistance.

> However, the EH antenna beats my
> relatively good Hustler 6BTV in gain consistently by 2 to 3 dB.   

My guess is that the Hustler (for those who aren't familiar with it, it's a
short trap vertical monopole, which needs a ground system) is set up without a
radial system of any kind, or a very rudimentary one.  Am I right?

Vic K2VCO