I've done a lot of comparison testing. First of all, a half wave
vertical is not very much different in performance from a quarter
wave vertical. And a half wave vertical fed at the bottom is
very little different than the same half wave fed as a "vertical
dipole" in the center. Having said that, the comparison comes
down to vertical vs horizontal. On 40M, at my QTH with high ground
conductivity, a vertical is indistinguishable from any dipole up
to a wavelength high. (Except for local signals which are much
better on any dipole). Others have reported different results.
On 20M, at times a vertical will beat a dipole and other times the
dipole will beat the vertical. There does not seem to be a clear
cut winner in the long run. If you can only have one, then
put up whatever is the easiest for your situation. A really high
dipole on 20M will be much better than a vertical on the ground
when propagation favors low angles, when the stack owners switch
to their top Yagi. I observed this with a dipole at 110 feet.
But this is not the usual case.
One other disclaimer: I am assuming the vertical dipole is near
the ground. Mounting a vertical on a tower doesn't work very
well if you model it. I've never tried a vertical at a significant
height.
Note that on receive, a dipole is nearly always quieter than a
vertical on 40M. This doesn't seem to be as much of an issue
on 20M.
Rick N6RK
fraz1 wrote:
> Hey folks....
>
> I am very familiar with the "models". Does anyone have hands-on A/B
> experience with these two antennas that can share their actual findings?
> I'm talking in the 40M-20M range.
>
> 73 John K4NP
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