[Lf] [Fwd: LF: short vertical dipole]

[Andre Kesteloot]

Rik Strobbe wrote:

> Hello group,
>
> Has anyone ever tried a short vertical dipole on LF (either built and
> tested one or simulated one) ?
>
> The free space radiation resistance of a short vertical dipole would be
> only half of that of a vertical monopole of the same size (Ra =
> 197*H^2/L^2, where H = dipole height and L = wavelength), so that would be
> a 3dB drawback. But close to (a perfect) ground the radiation resistance
> should increase (double) again, and win the 3dB back.
> The main disadvantage would probably the relative low antenna capacitance,
> one would need a large loading coil (= large loss).
> But on the other hand a dipole could be less dependent on
> ground/environement conditions (not as much as a loop but better than a
> vertical monopole).
>
> I have been searching for articles on vertical dipoles on LF, but no
> result. So probably it isn't a good LF antenna, but I'd still like to know
> what it is worth.
>
> 73, Rik  ON7YD