[TowerTalk] Fw: Fw: Why radials improve radiation!

[Rik van Riel]

On 05/23/2011 04:10 PM, pehaire wrote:
> What about an end fed Zepp?  Fed with open wire.  I have read that it thinks
> there is an immaginary 1/4 wave section where the feeder is terminate at a
> dead or insulator point.  I know this is a high impedance point on a zepp.
> A half wave vertical would need no radials  on that resonant frequency.

You may not strictly need radials, but the point of
maximum current is still only 1/4 wavelength above
ground.

This means that:
1) the ground loss due to not having radials is not as
    ridiculously high as that of a 1/4 wave vertical
    without radials, but
2) chances are that you will still notice an improvement
    in signal by adding radials

Personally, I put up a double L antenna for 160m last
december, and plan to add radials over the summer, now
that the weather is nicer.

Without any radials at all, the double L is about 6 dB
below the performance of a 1/4 wave vertical over
perfect ground.

Adding some radials is likely to give me a dB or two.

Adding a near-perfect ground is not an option, or I
would have built a quarter wave vertical to begin with :)

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