I have also a question regarding the topic of radiation resistance of short
verticals (with and without tophats) :
All the formulas I saw so far alway assumed the vertical over a perfect
ground.
This means that 'below the earth' there is a perfect mirror of the vertical.
In theory this 'mirror' increases the ERP by 6dB (sometimes know as
'ground-gain') compared to the same antenna without mirror.
But on LF the ground will be far from perfect (and so will be the
'mirror'), unless you are above saltwater or dig miles of radials in your
garden.
So what is the value of this formulas in the real world ?
73, Rik
Rik Strobbe ON7YD
[email protected]
Villadreef 14 B-3128 Baal BELGIUM (JO20IX)
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