[Antennas] Radial Formula

Terry Conboy n6ry at arrl.net
Fri Oct 3 14:02:05 EDT 2008


At 10:29 AM 2008-10-03, Deon Erwin ZS1ZL wrote:
>I have two questions about calculating the length of radials.
>
>*  Which formula is used for calculating the length of 1/4 wave elevated
>radials: 300/f or 246/f ?
>
>*  Which formula is used for calculating the length of 1/4 wave ground
>mounted radials (laid on the ground): 300/f or 246/f ?

Elevated radials are probably closer to 234/f (in feet).  The actual 
value varies somewhat with wire insulation, the number of radials, and height.

On-ground or buried radials resonate with somewhere around 80% of the 
elevated radial length, although the resonance is extremely broad due 
to the losses in the soil.

Rudy, N6LF has excellent new experimental info on radial systems at 
<http://www.antennasbyn6lf.com/>http://www.antennasbyn6lf.com/ that 
is well worth reading.

73, Terry N6RY 



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