Topband: elevated radials

[Joe Subich, W4TV]

Bill writes: 

> The gist of the article was  four elevated radials over average 
> ground at 65 feet played just about the same as a 60 radial buried 
> system.  I don't have the particulars and my 

That's about right for an 80 meter system.  

The N7CL work that N4HY and N2EA reference indicates that elevating 
the "ground plane" 1/4 wave above ground gets the coupling into the 
soil down to insignificant levels (3/8 wave to immeasurable).  At 
heights approaching 1/4 wave, one could reasonably expect free 
space performance out of a ground plane antenna if the feedline is 
properly decoupled.  N7CL's work is well worth reading ... it was 
done for the military (if I recall correctly) and his summaries on 
the reflector was the highlights of a very large study. 

The real "take away" of Eric's work is to validate work by W8JI, 
ON4UN and others that elevated radials at low heights (certainly 
less than 1/8 wave) require a good in or on ground system for 
best performance.  For example, ON4UN used a single elevated radial 
on each verticals in one of his early 80 meter 4-square arrays but 
that array sat directly over his 160 meter ground system which 
consisted of 250 radials from 65 to 200 feet long. 

73, 

   ... Joe, W4TV