[TowerTalk] Phased vertical elevated radial configuration

[Jim Brown]

On 9/7/2012 7:51 PM, Chuck Gerarden wrote:
> I have read in ON4UN's book
> that the radials should be offset from each other and not connected
> between each vertical. Can any one confirm this?

As it happens, I have a similar installation here -- a 115 ft tower with 
sloping wires insulated from the tower and fed from the bottom against 
four elevated radials for each vertical. I feed one or the other, but 
not both. NEC shows some interaction between them, which I am 
controlling by shorting the feedline of the unused antenna in the shack, 
making the feedline a shorted stub. LOTS of NEC modeling went into this. 
:)  The radials are installed as ON4UN recommends -- no connection 
between the two verticals.

My radials are elevated about 16-18 ft (3 ft at the feedpoint, rising 
gull-wing style as the leave the feedpoint). I originally installed them 
at about 4 ft, and the efficiency was poor. This summer I raised them 
and the efficiency seems better. Since the tower is a passive reflector 
(thanks to a SteppIR and a 22 ft 2M Yagi on an 8 ft mast on top), I have 
eight on-ground radials on it, and may add more. The tower and its 
radials are grounded, the elevated radials are not.

73, Jim K9YC