[TowerTalk] Modeling a ground plane

[Jim Brown]

On Wed,9/10/2014 8:11 AM, Bill Turner wrote:
> I'm curious why this is.

Time spent on N6LF's website will yield great rewards. He's done 
extensive research on radial systems for 160M and HF verticals.

http://www.antennasbyn6lf.com/

A good starting place is his QEX article on elevated radial systems.

Also -- several years ago, I hung two sloping vertical wires off of 
either side of my 120 ft tower (insulated at the top) and fed them at 
the bottom against four radials elevated about 6 ft. The antennas had 
the directivity that NEC predicted (roughly 6 dB F/B in the direction of 
the slope), but not the gain. A while later, I chatted with N6BT about 
this, and he said that they were too low, and that 18 ft was a minimum 
height for 160M. I raised them (gull-wing style) and the gain improved a 
bit. Don't ask me how much they improved -- that's VERY difficult to 
measure. :)

73, Jim K9YC