[TowerTalk] Topband: Radials on ground v FCP

[Jim Brown]

On 1/11/2022 1:15 PM, Lux, Jim wrote:
>> N6BT, who has done a LOT of work on the topic of elevated radials, 
>> told me that 20 ft is a minimum height for 160M. When I raised mine 
>> from about 6 ft to that height, TX signal improved significantly. 
> 
> 
> But what is the *reason* for it working better.  Is it something as 
> simple as "the currents in the radials aren't loaded as heavily by 
> something 20 feet away as opposed to 6 feet away" in which case it's a 
> sort of soft transition, and "going higher" is a matter of diminishing 
> returns.

Loss coupled from the earth under them, and, as Rudy observed in the 
study below referenced by Wes, unequal current distribution between 
them. I suspect differences between his advice and Rudy's with respect 
to height are the result of differences in soil conductivity. Mine is poor.

On 1/11/2022 1:55 PM, Wes wrote:
 > Additionally see: "A Closer Look at Vertical Antennas With Elevated
 > Ground Systems" by Rudy Severns N6LF.  He recommends 10-12 elevated
 > radials as a minimum.

Yes, and for very good reasons. In my dense woods, it's tough enough 
keeping four in the air, what with stuff falling on them every few 
months. And at 80, I don't get around as well as I used to. :)

73, Jim K9YC