[TowerTalk] 160m vertical and the number of radials

[Jim Brown]

On 12/2/2022 12:21 PM, Pete Smith N4ZR wrote:
> I just added 5 more radials to the 13 I had originally under my inverted 
> L, and the R dropped from 34 to 31 ohms. Barely still worth doing, I guess.

It all depends on the difficulty/cost of adding more. The radiation 
resistance of a vertical, which represents radiated power, is a function 
of the vertical height, not the total length. There's a graph of this in 
my tutorial. The combination of radiation resistance and ground loss, 
both in Ohms, forms a voltage divider for the transmitter current, and 
power lost is 10 log of the divider ratio. If, for example, you have 
50-60 ft vertical, radiation resistance is likely to be less than 8 ohms.

73, Jim K9YC