[Antennas] Radial Systems: Wires, optimum number and length

[Edward Dickinson, III]

While the topic of radials is about, please note that optimum ground radial
length for a quarter-wave verticals is proportional to the number of
radials.

>From The ARRL Antenna Book, 17th Edition, page 3-13

Table 3
Optimum Ground-System Configurations

Number of radials 	16	24	36	60	90	120
Length in wavelength	0.1	0.125	0.15	0.2	0.25	0.4
Power loss @ low angle	3db	2db	1.5	1	0.5	0
(reference)
Feed-point impedance	52	46	53	40	37	35

Using 1/4 wavelength long radials when there are less than 90 of them is
ineffectual.	


Best regards,
Dick - KA5KKT