Ian White, G3SEK wrote:
"It also works, roughly for shorter radials."

Yes. .05 times the length along radials spaced at 3-degrees gives the
approximate distance distance between them at any point. It doesn`t have
to be between tips, just the same distance from the tower on both
adjacent radials.

Ed Laport says more and longer radials is better, but there is a point
of diminishing returns which occurs at 1/2-wavelength.

I`ve seen other reports that radial wire is better used when cut into
more and shorter radials.

The FCC`s 120 radials of 1/4-wavelength has been efficient for medium
waves in thousands of instances in all types of soil. It`s overkill in
highly conductive soil, but regulations must be somewhat uniform for
satisfactory enforcement. FCC`s rule is based on B,L,& E`s research. As
I recall, B, L, & E worked at 3 MHz.

Best regards, Richard Harrison, KB5WZI