Cecil Moore writes:

John Ferrell wrote:
An antenna still works best at its resonant frequency. (best is in
the eye of the beholder!)

"Works best" needs a definition. An Extended Double Zepp
is not resonant but "works better" than a resonant dipole
by about 3 dB broadside.

Once it's up, you can't rotate it. Whether the gain and the nulls are
a net advantage or not depends on the application.

73
LA4RT Jon