Irv Finkleman wrote:
Why not run two ground wires in parallel -- one twice as long as the
other? When one is Hi-Z the other will be Lo-Z and vice versa.

That will help on some frequencies but it is akin to trying to
erect a 1/2WL fan dipole for all frequencies - can't be done. Sooner
or later, you will run into a frequency where length #1 is N*1/4WL
and length #2 is (N+1)1/4WL. "It's not nice to fool Mother Nature."
--
73, Cecil http://www.qsl.net/w5dxp