[Elecraft] Beam antenna question

[Ron D'Eau Claire]

Any horizontally-polarized antenna needs to be at least 1/2 wavelength above
ground for optimum performance, e.g. 32 feet up on 20 meters, 16 feet up on
10 meters. 

They will work at lower heights of course, but at reduced gain as they are
lower. 

20 feet sounds like a reasonable compromise for a 14 MHz and up antenna,
especially since the actual apparent ground is usually somewhat below the
surface of the earth in most locations.

73, Ron AC7AC  

-----Original Message-----

I have also read they only need to be up about 20 feet high. 
Rich, n0ce