Behold, Dale Parfitt signalled from keyed 4-1000A filament:

Antenna theory, and NEC modeling radically disagree with this- How
many
antennas do you want to see that are not 1/2 wave above a perfect
ground and yet show outstanding directionality?

W4OP

Phased arrays can be made directional. We are talking longwires here.

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca