[TowerTalk] More Interference Pattern

[Leeson]

Around 1961, as a grad student working for O. G. "Mike" Villard, W6QYT, 
I was engaged to design and build a transistor/diode switching unit that 
ran a bunch of vertical antennas in a line, aimed at WWV Colorado. This 
created the equivalent of a moving antenna, and the audio-frequency 
Doppler shift of one-hop, two-hop and three-hop signals, seen in an 
audio spectrum analyzer, was a measure of the angle of arrival of each.

How times have changed!

Dave, W6NL/HC8L