[Towertalk] 40m directional antennas

[jljarvis]

>From what I can see, a 2 el 40m yagi will yield 4.5dBd at best,
with a f/b ratio that is well less than 20dB.  Azimuth beamwidth
is on the order of 85 degrees.

By comparison, a 'spitfire' array.... 4 sloping dipoles, folded back
toward the base from the feedpoint, gives 4.5dBd, 20dB f/b, instant
directional change, and substantially reduced cost.  Azumuthal
beamwidth is also in the 85 degree vicinity.  

Has anybody modelled these things?

N2EA