OK, thanks Richard.

How about this.

30 wavelengths per side, average conducting ground, 12 feet above
ground.

What angle do I need for best forward gain, what will the takeoff
angle be at that angle?

If I can get the entire antenna up to 20 feet above ground, how much
better is the performance?

Is there any way for me to do modelling myself without burdening you
or someone with a modeling program? I am not aware of free software
that will model rhombics or vee's.

Thanks,

Art

ky1k at pivot dot net

PS: Some additional info. This is for EME, which does not require much
movement. Since it is so long, it won't be variable in the elevation
angle anyway. But, I hope to move one wire a bit so I can steer the
beam to the left or to the right a little (changing the angle of the
vee at the same time).


Hi Art,

Too many details lacking. 40 to 60 covers too much turf (beyond the
pun), you neglect how wide it will be at the ends too. I ran a couple
of tests to see the gain from 17 to 22dBi and the Z anywhere from 200
Ohms to 2000 Ohms. One thing to consider is the "law of diminishing
returns." The gain for a much smaller V is not much different from
the giant one (think 3dB for each doubling - as a shorthand, I am sure
this fails long before the 20, much less 50th, wavelength is reached).

73's
Richard Clark, KB7QHC



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