On Wed, 07 Jul 2004 19:16:36 -0400, Albert wrote:

OK, thanks Richard.

How about this.

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

You still don't say how far apart the tips are.

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

The angles were pretty consistant at 5 degrees at 12 feet up. Gain
did not vary much either (5dB is a lot perhaps, but then there are so
many variables to consider).

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

Height change up doesn't seem to be signficant.

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

Hi Art,

With monster size antennas and a desire for accuracy, this drives the
model towards a lot of segments ($$$). You could use the free version
of EZNEC but it will blow up.

EME hmmm? Major lobe is 5 degrees off the horizon and 5 degrees wide.
Isn't there a problem with an antenna looking at the moon so close to
the horizon (ground temperature)? Also, the moon will only fill that
box for, what, 15 minutes?

You might find it simpler to build an array of dipoles such that they
were all looking up at the same box. Combining them may be a bitch
however, so I can see your desire for simplicity here.

73's
Richard Clark, KB7QHC