Thanks guys. I tried the models and they still look poor. Let me
explain a bit...

What is "good" gain?

More than a 3 element yagi.

What frequency?

Well, I was trying 160, 80 and 40. I have a 300ft support at one
point, and a bunch of 100ft trees a good distance away across open
fields (maybe 800 feet).

How high?

Anything up to 300 ft at the feedpoint.

Try this at 10 MHz. Dimensions in feet.

That antenna almost equals a three element yagi in gain, but the 3 ele
yagi has a HPBW of 60 degrees. The V beam has a HPBW of 18 degrees. Not
so good. Even if I try two V beams, one inside the other, I can only
get 3dB more gain.

I was wondering if I was missing something, because I keep hearing
stories about how good big V beams work.