Actually, maybe it doesn't have gain compared to a halo... I'm not
really sure... I have an inconclusive 6m Big Wheel EZNEC model with an
average gain problem... though at this point it's only showing a -0.5dB
average gain or so, and impedance and gain seem constant with
segmentation changes, so it's probably not so bad.
I made it back when I was considering building one and modified it a
little bit to make the avg. gain work out better.
Anyway, if anyone wants to try to get it to work reliably, there's a
model at
http://www.n3ox.net/projects/eznec/6mBigWheel.ez
Dan