I used an antenna quite similar to this (mine had only one ground reflector)
for local (within 300 miles) 40 meter ssb. Mine was at about 16' high.
About 1/8 wl on 40. It was consistently 2-3 s units better than the the high
(70') 40 meter dipole when working stations within about 300 miles. 300-1000
miles they were very close. For DX the high dipole was always better.
Here's a good web site that explains the phenomema
http://www.athensarc.org/nvis.htm
"William Taylor" wrote in message
...
http://www.hamuniverse.com/supernvis.html
The claim is that a dipole 7 feet off the ground has
a 10db gain over a G5RV at 50 feet.
Is that possible, or hype?