My point was that any properly tuned unnamed generic quad should be a
better-performing antenna than a Spiderbeam. However the usual HF quad
free space NEC calculations for both:
Spiderbeam (from
www.spiderbeam.net)
20: 6.7 dBi gain
15: 6.9 dBi gain
10: 7.1 dBi gain
full-size 2 el quad (from
www.cebik.com)
6.8-7.2 dBi (at freq where f/B is peak, also depends on boom length)
I'd say in practice they are pretty much equal...the quad being three-
dimensional will be much harder for one or two people person to put up.
Tor
N4OGW