I had a WISP unit upgraded for better reception and they used a Yagi
antenna, at least I guess it's a Yagi. Here's a photo.

http://www.netwifiworks.com/images/a.../Yagi/yagi.png

This doesn't seem to fit the mold in a couple of ways. The elements are
not spaced at all regularly. The spacing seems to vary around a bit.
But more importantly, I've read that the director elements are
*insulated* from the support beam while these are all welded. Obviously
it works. I'm getting about 6 dB stronger signal than before although
it's a bit hard to compare as the location changed and I measured about
a 3 dB gain with the old unit in that location.

But more importantly, with the signal rising by 6 dB, the reported
background noise also rose 6 dB. Isn't SNR what is important that the
antenna should have improved?

This Yagi claims something like 20 or 25 degree beam while the old
antenna had a 60 degree beam.

--

Rick C