Their web page is at
http://www.steppir.com/
they have range of beams and verticals that are tunable accross the range. On
beams they do not change element spacing, but there is enough range to
maintaing good pattern and gain. Many users love them, they are weather
resistant. The idea is that they use metallic tape inside of fiberglass tubing
and motion is done by stepping motors, which are very reliable.

They are tunable to particular frequencies, so they are not "broadband" like LP
arrays, but they beat LP in performance on any frequency withing the range.

73 Yuri


I find your comment very interesting. I was totally unaware that the
IR
antenna had laterally moveable elements so it can compete with
monobanders.
Can you point me to a URL that shows how the elements are moved along
the boom?
I suspect that such a design would provide spread spectrum coverage
since it would be resonant on all frequencies.

Regards
Art