Vent rotor motors work very well. These motors are used in HVAC systems in
commercial buildings. They usually take 24 volts to operate and only turn
from 0 to a few degrees past 90. Most are settable.

--jj
"Richard" wrote in message
...
Hi. Has anyone designed a way to mechanically rotate their VHF/UHF yagi so
that it can be either horizontally or vertically polarized? If so, can
you
please direct me to a website or whatever. Preference right now for a
manual system, but would also take a look at motorised systems.

TIA.

Rich.

(Followup set to rec.radio.amateur.antenna, so all replies will go to this
group).