There have been several tilt a boom designs. The first was thje W4GL all
driven arrays back in the 50's with tilt a boom design. W4GL may have a lock
on the name at the time. Hy-gain used a tilt a boom design at one time in
the early Thunderbird beams. The design was fairly simple just use the
proper hardware for the boom to mast u bolts so that the boom portion tilted
the boom away from the mast so the elements pointed straight up rather than
horizontal.
Wingard the windmill tower people (the owner was a ham listed or shown in
their ads for a time) used a rotary adapter gear so you could tilt the
antennas at the top. The towers are still standing at most airports in
North America.
We put up a T joint on a telephone pole so you could turn the antennas
upside down to remove. We found with bigger antennas that it was best to
not turn the T but we had a guy stand on top ot the telephone pole a guide
the antenna into the open of the T. The T did double duty as a sleeve
bearing and the rotor was mounted on another T below this. Look in the old
ARRL handbooks and antenna books from the late 50's (the original article
was in a 1956 QST.).
73 Dave K4JRB
List Sponsor: ChampionRadio.com - Trylon self-supporting towers,
safety equipment, rigging gear, LOOS tension guages & more!
http://www.championradio.com
-----
FAQ on WWW: http://www.contesting.com/FAQ/towertalk
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
|