I don't have pictures of cranking up the mast, but the crummy
winch made it a dicey process and I'll settle for just getting it up
there. Here the OB2-40 is at it's final height and the mast is
mounted in the rotator. Notice how little sag there is in the
elements, which are about 49 feet long tip to tip. This is a
really strong antenna.
I had no idea, though, that this antenna would get tested so severely
so soon after I put it up. We get strong wind gusts here in
Arizona during the springtime, but this year it has been especially a
problem. I have a reasonably accurate wind gauge on a pole above
my house (about thirty feet above the ground in total), and several
times over the next few days I measured peak gusts over 90 miles per
hour. Gusts over 70 miles per hours were too numerous to keep
track of. The OB2-40 survived in fine shape, but it was simply
awful to have to watch the beating it took. The deflection of the
elements in the picture below is all horizontal ... that isn't element
OK, then ... on to the tribander. The boom comes in four
sections, and gets spliced together in the same fashion as I described
for the OB2-40. I rigged a couple of boards to support the 30'
long boom and started assembling the elements. Here you can see
the sixteen element-to-boom clamps mounted in position, all of which by
the way are clearly marked on the boom by OptiBeam. The
insulators come preattached to the saddles, and it would be pretty
difficult to mess up the rest of the assembly.
The phasing line between the driven elements requires rather precise
spacing, so I followed the manual's suggestion and pre-assembled those
portions (with the balun) before attaching them to the boom as one
piece. These are the driven element center sections, which are
shipped with the center insulator already in place.
Tower and Antenna Project Home
Previous Page Next Page