The top plate I use just has an approx 2.125 hole, no bearing, no etc. The
mast extends about 3 inches above the top plate.The lateral movement is nil and
any metal to metal wear from rotation or lateral movement is negligible. I
took this system down in summer 2011 to repaint. The wear after these years
was negligible, ok, it did remove the paint. Remember our systems rotate at
about 1 rpm. My approx 16ft vertical mast is 2" od with about 0.18 wall.
BTW, this system has gone through many 60-70mph winds in our summer monsoon
winds of NM (also windy season is spring and fall). I do not worry which
direction the antennas are pointing/parked. The 2 side arms are about 6ft
apart. Rotor, T2X, supports all weight.
This is a proven "KISS" system, 20+ years.
Oh, forgot to mention the tools needed to build this: tape measure, hack saw
and my drill press.
The antenna system, not a close up, is shown on QRZ dot com. One can get a
really rough idea. I do not have a web site to post any detail info/pictures.
Have not checked steel prices but maybe $25 material cost depending upon one's
scrounging abilities. I am building another side mount this spring, more yagis
to mount (can never have enough).
Arne N7KA
----- Original Message -----
Yup! That works too. How did you handle the "bearing" above the rotor? Just
a short piece of pipe larger than the mast? Most folks don't have a lower
mast support for their Ham-4 or Tailtwister though.. :)
73
Jim W7RY
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