[Towertalk] More on tree antenna mounts

W0UN--John Brosnahan shr@ricc.net
Sat, 07 Sep 2002 10:29:32 -0500


>
> > > Another way is to string a guy wire between two trees; use it to hang a
> >  > rotor upside down and a beam hangs from the rotor.
> >
>     A good way to fill up a HAM IV or T2X with water. Don't know about

Don't think you actually have to hang the ROTATOR itself upside
down. Just mount the normal top side to the fixed guy by using a
short vetircal pipe mast welded to the center of a long horizontal pipe
which is supported by the horizontal cable.  Then mount the beam to the
normal bottom side of the rotator.  Easy to do if the bottom side has
a mast mount clamp, but it could also be done with a flat plate bolted
to a flat-bottomed rotator and then the plate could be drilled for U-bolts
to attach the boom.

Probably not all that wonderful around here were the trees are only
25 ft tall, but it is an interesting idea conceptually--at least
for relatively modest beams.

I could also see this technique used between two towers when tuning
a beam and rotation is also desired.  But not sure how long the
swinging would continue after movement (making the cross-pipe long
would greatly reduce the rotation instability, but not the bouncing
and swaying mode.

Probably most useful as a Saturday-morning mental exercise than
as a real project--but it is always nice to have "secret weapons"
for unusual circumstances--such as Field Day in the Pacific NW.

John   W0UN