Dave:
1. Maybe Dillsburg Aeroplane Works near Harrisburg, PA might be a source
for aluminum. http://www.dimebank.com/monster/burst/00229.html .
2. Torque-balancing is an attempt to distribute the effective area of
all the elements, including the boom, on a Yagi antenna system so that net
torque on the mast is zero, irrespective of the direction of the wind. This
will have the indirect effect of minimizing the torque required from the
rotator to turn the array.
My Bencher Skyhawk Yagi has a couple of PVC components among the director
elements that, supposedly, help to balance or reduce the net torque on the mast
by compensating for the necessarily longer reflector elements. You can see a
photo of one of the two <torque compensators> at:
http://www.bencher.com/sky_hawk1.html . The short (PVC) tube on the left
between the 10M and 20M directors compensates for the greater amount of element
material on the reflector side of the mast. Not clearly seen is a vertical
flag of PVC plate that mounts above this PVC tube. That flag compensates for
the greater boom length on reflector side of the mast. Yes, both of these PVC
items add a bit to the total wind area of the Skyhawk.
I'm guessing that having a better-balanced Yagi array permits the rotator
to turn it with less effort in a wind than if the Yagi were left uncompensated
or unbalanced. I don't believe that the inertia of the array is affected by
such compensation.
73 de
Gene Smar AD3F
-------------- Original message ----------------------
From: "David J Windisch" <davidjw@cinci.rr.com>
> Hi, all concerned:
>
> 1. Searching for 24' of 2"OD X 0.25" wall X 24' length 7075 T6 alloy
> aluminum mast has turned up nothing. Any help on sources out there, pls?
>
> 2. Is "torque-balancing" of a boom a balance of sorts between wind effects
> and inertial start/stop forces on a rotator?
>
> TIA & 73,
>
> Dave, N3HE
>
>
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