Steve wrote:
><< > 4. Is anyone using utility-pole type long (4') fiberglass insulating
>rods at
> > the top of their towers? ...
>
> AM broadcast stations use them all the time but they're just part of
the
>guying hardware - a big insulator. I think the smallest size they come in is
>around 15,000 pounds breaking strength. Should be plenty for typical ham
use.
>
> A 'torque arm' would have to be rigidly connected to the tower to do
any
>good. These insulators just have shackles on the end. Like my grampappy used
>to say, "couldn't hurt".
Towertalkians may be interested to know that Joslyn makes 21-foot
fibreglass insulators with a breaking strength of 7,500 lb or so that cost
me (when I built my tower 3 years ago) about $50 each at retail. They do a
great job, in my upper guys, keeping metal away from the yagi. But as Kurt
says, they are very flexible transversely, so there's no contribution to
torsional stiffness.
73, Pete Smith N4ZR
In wild, wonderful, fairly rare WEST Virginia
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