[TenTec] New and Improved Terminology (NVIS origins)

[Richards]

Thanks, Jerry.   A lot of buckshot in that one shell !   I had discussed
with my local friend the notion of putting a wooden dowel through
the tubing, and you give a fine exegesis for why that is a better plan.

Another idea that struck me this evening, is to double up the tubing
for the originally planned dipole, and make it into a single element
vertical made from double tubing - and then add wire radials that can
also play as light weight guy wire-rope supports.

		HOWEVER... I tried there this afternoon, and it makes
		the element way too heavy and it still sags a bit, so
		doubling the tubing is not the solution, either.

		The wife and I looked at fiberglass crappie poles today,
		and we are thinking the Spiderbeam poles are now
		the leading contender.

Yes... the expanding  foam might work to _slightly_  dampen vibration 
(the way Hy-Gain  runs a rope inside some of its yagi beam elements to 
dampen vibration.)  But you and Rick both explain how it won't do enough 
for the rigidity and support I am looking for.

Oh well...   one more idea on the scrap heap !    I am, however, having 
great  fun working this out.

Thanks for the gloss on tubular engineering.    As they used to say in 
the 1980s....  "Totally tubular, man..."    ;-)

===============   James -K8JHR  ========================

On 1/8/2011 7:29 PM, Dr. Gerald N. Johnson wrote:

> were it bends (and sometimes breaks). Column load is more complex but
> bending is a part of failure if it doesn't buckle. Wood inserts help
> slow buckling too. I'm not so much a fan of foam, I don't think its
> strong enough in the tube to keep the tube round and full diameter,
> though foam faced with very thin metal shows a lot of strength, I think
> that structural foam is a lot more dense than foam in place out of a can.
>

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