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Re: [TenTec] New and Improved Terminology (NVIS origins)

To: tentec@contesting.com
Subject: Re: [TenTec] New and Improved Terminology (NVIS origins)
From: "Dr. Gerald N. Johnson" <geraldj@weather.net>
Reply-to: geraldj@weather.net, Discussion of Ten-Tec Equipment <tentec@contesting.com>
Date: Fri, 07 Jan 2011 21:33:15 -0600
List-post: <tentec@contesting.com">mailto:tentec@contesting.com>
You can solve your willowy tubing with stay wire braces, probably want 
to use a poly rope instead of wire. Stay wire braces have been used on 
slim masts, elevator legs (for grain transfer at an angle), crane booms, 
and vintage aircraft wings. Basically you start with a wire attached to 
the tubing at the top, go a few feet down and run the wire/rope over the 
ends of cross spacers that hold the wire out from the tubing then come 
back to the tubing for a single stay wire. It takes three or four for 
something vertical, the cross spacers are easier done for four wires 
than for three. The longer the spacer bar, the stiffer the construction. 
The more the spacer bars the stiffer the construction. There can be a 
cable or wire that starts at the top and passes over the ends of several 
spacers before returning to the tube at the bottom, but the middle 
spacers aren't as effective when the stay wire doesn't form an angle 
over the end. You can use multiple spacers and multiple stay wire segments.

An example is at:
http://dollingerfarms.aminus3.com/image/2009-08-25.html on the diagonal 
tubes of a farm grain leg.

I don't mean guy wires.

73, Jerry, K0CQ

On 1/7/2011 6:43 PM, Richards wrote:
> WHOA... RICK...  You understand my position exactly.
> ---------------------------------------------------------------------------------------
>> I understand your concerns and it sounds like the aluminum is
>> under-dimensioned.
>               Exactly.   Darn it...    At least the 6 and 10 meter
>               versions turned out well.   It is just that the 20 meter
>               version is, as you say, under-dimensioned.
>> I also understand the wish to use what you have, but that might actually be
>> a bad idea, depending on what you want to build.
>               I am sure you are correct...  I just hate giving up
>               on it as I have the tubing now.   But it is just too
>               wobbly and flexible in the wind.    I just need to
>               realize it and move on.
>> For me, the only logical choice of material is a telescoping fiberglass pole
>> and copper wire for the radiator.
>               I agree.   OR  I need beefier tubing and a stronger
>               element-to-mast plate.
>> They are light weight and because they taper, they are not so conspicuous
>> when viewed from a bit farther away.
>               I now employ two such fiberglass poles to support
>               a medium aperture receive-only Wellbrook loop antenna.
>               They have held up well in the winter snow, ice and wind.
>    >  Funny, I thought I was being specific with my rating of the 3 antennas.
>> "It's horses for courses."        Depends on what you want to do.
>> The first choice is, should it be monoband or multiband?
>               Yes.   Monoband.
>               I already have a 43 foot aluminum multiband monopole
>               with 65 radials.   Works rather well, actually, considering
>               all the inherent compromises.
>> If multiband, I personally would only run with a VD.  I hate traps (break,
>> lossy, collect water) and I am to lazy to put a lot of radials down.
>               Agreed on all objections.
>> If monoband, anything will work, as long as it is built well, following the
>> multitude of excellent tips we have read on this thread.
>               Yes...   It boils down to this -- I must either beef up
>               the aluminum so it is "stiffer" and does not wobble or
>               vibrate so much in the wind....or ... opt for a
>               lighter-weight support material (such as fiberglass)
>               that holds up well to ice, wind and summer heat.
>               The fiberglass may be the right tool for the job.
>               It would certainly be lighter and would probably
>               stand up to the wind without wobbling as much
>               as the aluminum tubing.
>               Thus... while I develop a fiberglass version of my
>               20 meter vertical dipole or ground plane... I should
>               stick up the 6 and 10 alum. dipoles I now have (which
>               are plenty study and tune to 1:1 with ease...)  and
>               maybe string up the 40-6 OCF dipole I have built,
>               and continue developing the 20 meter antenna design.
>> On the one hand, I hate to have to tune a matchbox, and my shortened VD will
>> always require a matchbox.
>               My goal with the 20 meter VD or ground plane is to
>               finally have a really robust, study 20 meter antenna
>               that does not require a tuner/transmatch.  I believe
>               it will be way more efficient than my big stick vertical
>               monopole.
>> I purchased a 1000 Watt Palstar automatic tuner, but haven't tried it yet.
>> Maybe that's the solution I've been looking for.
>               I have one of those now!   Palstar AT-AUTO, as well as
>               the Palstar AT2K --- they work swell.   The AT-AUTO
>               is a breeze to use.   I think you will like it.
>> There's so many antennas I d like to try.... and the wife never lets me put
>> up more than 3 (preferably 2) except for a few days for a contest weekend,
>> when I put up 5 or 6 more!  :-)
>               Perhaps, you could try a different wife...    ;-)
> THANKS for the specific reply  - right on track.
> ================   James -K8JHR  ====================
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