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-   -   SteppIR support question (https://www.radiobanter.com/antenna/138955-steppir-support-question.html)

Bill Ogden[_2_] November 29th 08 02:44 PM

SteppIR support question
 
I have the 30/40 add-on for a 3-element SteppIR. Seems to work well.
However, the middle element (a double element with a "U" fitting at each
end) droops more that the two simple elements. This probably does not
affect the operation of the antenna, but it looks odd.

I have been thinking about extending the mast a few feet (probably with PVC)
and using dacron rope from the mast to the ends of the middle element, to
give a little more vertical support. However, unless the mast extension is
rather long, there would be a substantial horizontal force pulling the ends
of the element toward the center.

Has anyone done something about the drooping center element?

Bill - W2WO



Sal M. Onella November 30th 08 04:03 AM

SteppIR support question
 

"Bill Ogden" wrote in message
...
I have the 30/40 add-on for a 3-element SteppIR. Seems to work well.
However, the middle element (a double element with a "U" fitting at each
end) droops more that the two simple elements. This probably does not
affect the operation of the antenna, but it looks odd.

I have been thinking about extending the mast a few feet (probably with

PVC)
and using dacron rope from the mast to the ends of the middle element, to
give a little more vertical support. However, unless the mast extension

is
rather long, there would be a substantial horizontal force pulling the

ends
of the element toward the center.

Has anyone done something about the drooping center element?

Bill - W2WO


If you used an intermediary structure, you could eliminate/reduce
deformation of the element.

I can't engineer it for you but consider that you could have your Dacron
rope attached to another structure, perhaps more PVC, suspended above the
drooping element by rope loops on both sides, each supporting one side of
the (now no longer) drooping element. ( A suspension bridge comes to mind,
in that the weight of the roadbed rests on the vertical suspension cables,
whose stresses are transferred in turn to the towers and the anchors.)

Just a thought



ml November 30th 08 11:42 AM

SteppIR support question
 
In article ,
"Sal M. Onella" wrote:

"Bill Ogden" wrote in message
...
I have the 30/40 add-on for a 3-element SteppIR. Seems to work well.
However, the middle element (a double element with a "U" fitting at each
end) droops more that the two simple elements. This probably does not
affect the operation of the antenna, but it looks odd.

I have been thinking about extending the mast a few feet (probably with

PVC)
and using dacron rope from the mast to the ends of the middle element, to
give a little more vertical support. However, unless the mast extension

is
rather long, there would be a substantial horizontal force pulling the

ends
of the element toward the center.

Has anyone done something about the drooping center element?

Bill - W2WO


If you used an intermediary structure, you could eliminate/reduce
deformation of the element.

I can't engineer it for you but consider that you could have your Dacron
rope attached to another structure, perhaps more PVC, suspended above the
drooping element by rope loops on both sides, each supporting one side of
the (now no longer) drooping element. ( A suspension bridge comes to mind,
in that the weight of the roadbed rests on the vertical suspension cables,
whose stresses are transferred in turn to the towers and the anchors.)

Just a thought


if the parts are made by the original manuf, perhaps you should
contact them to see what they recomend to releive that droop,
and might even have a pre made solution, it's worth a email
to them at least


if they don't offer premade hardware perhaps they would at leas
suggest a solution that wouldn't unduly effect the antenna

Art Unwin November 30th 08 04:22 PM

SteppIR support question
 
On Nov 30, 5:42*am, ml wrote:
In article ,
*"Sal M. Onella" wrote:



"Bill Ogden" wrote in message
...
I have the 30/40 add-on for a 3-element SteppIR. *Seems to work well.
However, the middle element (a double element with a "U" fitting at each
end) droops more that the two simple elements. *This probably does not
affect the operation of the antenna, but it looks odd.


I have been thinking about extending the mast a few feet (probably with

PVC)
and using dacron rope from the mast to the ends of the middle element, to
give a little more vertical support. *However, unless the mast extension

is
rather long, there would be a substantial horizontal force pulling the

ends
of the element toward the center.


Has anyone done something about the drooping center element?


Bill - W2WO


If you used an intermediary structure, you could eliminate/reduce
deformation of the element.


I can't engineer it for you *but consider that you could have your Dacron
rope attached to another structure, perhaps more PVC, suspended above the
drooping element by rope loops on both sides, each supporting one side of
the (now no longer) drooping element. *( A suspension bridge comes to mind,
in that the weight of the roadbed rests on the vertical suspension cables,
whose stresses are transferred in turn to the towers and the anchors.)


Just a thought


if *the parts *are made by the original *manuf, *perhaps you should
contact them to see what they *recomend * *to releive * that * droop, *
and might *even *have * a *pre made solution, * *it's *worth *a *email
to them at least

if they don't offer * premade hardware * perhaps they would at leas *
suggest *a solution *that *wouldn't *unduly *effect the antenna


I had a simiar case with a fibre glass tube of extremme length.
I injected insulated foam inside the tube and deflection was greatly
reduced.
This ofcourse is no substitute for securing a stiffener of a suitable
material to
the center length of the radiator
Art


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