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