Topband: Telescoping Fiberglass Mast

[Michael Tope]

----- Original Message ----- 
From: <W2pm at aol.com>

> The big issue I have found with these telescoping masts is that they 
> cannot
> hold much weight up at the top ends and even # 14 wire will pull down the 
> top
> significantly if you are trying to use it in an Inverted L pattern and 
> will
> stress the pole eventually fracturing it.  These are fine for temporary
> installations but I doubt they'd last much longer than year, or less, 
> unless
> efforts are made for strain relief.
>
> You could use a section or two down - Ive found decent strength to avoid a
> pulling down effect can be had about 7 - 9 ft down from the top. But 
> again,
> this  is fibre we're dealing with and not rigid aluminum so you have to 
> think
> about  practical life span. In very cold weather you'll find these things 
> can and
> do fracture very quickly and are not repairable. But for a straight-up
> vertical  support - a base loaded 60 ft monopole (maybe someone could 
> manage to
> avoid the  top section drooping with a clever arrange of  T configuration 
> top
> loading  wires acting as guys) these are fine even for longer term  use.

I bought one of these recently to hold up the far end of my top
loading wire for my 160 meter inverted-L:

http://www.wonderpole.com/custom_telescoping_poles.html

It is a bit flimsy when fully extended to 40', but not so bad
that it wouldn't hold if my top loading wire without guying. If
you partially extend each telescoping section the mast is
pretty stiff. The great thing is that each section has a knurled
twist-lock so the sections won't collapse if there is significant
vertical load. I keep my extended about 20' in case the Santa
Ana winds kick up while I am at work. If I want to do some
serious topbanding, I can have it fully extended to 40' in a few
minutes (mine is setup on my 2nd story front-porch so the
overall height is ~50' when fully extended).

I just got mine, so I can't report on longevity in the California
sun and smog yet. BTW, be prepared to spend some money.
These things aren't cheap.

73, Mike W4EF......................