[TowerTalk] telescoping steel mast vertical

[Chris Adams]

Frank T. Brady wrote:
> 
> Hi all -
> 
>  I've just purchased two Rohn H50 steel telescoping antenna support masts.
> They have 5 sections that extend to about 50 feet.  I bought them to support
> a G5RV or Double Zepp, but as I was surveying the installation area I
> thought maybe they could serve a dual purpose as verticals for 20 and/or 40
> meters.
> 
-------------  snip

Frank,


I have considered doing what you are suggesting (i.e. verticals with
telescoping mast although even suspending horizontal antennas wouldn't
be a bad idea either) but have never gotten around to it.

That said, there's an article in the May 1994 issue of QST by Bob
Haviland, W4MB on the ability to use a telescoping mast to support ham
type beam antennas.  That said, he makes a passing mention of using the
mast as a vertical....

"The TV mast itself can be used as a vertical antenna with no
additions.  Add a set of three to six wires parallel to the mast, and up
to a foot or so from it, to form a cage for low loss and improved
bandwidth.  A bottom insulator of fiberglass cloth and resin can be
used, or the wires can be fed as a folded dipole.  A 3, 5 or even 10
foot capacity-hat is within the design capability of these masts (he
means they will stay standing).  The usual rules about good grounds
apply."

Another good reference is the artical  "Vertical Antennas: New design
and construction Data" by Doty-K8FCU, Frey-W3ESU (K4VX now??) and Mills,
K4HU.  This artical can be found in the ARRL Antenna Compendium, Volume
2.  It mentions the folded monopole which is what I "think" Havliland is
actually referring to.


chris, n4vi

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