Tower Talk Reflector: [TowerTalk] Upside down mast
Frank Donovan W3LPL
Sun, 21 Dec 97 04:57:23 -0800
I used just this approach 25 years ago with a 3 element 20 meter
monobander ten feet below the top of the tower. Unless you are using a
very small antenna, you will need two short horizontal masts -- one above
the other -- otherwise the
"upside down" mast will surely slip on the single short horizontal mast.
I was using a prop-pitch, so rotator performance was not a big issue...
> NW9G > Ten Tec > CW (email@example.com)
> Sat, 20 Dec 1997 21:18:48 -0500
> There was a thread a few months back about this subject. I fully
> understood just what this guy was proposing. I thought the idea
> was fantastic, as long as it was not structurally damaging to
> the tower. For those that don't know what this is:
> Short mast out the top of a tower with an antenna on it.
> Another piece of mast apx 18" long attached to this short mast
> going horizontal with another vertical attached to it going
> back down the side of the tower with an antenna attached to it.
> This means you would have an antenna sticking out the top on a mast,
> with another antenna that virtually rotates around the tower a few
> feet below and is attached to this same mast using one rotor.
> Question: has anyone actually done this?
> Can it be done with light weight mast using small tribanders on
> short pieces of this mast?
> How hard is it on the rotor?
> I'm not an engineer but the idea of this sounds temping for me to put
> up that new force 12 warc 7 antenna they just got below my
> tribander without "redoing" my entire tower top.
> Just didn't want a structural nightmare to follow.
> Thanks guys and Happy holidays....Steve
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