We have essentially this setup, tribander on top at 82' ( 34XA, 68 lb, 9
ft2 ) - 2el 40 at 70' ( CC402CD 44 lb, 6 ft2 ),
on a guyed tower. Been up over 20 years and works fine.
The reasoning was, one of the antennas was definitely going on a sidemount
so we wouldn't have a long mast and maintainability hassles servicing
antennas and rotators if needed, Separate rotation of antennas is also nice
The 40 was the lightest and least wind load, so it went on the sidemount.
Ability to rotate individual antennas allows one to see whether or not
there is interaction between antennas (turned out to be insignificant in
our installation)
Everything is easily accessible and removable/replaceable.for servicing, if
needed, no lifting/dropping of the mast or sliding up/down of antennas
required - conveniences increasingly appreciated as geriatrics set in. The
antennas foto on QRZ has high resolution and can be inspected closely by
zooming the browser (CTRL-Z with Chrome).
Between the two beams, a fixed one-element 30m dipole @ 76' was added 10
yrs ago.
73, Don N7EF
On Fri, Oct 17, 2014 at 4:23 PM, Tony Brock-Fisher via TowerTalk <
towertalk@contesting.com> wrote:
> At moderate heights (70-80') and assuming mechanical concerns are not a
> factor, I vote for the tribander on top. If you do HFTA for the antennas at
> around 80 feet, you will find that for usual arrival angles, raising the
> tribander by ~10 ft improves gain by around 1 db, but lowering the 40 by
> ~10 feet only degrades it by less than one db. I'll take 1 db on three
> bands over less than 1 db on one band any day.
>
> And I did! I have had the tribander at 80 feet and the 2 element 40 at 71
> feet for 20 years; wouldn't change back.
>
> Tony, K1KP
>
>
> Sent from my iPad
> _______________________________________________
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