OK, here's a plan for the existing guy points (30 / 60 / 90)
on your 100 ft tower. Use Philystran or insulated guys.
100+ ft C3E (C3 + 10M reflector = 2L20 / 2L15 / 3L10)
90 ft 2L40 + 80M rotary dipole? (+30M dipole or 2L30)
60 ft C3E
35 ft C3E
Other tribanders can be substituted for the C3E's if you
like or already have something else. Stacking and
rotating 7 to 10 monobanders would be more expensive,
result in higher loading of the tower and suffer from
destructive interactions from close spacing. IMHO,
the tribander stacks are a better one tower solution.
A small rotor will handle the top C3E. A ring rotor or
sidemounted rotor / swinging gate will provide rotation
for the 2L40 + other antennas.
Ring rotors or swinging gates with HAM series rotors
can handle the lower C3E's.
>From memory of some stacking arrangements I looked at
years ago, stacked 2L40's looked very good at 160/80 ft.
which scales to 40 ft separation on 20, 27 ft on 15, 20 ft on 10.
I was planning on a 3L20 stack at 65 and 130 ft but found that
50 / 100 ft looked much better. This scales to 33 ft spacing on
15 and 25 ft on 10.
Notice that 25 ft separation is near optimum for a 2L 15 and 3L10
which corresponds to the lower C3E stack above and 40 ft separation
is near optimum for a 2L20 stack which corresponds to the top C3E
Of course you can use each stack (upper pair and lower pair) on all
3 bands with some slight compromise. It is a powerful combination
at moderate cost and loading. Use a switching arrangement which
allows for feeding each antenna separately or in pairs. You might
want to model all 3 to see how they interact with the unequal
spacing. Matching 3 antennas is more complex than the simple pairs.
Hopefully your tower can handle that amount of loading. The 18 ft
booms on the C3's help minimize torque on the tower.
73 / GL, Tom N4KG
On Tue, 14 Dec 1999 07:58:15 -0800 "Dinkelman, Michael W."
> Hello Tom
> Thats difficult. It's a military surplus aluminum tower
> (bolted together). About the size of Rohn 55 for the
> first 50 feet and then one taper to Rohn 45 size for the
> top 50'. Guys at 30,60,and 90. Pretty strong actually.
> I would say comparable to Rohn 45. Had Steve/K7LXC come out
> and look at it last summer before it went up. Didn't
> see any problems with it.
> > -----Original Message-----
> > From: firstname.lastname@example.org [SMTP:email@example.com]
> > Sent: Tuesday, December 14, 1999 5:58 AM
> > To: firstname.lastname@example.org
> > Subject: Re: [TowerTalk] The ultimate one tower system?
> > You neglected to mention how strong your tower is (R25, 45, 55?)
> > and where the guys are located. Please advise.
> > de Tom N4KG
> > Why pay more to get Web access?
> > Try Juno for FREE -- then it's just $9.95/month if you act NOW!
> > Get your free software today: http://dl.www.juno.com/dynoget/tagj.
Why pay more to get Web access?
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