[SECC] Tower Mast

[Bill Coleman]

On 2/14/02 12:45 PM, Macie, Gordon at gmacie@xmmcorp.com wrote:

>Thats what Rick NQ4I suggested.. I am following his advice... I have a 4 el
>20 a 5 el 15, 2 el 40, 6 el 6 mtr. 

Let's see 17 feet of mast, 3 feet in the tower, that's 14 feet of mast 
above the tower for four monoband antennas.

Aren't they gonna be a little close for comfort? 14 foot separation 
between the 4l20 and the 2l40 seems ok, but where do you put the 5l15?

>I have been reconsidering my plans. I
>have been looking at a c31xr or a tennadyne log periodic.. if i go with
>either i would eventually want 2 stacked high / low for different angles...

Stacking is a great idea, but there are a lot of variables. How high is 
your tower? I wouldn't stack a tribander toward europe lower than about 
45 feet -- although one on the carribean could be placed perhaps down to 
35 feet. Monobanders are a whole 'nouther matter, since they can be 
stacked at variously hieghts / distances. In general, you need more tower 
space to stack a group of monobanders. But you can pick optimal stacking 
distances. Stacked tribanders are a compromise.

>I have gotten a little cautious toward pursuing my initial goal
>of 3 100 ft towers. I have been having some knee trouble and not sure ill be
>able to do any climbing and that may just be too much maintence. I am
>confused with all the options. Have gone back and forth considering a free
>standing trylon and just use a crane. Maybe 1 guyed and 1 freestanding.. I
>AM CONFUSED !!!!. 

Try thinking of it another way. What do you want to accomplish with your 
antenna set up? Do you need antennas to feed two different radios, or 
just one? For the first radio, what would be sufficient for each band? Do 
you want to cover multiple propagation angles? Which angles are 
important? Do you want to cover multiple directions? Can you rotate those 
directions, switch them, or do you need to cover them similtaneously? 
What bands do you need to cover? Do you need gain on each band 
(especially for the low bands)?

What do you need for the second radio? An R7? A dipole? A tribander and 
wires? More monobanders? Can you divide your antenna system by band and 
use one set of antennas for both radios? (Works great with monobanders -- 
which is how W4AN does it)

Think about each question and draw up a Good, Better, Best scenario. Try 
to consider how much each improvement is worth to you. Try to narrow it 
down to the least antenna configuration that gives you the maximum value.

Now, figure out how many towers you have to put up to do that. You can 
put a lot of stuff on three towers. NQ4I has a full M/M station going on 
three towers. 

(Yes, that's a lot of drivel from a guy who just has a tribander at 50 
feet)

My wife has been looking at some nearby property with 10 acres (that's 
far more than we can afford right now). I've run the mental exercise -- 
if I moved, what might I put up?

I came up with the following hypothetical solution:

Tower 1:
Force-12 tribander with 2 el 40m @ 95-100 feet, rotatable
Force-12 tribander @ 70 feet, fixed on europe
Small tribander @ 45 feet, fixed on carribean
80m four-square suspended from ropes or sloping dipoles to EU, West, 
Carribean
160m shunt feed

Tower 2:
Medium to large tribander with 40m @ 65-70 feet, rotatable
80m inverted V or dipole

This particular solution uses a lot of tribanders, which avoids a lot of 
antenna interaction headaches. The first two tribanders are stackable. 
The second tower is mainly for the second radio. 

The one key feature is that the tribanders can be pointed at JA, EU and 
the Carribean in a switchable fashion. I used a setup at NQ4I's 20m 
station and am sold on the switching configuration. 

The compromise is in the tribanders. Monobanders might require long 
rotatable masts, or swinging side mounts, or more towers to hold a bunch 
of fixed monobanders. I dunno, perhaps I need to run the thought problem 
through with monobanders in mind....

>I dont like crankups they scare me..

They can be scary. They are usually good for holding ONE antenna. 
Freestanding or guyed towers are more versitile.

>Who is the guy with the masts do you have a phone number ?? what part of
>town..

Bill Wall. K4OGG gave me the number of (706) 466-4353 four years ago.

I think he's in Lawrenceville.





Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901


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