[TowerTalk] Stacking Antennas for different Bands

[Bill Parry]

Alex,

I have a C3E and a XM240. You are not going to have success using a stacking
distance of under 15 feet. I believe that mine are about 12 feet apart. I
put my antennas up in 2002 and noticed immediately SWR and front to back
issues on both antennas. My tower is 120 feet of Rohn 25 and a 21 foot piece
of steel tubing serving as a mast. The mast extends about 5 feet down into
the tower where my TailTwister is located.  I have two thrust bearings (be
sure to replace the bolts with stainless or you are going to have problems)
one at the top of the tower and one about 12 inches above the rotator.

I asked around and found the only solution for me was to rotate boom of the
bottom antenna (the C3E in my case) 90 degrees. I did this and both antennas
began to play properly. If I were you, I would assume that I was going to
have to do this and plan accordingly. I have no idea how the 6 meter beam
will affect the other two antennas, but I have been considering it as well.

Good luck, if you want a picture of my installation I will be glad to send
it to you directly.

Bill W5VX

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of PY1KS - Alex
Sent: Saturday, April 26, 2008 12:14 PM
To: towertalk at contesting.com
Subject: [TowerTalk] Stacking Antennas for different Bands

Hi Guys,

Maybe this subject was discussed already, but i did a search and couldn't
find any information about it.

Well, I'm back to HAM and I will building a new station and this time will
be real one!. hihihi...

So, I need some suggestions about how to stack my antennas. I will try put
the max information I can.

I will assembly a Tower around 40' and include a Mast around 20' but just
13' will stay to out of tower and 7' to inside and I will put a HAM IV as
well.

The antennas are. XM240 (Cushcraft), C3 (Force12) and a 6 el. for 6m.

Let's to the questions:

1)Will I have a performance problem assembling all of this 3 antennas on the
same Mast?

2) Which distance could be the best to separate each antenna of others?

3) The Ham IV should deal with this amount of weight easily?


So, I was thinking in the xmas tree example to build the antenna
configuration.

Any replies will be very appreciated!!!


Thanks in advance.

-- 
73's

PY1KS - Alex
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