[TowerTalk] 40/30 antennas on same mast

[Jim Thomson]

Date: Sun, 15 Jul 2018 21:06:11 -0400
From: N1BUG <paul at n1bug.com>
To: towertalk reflector <towertalk at contesting.com>
Subject: [TowerTalk] 40/30 antennas on same mast

<I have a full size 40 meter rotatable dipole which I plan to install
<at 105 feet.

I want to put 30 meters on the same mast if possible. I had
considered two options but am not sure if there will be problems
with either or both.

Option 1 would be to add a 30 meter element to the existing 40 meter
rotatable dipole, making two parallel elements with one a few inches
above or below the other, common feed. I am not certain how well
this works on bands that are not widely separated in frequency.

Option 2 would be to put a full size 30 meter rotatable dipole
higher on the mast. The maximum achievable vertical separation would
be 10 feet with 40 meters at 105 feet and 30 meters at 115 feet. I
am not convinced this won't become a two element beam pointing
straight up!


Thanks,
Paul N1BUG

##  well, you could space em ur proposed 10 feet..and place them at right angles.
Then not only would there be zero interaction, the  wind load on the mast and tower
would be greatly reduced.   Only one of them can be broadside to the wind at
any time.    The mast however, is always broadside to the wind. 

Jim  VE7RF