[TowerTalk] 20RE: 40/30 antennas on same mast

Dave AA6YQ aa6yq at ambersoft.com
Mon Jul 16 15:23:13 EDT 2018


+ AA6YQ comments below

<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!

+ Another alternative is use a tuner to make your 40m antenna usable on 30m.

+ I have a Force 12 420/240 at 80'; it's a 4-element 20m antenna and a 2 element 40m antenna sharing a boom. I use an Ameritron
ATR-30 to tune the 40m antenna on 30m. While I haven't made measurements, it feels about as directional on 30m as it does on 40m.
It's gotten me to 322 current entities confirmed on 30m (vs. 333 on 40m).

         73,

               Dave, AA6YQ



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