Economically Raising My Antenna

[Stone]

Good day! I have a question for an antenna installer. I have a 25 foot free standing tower. I think it is a Rohn Type. The picture shows the climber setting the new TV antenna and my radio antenna. Not the best picture but at least you get a closeup of the tower. The other photo shows the entire tower before my monster antenna was removed. What I want to do is get my radio antenna up another 20 feet. Was thinking two standoffs about 5 feet apart one above the other, Then finding an aluminum mast with a thick wall, Maybe 1-4 inch, and mount the radio antenna to that and the mast to the standoffs. The antenna specs are also attached and is only 24 inches in height. Also on the light side. Hope I gave enough info.  Any comments?  Thank You! Have A Great Day!

[SteveShannon]

How is your TV antenna attached?  Do you have it on a mast which is mounted to the center of the top section of the antenna?  If so, simply consider replacing that mast with a longer one that extends through the TV antenna and up to the level you want your radio antenna. That could save you getting standoffs.

Edited to add: don’t forget that placing your antenna on a tall mast will drastically increase the torque on the tower as a result of wind loads. 

[WRXB215]

1 hour ago, Sshannon said:

That could save you getting standoffs.

Yeah! Don't be so "standoffish!" 

Sorry for the bad joke, I couldn't resist.  

[Stone]

My antenna for the tv and radio at the present time is attached to the center of the tower and the rotor is about 10 feet down from the peak. I do not use the rotor as such. I have "Tweaked" the tv antenna, but for the most part it is stationary. To extend the center mast another 20 feet, I would have to get a 30-35 foot mast to reach to the rotor. As far as wind loading goes, I am on a hill but in a slight valley near the top surrounded by trees. I make a couple repeaters, However my simplex operation is lacking. Another 20 feet would allow me more than 3 miles base to mobile and strengthen my signal to the repeaters 17 and 35 miles away respectively. I will check into simply getting a longer mast pole. Any suggestions on something heavy duty enough to just extend through the middle? Thank you for your advise!

[SteveShannon]

Look at masts at DXEngineering.com. 
If you were only going 10 feet I would look at top rail for chain link fence. It’s available up to 20 feet long. 
However, if you have a rotator you really need to stay under the weight limit of your thrust bearing. I don’t have any idea what that is. You might be back to your stand-off idea. You too could end up with a tower like this: 

[Stone]

Thanks! Will check out DX Engineering. Going so tall of a mast is why I was considering stand off mounts. One above the other spaced about 5 feet apart with a 25 foot mast with a thick enough wall so it would hold up freestanding off the tower. using 5 feet of mast for mounting, that would get me the twenty feet I am looking for. With lmr400 going to the radio antenna mounted the way it is now, I am not a big fan of moving the TV antenna with the two on the same mast. So figure kill two birds one stone. Get the height I need for comms and get some freedom back if I need to move the TV antenna around. I thank you for your advise. It has been taken to heart! God Bless and have a wonderful day!