Antennas

[GREGT]

I currently have (2) free standing towers. One tower is 48 feet and the other is 32 feet. I want to set up a ground plane antenna and a set of beams as well. I would like to know if I would suffer any major losses by putting my ground plane antenna above the beams and using only one tower? I'm also not sure how far the beams should be above the ground so some input on that would also be welcome.

Thank you,
Greg T.

[MDYoungblood]

I have seen a few antenna setups where they installed a 3 or 4 element beam horizontal and had vertical antenna on the mast above it. Actually it should work quite well, the beam should not "see" (interact) with the vertical and the vertical would benefit from the beam as a ground plane. The vertical can't be a ground plane type ie: Maco 5/8 or HyGain SPT500, unless you leave the ground radials off because they would interfere with the beam.

3's

Greg

[jessejamesdallas]

You said these are "Free standing " towers....what is the wind/antenna load rating on them?

If you overload the tower with two antennas, it's not going to be in the air very long...

I have a Free Standing 40' tower and the antenna load is only 4.5 sq. ft. , my MaCo Shooting Star beam has a surface area sq. ft of 6, which overloads what the tower is rated for (plus there's also the rotor to figure in)

Way I got around the numbers so I didn't have to worry about it being overloaded, is I had to add guy wires...no way around it, but it worked...been up now for over 6 years and quiet a few thunderstorms and hurricane force wind gusts, and it hasn't budged any...

If the towers are aluminum, you can't just attach guy wires just anywhere either, or you risk breaking a weld...Best place to anchor the wires is at the rotor plate, since those are usually made out of steel and would be attached to all three legs of the tower.

[GREGT]

I will have to look them up on Rohn's website after I measure the bases, these are all steel with "X" bracing. They are both large, the 32' is just the base of a 64' tower as the previous owner just wanted/kept the top section. Neither one is up now, I do know they require a very large and deep reinforced concrete base. The smallest base on Rohn's website takes about 5 yards of concrete with a hole over 4 foot deep, these towers will require more that that. Thank you for your input and advice. I'm the kind of guy that will spend more time doing research and planning than the actual work will take. Sounds like putting them both up is the way to go. I just don't want to do them both at the same time adding more to the cost as I'll have to rent a backhoe twice.

[GREGT]

Does anyone have a recommendation on the height a Beam Antenna should be from the ground? Years ago, like 40, someone told me you do not want the beam antenna to be to high off the ground, but I'm not sure that is correct?

[jessejamesdallas]

Does anyone have a recommendation on the height a Beam Antenna should be from the ground? Years ago, like 40, someone told me you do not want the beam antenna to be to high off the ground, but I'm not sure that is correct?

Mines at 40' and I can talk all over the Country!

If I could get it up another 20' tho I would...

Need to have it higher than anything else near by that may block your signal...

[GREGT]

I guess I could put the beams on the 48ft tower and the ground plane on the 32 with a 10 foot mast above the tower and that should work well. Thank you!

[jessejamesdallas]

I guess I could put the beams on the 48ft tower and the ground plane on the 32 with a 10 foot mast above the tower and that should work well. Thank you!

Or stick the 10' mast on the 48 footer and have both antennas on one tower...I would still consider adding guy wires tho...

[Turk182]

I use my 12/17 meter Cushcraft A3WS for 11 meters (with a tuner) on top of my 10/15/20/40 meter Cushcraft A3S on a 47 ft. Rohn 25. The top beam is about 55 ft. up. and have talked all over the world on Ham and all over N. America on am. It's real important to run good coax like LM-400 and a good grounding grid. (See icon picture.) When conditions are right, watts won't matter much. I got N. Michigan on am barefoot, and Manitoba Canada on LSB. When conditions aren't, I run my KL-505V near full throttle and usually get it done.