TREE OR TOWER?

[BammBamm]

JUST WONDERING. I HAVE READ A LOT OF PEOPLE SAYING TO MOUNT BASE ANTENNAS AWAY FROM SURROUNDING OBJECTS. YET SOME PEOPLE TALK ABOUT MOUNTING THEIR ANTENNA IN A TREE. WILL THE TREE INTERFERE WITH PERFORMANCE OF ANTENNA? SHOULD TOP OF ANTENNA EXTEND BEYOND TOP OF TREE? I HAVE A OAK TREE ABOUT 20 FOOT FROM MY TOWER AND IT IS TALLER THAN MY ANTENNA AND UPON LOOKING AT THE TREE I KEEP THINKING ABOUT THE 20+ FOOT OF MORE HEIGHT I COULD GAIN BY MOUNTING IT UP THERE. PLUS BY PAINTING MY IMAX DARK BROWN IT WOULD BE PRETTY STEALTHY. IF THIS COULD WORK I COULD SELL MY 30 FOOT TOWER AND BUY OTHER TOYS.

 

[Shockwave]

If you run under 500 watts, sell the Imax and the tower. Buy a Gain-Master and some LMR-400 equivalent coax and put it in the tree. If you can get the antenna out of the top of the tree, it will help. I've used vent pipe antenna mounts with great successes in trees many times. If one of the top limbs is even close to vertical you can adjust these mounts to stand the mast straight.

If your mast is strong enough these mounts make using a long mast easy in the tree. Just get the mast with the antenna mounted on it attached to the vent pipe mounts in the tree with the mast hanging below the mounts. Then push the entire assembly up and lock the mounts in place. Buy more then one set of mounts so you can double them up if you do this.

 

[Captain Kilowatt]

For me a tree is not an option I personally would even consider.Besides the fact I use rotary beams that would make using a tree all but impossible, I prefer the stability of a free standing tower. Installing an antenna on a tower is much easier than in a tree and unless the height difference is considerable the difference is likely to be slight and hardly worth the effort or risk of damage unless the tree top is large and stable. A tree top will sway in the wind andcan create a tremendous strain on the antenna base and mount.

 

[Shockwave]

Except that he's mounting a 7 pound fiberglass stick. Not much stability required to hold that thing up compared to your directional antennas. Personally I wouldn't consider installing 30 feet of tower just to hold up a vertical stick when the tree is already standing 20 feet higher. Now if he said Shooting Star on the short tower or vertical stick in the tree, I'm going with the tower too.

 

[BammBamm]

I already owned the tower just moved it from my parents house to here about 2 months ago. I have some kind of problem with the imax though, when I put it up I had a swr on 1 and 40 of about 1.3 with no needle movement on 20. Today I checked it and I'm 1.7 at 1 and over 3 at 40? This antenna has never seen more than about 500 watts. I looked over the coax and continuity checked it with everything checking fine. I then connected the coax to a homemade dipole and had a swr of 1.5 on 1 and 40. I tried tuning the antenna but nothing seems to make a difference. I'm off tomorrow so down comes the imax to try to figure this out. And after reading the replies here I am thinking of adding a 20 foot mast to the top of the tower and adding guy wires. this would put the base of antenna about 45-48 foot in the air. Thanks for all the feedback and I'll let you know what I find on the inspection in the morning.

 

[Captain Kilowatt]

Except that he's mounting a 7 pound fiberglass stick. Not much stability required to hold that thing up compared to your directional antennas. Personally I wouldn't consider installing 30 feet of tower just to hold up a vertical stick when the tree is already standing 20 feet higher. Now if he said Shooting Star on the short tower or vertical stick in the tree, I'm going with the tower too.

It's not the weight as much as it is the leverage. Try holding that antenna in one hand at the base and then start moving it side to side and see what I mean. As the wind blows the antenna and treetop it is possible,depending on the tree and flexibility of the antenna, for the antenna to get out of sync with the treetop while whipping around and create a tremendous stress on the mount. I have seen a perfectly good antenna snap off at the base because of this in a windstorm while the neighbors similar antenna was fine. It was mounted on a solid tower at a similar height. If there is not much sway in the tree then maybe but I personally still wouldn't.

 

[Marconi]

I agree that trees and your home are not the place to mount an antenna. For one thing trees can be expensive items in terms of dollars, removal, and value to property. If you do it anyway, try not to trim the top. That stresses the tree and then bugs and disease can take hold.

Check your Imax for water in the bottom of the antenna. Make sure the weep hole in the bottom is not clogged up and that you don't have water in the coax. Take the sections apart and in the ends of bottom two hubs you can see where the radiator wires terminate and are soldered. Make sure that wind stress has not made one of these wires loose inside that little hole in the hub. You have to look close.

 

[Shockwave]

I do have to agree with you there Captain. Long term it certainly will put more wear and tear and the antenna due to the stress. I had a Sigma IV in an 80 foot oak for many years. When it finally failed in a storm it broke exactly where you said. Right at the base of the antenna.

I have seen the old fiberglass Big Stick antenna that has held up in town in a taller tree for over 20 years. They were built well for that use. If you pick the right antenna and tree, sometimes the height gained makes a tremendous difference in your coverage area.

Plus I can't see pouring cement with only 3 sections of tower to stand up an Imax? Seems a simple mast on the roof and perhaps a few guy wires would accomplish the same goal without the possibility of local zoning busting your chops over a tower footing.

 

[W5LZ]

Keep the tower, sell the tree.
- 'Doc

 

[BammBamm]

THANKS ALL

SHOCKWAVE YOUR ABOUT THE 5TH PERSON WHO HAS SAID THE SAME THING IN REGARDS TO THE TOWER. BUT LIKE I SAID I ALREADY OWNED IT AND DIDN'T WANT HOLES IN MY NEW ROOF. THE TOWER USED TO BE FOR A TV ANTENNA AND I WONDER IF I COULD FIND SECTIONS TO LENGTHEN IT. I THINK IT WAS BOUGHT AT A LOCAL PLACE NOW OUT OF BUSINESS CALLED ALPHA ELECTRONICS. I HAVE LOOKED OVER COAX AND ANTENNA AND ALL I HAVE FOUND IS A VERY SMALL CRACK ON THE SECOND SECTION FROM THE BOTTOM ABOUT 1 INCH ABOVE THE CONNECTOR. THE WEEP HOLE IS CLEAR AND FINDING NO WATER IN ANTENNA OR COAX. I HAVE RUN EVERY POSSIBLE TEST WITH ALL EQUIPMENT I HAVE AND CAN ONLY DETERMINE IT'S IN THE ANTENNA. ANTENNA ISN'T THAT OLD "ABOUT 3 MONTHS". I'M GOING TO TAKE IT TO MY LOCAL SHOP AND HAVE HIM LOOK AT IT FOR ME. IT MAKES A GOOD EXCUSE TO THE WIFE TO VISIT THE RADIO SHOP AND MAYBE BUY A NEW ANTENNA. I BOUGHT THIS FROM HIM AND KNOW HE WILL WARRANTY IT. SO FOR NOW IT'S MY HOME MADE DIPOLE ABOUT 30 FOOT HIGH HORIZONTAL