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Author Topic: Mounting Antenna on Tree?  (Read 701 times)
KC2NLT
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Posts: 92




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« on: November 07, 2017, 12:11:32 PM »

I’ve got a few tall trees in the backyard, somewhere in the neighborhood of 70 feet.

I’d like to mount a couple of antennas, but I’m not sure of the best way to safety climb that high. 

A bucket lift like some utility companies have would be perfect, but I can’t think of anyone that offers such services.

Any ideas?
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K0UA
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Posts: 1380




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« Reply #1 on: November 07, 2017, 12:47:20 PM »

I’ve got a few tall trees in the backyard, somewhere in the neighborhood of 70 feet.

I’d like to mount a couple of antennas, but I’m not sure of the best way to safety climb that high. 

A bucket lift like some utility companies have would be perfect, but I can’t think of anyone that offers such services.

Any ideas?

What kind of antenna?  I have plenty of wire antennas in trees.  A 3 element 20-10 tribander would be a heck of a problem.  Even getting a vhf vertical in one would be very problematic.  Trees are great for wire antennas, but not much else.  No bucket trucks needed to get a wire up in a tree. Either slingshot (cheap and small) or I use my pneumatic launcher now, as it is more accurate and less effort and time. Soe have used bow and arrow successfully, but be careful. You can use a throw bag if it isn't too high. Lots of ways work.  But I got the impression you were thinking of something made of aluminum..  Let us know.
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KC2NLT
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« Reply #2 on: November 07, 2017, 01:13:46 PM »

It’s going to be 2 antennas; a dipole and a vertical with ground plane. I figured I could create a small platform out of wood and then secure that to one of the branches or the tree top. But I’m no mountain climber Smiley
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K6BRN
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Posts: 462




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« Reply #3 on: November 07, 2017, 01:21:36 PM »

There is no perfectly "safe" way to climb a tree, and if you haven't acquired the skill to do it when younger, I don't advise doing it once you are older.

That said, me and my family are all tree-climbers (as opposed to tree-huggers) Smiley

The most challenging antenna I've put up in a tree is a large vertical in a 75 foot pine tree.  It survived several rough winters in New England, including massive ice and heavy wind with major tree sway, before I moved and had to take it down.  I would NOT try to do this with a large Yagi.

Pine trees are great for antennas - usually easy to climb and very straight.  Right now I have an EFHW-80102K whose mid-point is about 30 feet up in a pine tree in my back yard on the West Coast.  I simply put a ladder against the lower branches to get into the tree and climbed the rest of the way up - not much to it.  At the 90% height point, I installed an eye bolt into the trunk - does not hurt the tree at all - and a tool strap to loop the wire antenna through to give the loop a compliant mount with a gentle radius.  The two wire end points are anchored to the eaves of my home to form a horizontal V antenna that is largely omni-directional.  Works great and I using it on 30M/FT-8 as I type this.

On the East Coast, where I also maintain homes, I string wire antennas between trees using a similar technique, at heights of 20-30 feet.  In that case, between Oak trees, which tend to have branches that start far from the ground, I again use a long extension ladder to get to the lowest branch.  Climbing is trickier.  And in those wire antennas, where I have more room, I tend to put them up as straight (nearly end fed) runs  whose perpendicular radiation angle is mostly 60 degrees northeast.  Provides good coverage of Europe, the West Coast and Australia/New Zealand ( the pattern is broad).

Most NON-TREE CLIMBERS use some sort of line launcher, from a fishing pole to a compressed air gun to "launch" a pilot line over a  high branch of a tree and then use it to pull up the end of a wire "sloper" antenna - often an EFHW antenna fed from the bottom end, at angles ranging from 45 degrees to almost 90 degrees.  These are usually temporary installations, but some users report they've had theirs up for more than a year with few problems.  With this approach, how stable the top antenna mount is , is in large part luck.

Whatever you do, be careful and stay safe.

Best Regards,

Brian - K6BRN
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K6BRN
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« Reply #4 on: November 07, 2017, 01:44:36 PM »

Regarding building a platform high up in a tree to mount a vertical with radials, I do not recommend this approach.  Generally, as you go higher in the tree, the trunk and branches become thinner and less able to support a platform or "tree house". 

It's better to build a mount into the main trunk (if possible) by prefabricating/prefitting an antenna mount on the ground out of pressure treated 2x4 lumber and antenna brackets.  Then take just the mount up into the tree and prefit it to the mounting location, including making measurements of any shims needed to keep it approximately vertical in the X direction, and premark alignment in the Y direction to achieve the same goal.  Next, attach the shims on the ground and pre-drill mounting holes for 3 inch x 1/4 inch or thicker lag bolts.  Once this is done, go up the tree again and pre-drill the mounting holes into the tree trunk using the mounting you've built as a guide.  Once this is done, go back down the tree with the mount in hand and attach (at least) the base of the vertical antenna to the mount.  In my efforts, I actually pre-assembled the antenna and mount on the ground and slid it vertically through the branches and into position.  Holding the antenna and mount over the pre-drilled holes in the tree trunk is pretty tricky.  I had a friend come up with me and ho;d it in place for the 30 or so seconds required to start two of the lag bolts.  This is by far the most dangerous part of the operation, as the antenna whips around in the wind and as the tree sways.  I strongly recommend using a safety harness if you do this.  The radials, if wire, than have to be draped horizontally down the tree branches.  This is a real chore, is less than optimal, and tends to be unstable as the tree moves and grows.  Bottom line:  Its a LOT of work, a lot of physical risk, and for the most part, not worth it.

Its FAR simpler and just as effective to simply anchor one end of a wire antenna high up in the tree and forget the tree mounted vertical altogether. The tree mounted vertical will not buy you much more than the wire (suggest and EFHW-4010 or -8010 - see the reviews).  Been there, done that.   Just my opinion, based on actual experience.  Perhaps someone else has a better, easier, more effective and safer way to put a big vertical up in a tall tree.

Brian - K6BRN
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KD0ZGW
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Posts: 717




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« Reply #5 on: November 07, 2017, 02:22:05 PM »

ask a local tree guy.  mine charged me $150 to raise and lower my tilting tower; many hundreds of dollars less than a crane guy.  his truck has a 60' reach and a 1000 lb capacity.

hope this helps.  don't fall out of a tree.
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KW4GT
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Posts: 72




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« Reply #6 on: November 07, 2017, 03:56:54 PM »

What type of groundplane antenna are you thinking of?  I have a wire groundplane on 40 with the top at approximately 60 feet and it works quite well.  It has 4 wire radials sloping down at maybe 30 degrees or so, I've read that elevated verticals can use as few as 2 radials with only slight degradation of the pattern so long as you're able to keep the radials symmetrical.

I use a slingshot with 50 pound mono fishing line, then pull up paracord with that.  I view all my wire antennas as temporary, I'm always experimenting anyway, but they've survived tropical storm force winds with no ill effects.

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“Anti-intellectualism has been a constant thread winding its way through our political and cultural life, nurtured by the false notion that democracy means that 'my ignorance is just as good as your knowledge.'” ― Isaac Asimov
KD6RF
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Posts: 573


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« Reply #7 on: November 07, 2017, 04:32:45 PM »

I can throw a weight with trailing light weight line up about 25 ft high.  My fast-ball apparently ain't what it used to be !!!

Beyond that, I use a cheepo crossbow ,which may be problematic if you have close neighbors !!!  Huh  If one get away from you , it can easily land several hundred yards away.

It's easy with the crossbow to get the line (which pulls  the rope which holds the pulleys / insulators that the wire is suspended with).  I have an inverted-L up about 50 ft in two of the trees here.  Crossbow could go up quite a bit higher if desired.


Thrown about 24 ft high ===>





Overkill-Crossbow up about 50 ft high, then over to another tree at 50 ft high ===>



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VTenn Antennas
Bay Area Technical Equip Rental and Test Range
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KM1H
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Posts: 2508




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« Reply #8 on: November 07, 2017, 06:04:32 PM »

In my 20-40's Ive climbed several 70' pine trees to install antennas including a full size 40M ground plane with radials tossed over the branches; plus a rotator, long boom TV antenna and a 13 el 220 mHz yagi above it. That survived 10 years here in NH until I moved to this hilltop.

A tree guy around here charges $100/hr with his bucket lift and is very quick/efficient in thinning the trees here since at almost 77 Im no longer interested in being a tree ape Roll Eyes Grin

Carl
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