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Author Topic: Tree antenna??  (Read 1721 times)
W1TLD
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Posts: 41




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« on: February 02, 2013, 11:25:42 AM »

I have a nice tree in my front yard.  it's approx 40 feet tall.  I'd like to hide a vertical all band antenna in it.  I'd at least like to be able to use the 40 thru 6 meters.  It must be able to be mounted in the tree and not need an extensive ground system.  Our HOA restricts outdoor antennas, so the idea is to hide it well enough that no one will see it.  That said:  Anyone have an antenna they would recommend for this?  I will be using a tuner that will most likely be in the shack.  Ideally, i'd put it near the base of the antenna, but....Thats is going to e very difficult in this situation.  I'd also like to be able to hook all of this up to an amp eventually.  Thanks for your recommendations and ideas!
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VE3FMC
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« Reply #1 on: February 02, 2013, 12:14:10 PM »

I have a nice tree in my front yard.  it's approx 40 feet tall.  I'd like to hide a vertical all band antenna in it.  I'd at least like to be able to use the 40 thru 6 meters.  It must be able to be mounted in the tree and not need an extensive ground system.  Our HOA restricts outdoor antennas, so the idea is to hide it well enough that no one will see it.  That said:  Anyone have an antenna they would recommend for this?  I will be using a tuner that will most likely be in the shack.  Ideally, i'd put it near the base of the antenna, but....Thats is going to e very difficult in this situation.  I'd also like to be able to hook all of this up to an amp eventually.  Thanks for your recommendations and ideas!

I have a 17 meter vertical mounted up into a maple tree. Now at this time of year it is visible, no leafs on that tree.

Your idea will work, however if you use a mult iband vertical or even if you use a straight aluminum tubing vertical you are going to need ground radials. Otherwise that antenna will not perform very well.

Mounting the tuner at the base is the way to go if you are going to use a single element vertical on 40-6. But if you plan on running an amp you need to make sure the tuner will handle it of course.

Others will weigh in with what length of tubing you should use to cover those bands. These 43 foot verticals seem to be the popular choice these days for multi band operation but that length won't work for you.

How do you plan on mounting it in the tree? You are going to need some sort of mast to mount it on. My 17 M ground plane vertical is mounted 16 feet off the ground on fibreglass military mast that sits in a tri pod. Then it is tied off o the lowest tree branch for support. Antenna works quite well for what it is. I have worked JA's Europe etc with JT65 at 15 watts. Well I did until the high winds ripped off my thing magnet wire ground radials this past week.  Angry Need to repair those and I will be back in business.

It will be interesting to follow this thread and see what others suggest for you.

Good Luck, Rick VE3FMC
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W6GX
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« Reply #2 on: February 02, 2013, 12:39:16 PM »

What about stapling a wire to the tree truck or use a vertical dipole that doesn't require ground radials?

73
Jonathan W6GX
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W4VR
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« Reply #3 on: February 02, 2013, 12:46:00 PM »

You could install a random vertical wire in the tree and secure it to one of the highest branches...sloping it down toward the trunk of the tree.  You would do best by using an auto tuner at the feedpoint if you intend to used it on more than one band.  You should also bury a ground screen (radials or wire mesh) under the feedpoint to reduce your ground losses.  I use a tree to support my 160 meter inverted-L and it works well.
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W1JKA
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« Reply #4 on: February 02, 2013, 01:04:27 PM »

   Base hiding suggestion only: My 33 ft.vertical(wire) also in maple tree about 10 ft. out from trunk drops directly down into the top roof of a medium size bird house that is mounted on a 5 ft. high 4 in. post,tuner is inside bird house and accessable by door I built,it's on my side lawn and nobody except me and my xyl knows its an antenna.
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W3HKK
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« Reply #5 on: February 02, 2013, 01:53:03 PM »

Id go with a 40m loop.  Around 135 ft in circumference.  Any shape that fits.  Vertical or tilted.  Try ladder line feed to a tuner. Convert the  ladder line to 52 ohm coax thru a 4:1 balun just outside the house and run coax into the tuner.  You get 40m and all  multiples of 7 mhz. 

I use  loops all the time in contest operations.  Cut them for the lowest frequency you need and work all multiples above as well.  Mine have been horizontal, vertical, and tilted.  Many have laid over multiple branches and through the leaves.  Use insulated wire to be on the safe side,  a 500 ft spool of #14 electrical  pvc jacketed wire  can be had at  Home Depot.

No radials.  No ground.  Hang, feed, and  tune it with an in the shack antenna tuner. 

Good luck.
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K3VAT
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Posts: 701




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« Reply #6 on: February 02, 2013, 07:11:18 PM »

Tree-mounted verticals do work.  If you really want to go stealth and multiband, then I recommend you build it with black insulated wire and use Unadilla traps for your favorite bands.  You'll need at least some kind of radial field for this antenna to operate with decent results, say a dozen or so radials spread in a circle if you can get it.

Pick a fairly heavy gauge insulated wire like # 12 or # 10; you don't need to staple the wire to the tree, in fact, you want a bit of distance between the tree and the wire to reduce any possible loss, especially when it rains.  Aluminum could work if it is thoroughly camouflaged but often tree branches get in the way of a straight run like telescoping aluminum sections.

W3HKK: Bob, he lives in an HOA antenna restricted community and needs to have a completely stealth operation so I don't think that the loop would work.  Everything must be close to invisible including any supports, insulators, coax, etc.

Terry: if you'd like to see a couple of photos of my stealth 40M/80M vertical drop me an email.  GL, 73, Rich, K3VAT
(k3vat at arrl dot net)


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K0JEG
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Posts: 639




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« Reply #7 on: February 02, 2013, 08:41:54 PM »

I'm using a tree mounted vertical in a pine tree next to my apartment. It's about 22' long with 2 19' radials (about 10 feet off the ground). Fed with a 4:1 UNUN, it works fairly well, but not great. I get a good match on 40-10 meters. The radials are visible but not offensively so (one attaches to the building with a screw, the other to the mount for a basketball hoop with a dogbone and a stiff wire). I think in a pinch they could have been sloped down from the unun and attached to branches, but I had permission to put it up so I wasn't worried about stealthyness. The tough part was getting it into the tree, up high and attached in a way that it wouldn't fall out. The easiest way I found was to borrow a bucket truck from work and use a P-hook screwed into the tree, but it still took about an hour of screwing around trying to keep the wire close to the tree trunk.

http://www.alliedboltinc.com/product/3-3/4-inch-P-HOUSE-HOOK~921.aspx

I think the next time I do this (which may be in a few months), I'm going to just get an LDG telescoping vertical and run it up next to the tree trunk and hope no one notices. I also think it would be better to use a tuner at the feed instead of an unun, but sometimes it's not that easy to do.
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KD8GEH
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Posts: 464




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« Reply #8 on: February 03, 2013, 05:54:45 AM »

You can rig a nice tree vert pretty easy. DO NOT staple to the tree. Traps are good if u can get away with them. position the wire away from trww as much as possible, String some  raduals for the preferred band and ur in bussiness.

Dave
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VE3FMC
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« Reply #9 on: February 03, 2013, 06:03:57 AM »

   Base hiding suggestion only: My 33 ft.vertical(wire) also in maple tree about 10 ft. out from trunk drops directly down into the top roof of a medium size bird house that is mounted on a 5 ft. high 4 in. post,tuner is inside bird house and accessable by door I built,it's on my side lawn and nobody except me and my xyl knows its an antenna.

That is a pretty slick set up, love that bird house tuner.  Grin What did you use for ground radials?
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W1JKA
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« Reply #10 on: February 03, 2013, 07:14:48 AM »

Re: VE3FMC
     Only 3 33ft. radials in a zig zag pattern,not enough room to stretch out straight.Not the most efficient,but a good back up antenna for my horizontal wires.Radials themselves are cheap electric fence wire from Agway.
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K5LXP
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« Reply #11 on: February 03, 2013, 09:35:35 AM »

Zig-zagging radials does not change their effective length.  More radials, even if short, are a better way to go. 


Mark K5LXP
Albuquerque, NM
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