I Introduction
II Antenna choices One man's Opinion
III Climbing Trees leave it to the professionals
IV A Few Simple Rules
V Non climbing techniques what works, what doesn't
VI The tree tower a stealth technique
VII Summary
I Introduction
Like being too rich or too thin trees pose an interesting dilemma for the radio amateur. You CAN have too many, but in general it's better to have some than none. The intent of this article is to outline some antennas which have worked, and which I continue to use after 40+ years as a ham and to describe some techniques for putting them up.
When I moved to Vermont, in 1995, I bought property with several acres of mature hemlock and white pine forest. My landscape architect considers 60' hemlocks to be weeds. I consider 130' white pines as old souls and antenna supports. There's a kind of symbiotic poetry involved with hiding wire antennas at heights where they kick butt, are almost invisible, and inevitably produce the question, 'How did you get that wire up THERE? .
Before starting this report, I polled the Frankford Radio Club for their experiences with rope launching systems. Suffice it to say that there are advocates for alternate techniques, and matters of personal taste and skill will alter your viewpoint. Without apology, I will describe what has worked for me, and what hasn't.
As you read this opinion piece, keep in mind that every situation is different. What works for me may not work for you. Available space,
Ground conductivity, height of trees and location of house are all conflicting factors, which will lead you toward your own compromise.
The only certainty is that antennas in trees ARE compromises. The best antenna you can erect is high and in the clear; trees represent something else.
With some experimentation, you can usually come up with something workable.
II Antennas that work
This part is included at the editor's request, but it's really beyond the scope of a short piece. There are as many wire antenna types as there are published pages of antenna information. Read the book. Start with the ARRL Antenna Handbook (p. 22 1), and work from there. What will work on your property may be unique.
N2NT worked successfully with single band wire antennas in the woods behind his condo, several years ago. Two half waves in phase produce gain, and are quite effective. If you're looking for an idea, you might ask Andy.
K4AO, Ron, uses rectangular loops exclusively. At this writing, I can't find the file with those references; however, Ron gives a good account of himself in most contests, and his arrays don't require super tall supports.
My personal preferences lean toward the simple. Since coming to Vermont, I've experimented with very few antenna types. This is largely because I'm plagued with too MANY trees. The clear spaces in between are somewhat limited, and what I've put up has worked.
Elevated Ground Plane Verticals: I have had full sized GP's up for
160, 80, and 40, for at least five years now. They work. The one on 40 is
150' above the house, at its base, and fed with 300 feet of 9913. It's at least
10dB better than anything else into Asia, at 40m greyline.
Each of these GP's has three elevated radials, which snake through the trees, just above deer antler height. A mama moose got snagged in the 160 last
Fall, so I obviously didn't get it quite right. Um, excuse me madam moose, but
May I have my antenna back? She got untangled after being left alone for a bit.
Good thing I used soft drawn copper wire, which she could break.
The 1.8 and 3.5 GP's are really one dual band antenna. I used 450 ohm feedline for the first 65' of the radiator, and continued with soft drawn copper above that. Three radials for each band run out through the trees, as previously described.
This antenna was fabricated in a couple of hours, and thrown up quickly, to work the ZL9CI expedition. While I didn't work them on first call, I DID get through, and got a decent report.
Grounding systems for vertical antennas represent an area where there has been some evolution in the last 20 years. There are decent discussions of the history in the literature. Let me say, however, that elevated radials work.
I would not contemplate burying a ground system again.
Most of the Bell Labs work done on vertical antennas in the early 30's supported the 120 buried, 1/4 wave radials, which have been common in the AM broadcast industry. It was sometime in the 70's when amateurs who were also professional Consulting Engineers, experimented with a small number of elevated radials, in lieu of the 120 buried.
What they discovered was that the further the radials are from the lossy dielectric earth, the more efficient the antenna became. Four elevated radials at 10' were reported to be the equal of 120 buried radials, at 1.5 MHz. Most of their prototype work was actually done at 1.8 MHz, and scaled up for the lower frequency.
How well a vertical or elevated GP works out at 12,000 miles depends as much on the shape of the terrain, and the conductivity of the earth out in the first reflection zone.between 1/2 wavelength and 1 wavelength away depending on your height above ground. As a practical matter, this is out of our control, anyway. Overall efficiency of the antenna can be improved by getting as high above ground as possible. As for the 'Brewster Angle' or refractive effects of the earth, which control low angle radiation.you're at the mercy of your environment.
The published reports about vertical performance tend to be clouded by close in performance, and idealized installations. I've found that a 1/4 wave 7MHz GP is excellent, when the base is at 60', and the 4 radials slope downward at 45 degrees. I was routinely able to work into SE Asia and western Australia at greyline running an SB220 with perhaps a kw out.
For the record, verticals are NOT good receiving antennas on the low bands. They're OK on 40, but f/b rejection of stateside competition would help in a contest. To seriously chase DX, or for contesting purposes on 80 and 160, you MUST have a separate low noise receiving antenna. Beverages, Pennants and Ewes all have their advocates. I won't go into them here, other than to strongly suggest that you study the available literature if you're going to be serious on 160 and 80.
Single band dipoles: For single band use, the common dipole elevated 1/2 wavelength at its center works well. Lower installations favor higher angles. On 40 meters, you won't be DX competitive below 65'. You WILL produce lots of stateside QRM, though, and earn the enmity of your friends. You will probably also make yourself nuts calling long haul DX that you can barely hear, and who doesn't stand a prayer of hearing YOU, at all. On the other hand, you WILL be able to work the bulk of the EU stations just fine. That could add a few hundred K to your score.
Things are a bit more mixed on 80 and 160. It's hard to get an antenna up a half wavelength, for one thing.so folks tend to favor verticals. Then too, there are 'high angle nights ..where a horizontal wire at a hundred feet (that's a low antenna at those frequencies) is better than a full sized vertical.
Multiband dipoles: There are lots of types here..and they inevitably have inherent compromises. Tuning them can make you nuts, for one thing.
I experimented with a double sized G5RV for 160, 80 and 40, last winter.
It was up about 85 feet, and in the clear. And it played quite nicely for most domestic and EU DX. It wasn't as good into Asia as my 40 meter GP, by
15 20 dB. It had several merits, though it was simple to put up, tuner friendly, and quite flexible. Gave a good account of itself on the higher bands, as well.
Carolina Windom: Strictly speaking, not a windom, but an off center fed dipole.
It's worth looking into. I've used one extensively in Vermont.
Radio Works sells these and loops in various configurations. I have had a 160 meter CW160 for several years now, and am quite satisfied with it as a general purpose antenna. They come with copperweld wire, which I find to be unworkable for single handed antenna erection. It LOOKS for an excuse to tangle! Because of that, and my need to snake the wire THROUGH some trees, I switched over to #14 soft drawn copper, with black insulation. You can buy this at home depot for 10 bucks a 500 ft. spool.
Take note that soft drawn copper WILL extrude. As it does, it hardens, becomes brittle, and WILL break. My antenna came apart in 20F weather, and when the feedpoint balun hit the ground, the toroid within turned to small fragments.
My second one is made from a 256 conductor #12 insulated copperweld that Radio Works sells. It's pliable and easy to work. You can tie knots in it. And it's strong. I would not use anything else, for an antenna I wanted to leave up for any period of time. That's an unequivocal recommendation.
My CW 160 has been up since 1996, at approximately 100' in some handy white pines. This is a 'low' antenna for both 160 and 80, but seems to work ok. I'll go into launching experience later, but one performance anecdote is worth retelling:
During the CQ 160 contest in 1997, near my sunset. Coming in to the shack, I copied a JA7 with a really loud signal.at that time of day, it had to be long path. My Titan amp needed 3.5 minutes of warmup..so the tension mounted, as other stns started to find this guy..the competition built. The signals were up and down.and finally the amp's warmup timer completed its cycle.
I jumped on the key, dropped my call in twice..and the guy came back, giving me a 449. Only then did I notice that in my haste, I hadn't bothered to
take the amp out of standby. Go figure. He must have had a super receiving antenna system. Or, timingis everything. In my humble opinion, the Carolina Windom is worth consideration. But unless you're a masochist, you'll be happier spending the money on the super wire.
Loops: I'm no expert here. The delta loops I've had up on 40 have been mediocre performers, at best, when compared against elevated GP's.
Radio Works has produced a loop for 80 and 40, which they call a 'superloop'. We tried one of these at W1MOO Field Day 2001, and it gave a decent account of itself on domestic paths. No idea how it works long haul.
If you've got a small site, however, it might be worth trying one of these, just to add 80m EU, Carribean and SA mults.
Rectangles: I mentioned K4AO previously. These antennas are low loops, which have attributes similar to vertical arrays. The vertical elements radiate,
And the horizontal portions link them together. Radiation from the horizontal sections cancels out, producing an effective low angle radiation system.
There are issues with local ground, I'm sure, depending on height above earth, and conductivity. You're really at the mercy of your earth, and available antenna supports. This merits more investigation.
III Climbing Trees Leave it to the professionals
First of all, if you can climb it, it's probably not high enough. Second of all, consider that falling from a 40 or 50 foot Maple probably won't kill you it'll just turn you into a quadraplegic. Not only will you not be able to enjoy radio using the antenna you just hung, you're likely to become a burden to friends and family.
If you're foolish enough to contemplate climbing make sure your long term disability insurance is paid. And maybe take a second to contemplate what it'll cost to take care of you for the rest of your life.
For heights up to 45', you can rent a bucket trailer from your local equipment rental company for about 150 bucks for the day. I recommend it. Not only can you install a pulley in the tree easily, you'll have lots of time left over to prune things out so the tree looks good, and wires don't get snagged so easily. Or, pay an arborist. They're equipped to do it safely, quickly, and fairly inexpensively.
IV A few simple rules
1) Use pulleys in each tree. These can be pulled up with a rope, or attached to a hook/eye system, if an arborist installs it.
2) Use a closed loop halyard through each pulley. That way you don't lose the end. Tie a knot. Tape the ends.
3) Visit Rope Rope, and get 1/8 olive drab Dacron line. It has a breaking strength way beyond anything you'll need. (600 800 lbs.) Heavier line is more visible, and harder to pull up.
4) Hang a counter balance from the halyard, (sash weights work well), to provide a measure of give when the wind blows. The ARRL antenna book has workable suggestions.
V Non Climbing Techniques Tools for getting wires in trees
Spinning rod: I've used this with minimal success, over trees at perhaps 50 feet. 25 20lb monofilament line, and 2 oz. Sinker. I've lost more sinkers than I care to recount, tangled more line and broken more windows than I want to admit. If you can't put a lure in a peach basket 100' away every time.don't even think about trying this system. You won't get the antenna where you want it, and you'll waste a lot of time learning what you can't do. You might get good at replacing broken windows, though.
Wrist Rocket: These provide a really neat solution for snaking wires down cable ways, under elevated floors, and across attics. They even work for trees up to 50 or 60 feet. They're compact, and provide a neat means for handling the fishing line.
I have heard stories about these being used for trees in excess of 100', but I don't believe them. It MIGHT be possible to throw a 1 oz weight over a tree that high, pulling 8 lb test line. But will a one ounce sinker carry the line to the ground? Then consider that you have to pull 20lb test up 100', overcoming friction with the branches.and then heavier string.and THEN the 1/8 rope which I recommend. It's a lot of work.
In my experience, you need 2 3 ounces to overcome friction and get the line to the ground. The guys who say they've done it over 100' haven't ever been at 100' and looked down. Those are maybe 75 foot trees they're playing with.
The picture shows a wrist rocket with a Johnson closed face spinning reel. This system works extremely well at 50' and below, and particularly in dense forest, where other techniques are compromised by the foliage. My 7MHz GP was hung using this.
In another picture, you'll see a tree we measured at 120', as seen from the launching position. This Wrist Rocket failed to put a one ounce weight anywhere near the top. Period.
Bow and Arrow: For high trees, this is my weapon of choice, when combined with a 'fishing arrow' and reel.
It may not be ideal in close, suburban neighborhoods. It may even be illegal in some jurisdictions. I recommend you check with local authorities before you start shooting! Make absolutely certain that your downrange path is clear and secure, that all pets, neighbors, and working partners are out of the path, before you loose any arrow.
There is a lot of subtlety involved in configuring a successful launcher. What you want is a 25 35 lb pull, recurve bow, and 25 lb test monofilament line. In my experience, compound bows will NOT work, even at the same power, because they produce their power much more quickly, and will tend to break light line.
Monofilament line has lower friction than other types, and will slide over branches more easily. Ice fishing line is braided, and has high breaking strength. It tends to be too heavy, and requires a heavier arrow to work it to the ground, and more powerful bow to get it over the tree.
The fishing arrow pictured is made of fiberglass. It's fairly heavy, and the nock has a hole to accommodate the line. If yours has a screw in tip, replace it with a bolt. If it's just glued on, use a file to round off the point, so it's as dull as you can make it. If you can find a stun ball point, sometimes used for plunking squirrels, that would be a better choice. Get your sporting goods shop to replace the tip on the arrow, if you can.
The arrow in the picture wasn't dull enough, at first. I stuck it dead center
In the branch I was trying to clear at 120' and it was three months before it shook loose.
I recommend purchasing Krylon fluorescent orange or pink paint, and painting the arrow. The same arrow spent another three months in the snow, completely invisible, before I found it. Having it stand out from the trees will make it easier to work the arrow to the ground, after you've shot it through the tree. Or find it, if you break the line.
The first picture shows a typical 'open face fishing reel. This is really just a spool, which screws into the balance point on the bow. It works fine, if you're shooting at fish 20' away. If you have to wind 200' of string back on, after you've just missed the branch you wanted, it gets more than a little tedious. 35 lb. bow courtesy of YCCC and WJ1Z.
Bob uses ice fishing line with this system, and gives a good account of himself. He doesn't need an intermediate string, but sometimes finds himself hung up in the tree, where the weight of the arrow isn't enough to pull the string over the branch.
The second picture shows the 25 lb bow that K2BMI and I share. The open faced spool was taped to the bow with electrical tape. This year, I replaced the spool with a 'Game Tracker . This system spools out 15 lb test polymer string in a very predictable fashion. Once the arrow is over the tree.all you have to do is tie it to the rest of the line, and gently pull.
I find that this system requires an intermediate string, because the weight and friction of 200' of 1/8 Dacron is more than 15 lbs. The gametracker string broke 3 or 4 times, mere inches from my grasp, before I gave up and went with an intermediary. A typical gametracker cartridge provides 2500' of line.and it's disposable, so you don't waste a lot of time winding it back up again.
In the last picture, you'll see a spool of the 1/8 Dacron o.d. line that I buy from Rope Rope, and my method for managing it. Home Depot sells the orange spools for handling extension cords.
Trees Fight Back:
A rope or wire laying over a branch will be covered in sap within a year. You may not be able to pull it back out, once the tree decides to grab hold. In my first installation at 100', I used 1/4 Dacron rope. 2400 lbs breaking strength. It stuck fast. Wound up fastening a turning block at the base of the tree, tied the rope to the trailer hitch on my jeep, and pulled away slowly, in 4 low. I pulled down a branch that weighed over 500 lbs, with the rope still held fast by the pine sap.
VI The Tree Tower A stealth technique
It is possible to use a tree to hold up a tower. Rohn 20 or 25 can work for this application. Loops of rope or chain go around the tree, and fasten to the tower, which snakes through the branches, and aligns with the main trunk when possible.
I've seen such a system holding an A3 10' above the top of a maple tree, at 50'. The tower itself was painted with olive drab and black camoflage, and blended in well with its surroundings. The owner claimed that it worked reasonably well.
Installation obviously required some climbing of the tree, at first. For reasons previously explained, I recommend use of a professional for that task.
Getting the A3 through the top of the tree, assembled, and on top obviously required more effort than normal. The owner told me he'd brought up the individual elements and assembled the beam topside. Normal tower climbing techniques, including safety harness, apply and make this a relatively safe system.
VI Conclusion:
If cutting down all your trees and planting towers isn't in your future, hanging antennas in the trees might prove to be a viable option. It's kept me on the air for the past 5 years.
For smaller trees, in the 40 60 foot class, a number of techniques will work, including slingshot, Fishing rod, and Bow and Arrow. For high trees, in the 100' and above class, only the bow and arrow appears to have the power and directional control necessary for the job.
As a parting thought, at least some of the time, you won't get the arrow over the branch you want. Think twice before you pull it back over the tree, toward you. That arrow is tumbling, but will steady itself before coming to earth. Remember, it's coming in your direction!
In my particular case, a friend was helping me.pulled the arrow back, and nailed my flat roofed house. Try explaining THAT to your local roofer when there's three feet of snow on your roof!
