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Author Topic: raising wire antennas  (Read 667 times)
W1WN
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« on: August 31, 2009, 06:05:26 AM »

Was wondering what products or techniques were out there to raise an inverted vee in a tree about 50\' in the air.  thanks and 73\'s, Dave, w1wn
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WA2DTW
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« Reply #1 on: August 31, 2009, 07:11:22 AM »

EZ hang works well.   It is a slingshot combined with a spinning reel.
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W8CAR
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« Reply #2 on: August 31, 2009, 07:19:43 AM »

Dave, You\'ll get as many ideas as rice in China! I am \'tree rich\' and use the following methods. First, I shoot a brightly colored sinker over a nice limb with a sling shot and use my fishing pole to allow the line to reel out. Then I pull a brightly colored masons twine back over the limb-this way you can see if you really went where you intended. If the tree is really high I use a bow to launch an arrow with the line attached-use some solder wrapped around the arrow point so it comes to ground quickly and glides through the leaves. Once I\'m happy with the twine I pull some black covered line of 3/16 or 5/16 through the limb. I buy mine in full spools from Synthetic Textiles.

Trees move so I always allow slack in the antenna rope and also add bungees in the bottoms of both ends to allow for movement. I tie loops about 6 feet apart and then let the bungee take up some slack. Thus, the antenna rope can flex without breaking (although the \'rope\' once cracked welds on my tower because I didn\'t have it bungeed enough-lesson learned)

My experience has been if you go over the tree, enough branches will \'cushion\' the rope and allow for movement. If you go over a certain branch then you need to pay closer attention to tension on the rope!I rarely have had a rope failure or antenna failure with this method. I currently have a 160 L up vertically 70 feet and 100 over, full size 80 meter vertical and a 130 foot V @ 65ft fed with open wire along with many listening antennas and lower DPs in the trees.

Use good quality materials, don\'t overstress them and plan your install to be safe!! Wear safety glasses and watch fingers and use gloves to pull ropes.

God luck
Dan W8CAR
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K2ATX
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« Reply #3 on: August 31, 2009, 08:55:42 AM »

I have experimented with several solutions including the EZ Hang slingshot, pneumatic launchers such as the CV-19 and the Big Shot arborist slingshot.  I have even tried a large adjustable wrench or some similarly weighted object tied to the end of a rope, tossed over the desired branch.  However the results of the latter method were typically unsatisfactory, frustrating and in some cases downright embarrassing.  I prefer the Big Shot to anything I have tried so far.  While each one will get a line in the air, I have found the Big Shot to be more reliable over a broad range of antenna hanging scenarios.
I built my own pneumatic launcher from plans on the internet:
 http://www.antennalaunchers.com/csv19/csv19asm.html
The launcher performed as advertised.  Among the pros, the launcher looks impressive if you like that weaponized launcher look.  It is capable of launching its payload considerable distances and the unit is reasonably portable.  As for the cons, the unit operates on pressurized gas.  (I used the term gas rather than air as there are some who choose a CO2 solution rather than the more common bicycle pump or compressor methods to charge the unit.)  This requires another piece of equipment whether it is an air compressor of some sort or a bicycle pump.  In addition to the extra equipment requirement, there is a time factor to charge the unit and in the case of a bicycle pump a physical one as well.  This method relies on the use of lightweight line and a tennis ball or other projectile.  When launched into a tree, the branches can and often do provide sufficient resistance to prevent the projectile from reaching the ground, in some instances causing the projectile to become a permanent tree ornament.  On solution is to fire the line completely over the tree to a clear area on the other side.  This solution is not always practical or desirable.  One other fact worth noting is that the material typically used to construct these launchers, PVC is generally not rated for pressurized gas.  Over pressurization can result in a structural failure (the pressure vessel explodes producing PVC shrapnel).  Operation in colder temperature can increase the potential for this failure.
The EZ Hang and similar launchers employ a slingshot to launch a projectile attached to lightweight line into the air.
http://www.ezhang.com/
Another solution that works as advertised.  One clear advantage with this unit is size.  This is one of the most compact solutions for launching antenna lines available (My adjustable wrench is slightly smaller but we won’t go there).  In addition, this method does not require charging or pressurization; it is ready to go out of the box.  For the cons, this method employs a lightweight line and an even lighter projectile then the pneumatic method.
The Big Shot is an arborist’s tool and well suited for launching lines.
http://www.baileysonline.com/itemdetail.asp?item=21430
The Big Shot is my favorite method for launching a line into a tree or other support structure.  This system employs a robust slingshot head mounted on a fiberglass pole to launch weighted “throw bags” with a strong, lightweight, low friction line attached.  This unit is powerful and capable of successfully launching a line farther than the other methods I have tried.  I used the phase “successfully launching” referring to a launch that when completed allows an antenna to be pulled into the air.  When using other methods that employ the lighter fishing, type line and lightweight projectiles, the more line that deploys the greater the friction or drag often resulting an the projectile hanging somewhere out of reach.  Another feature worth noting is the line used in this system.  This line is the strongest of all the methods discussed here and is unlikely to fail under most conditions.  The fishing line methods can be subject to snags and drag possibly resulting in a broken line.  One solution often employed is to pull a slightly heavier line up first followed by the final antenna support line.  This is generally not required with the Big Shot method.  Throw bags are available in weights that range form 8 ounces to 16 ounces.
Not everything about the Big Shot is perfect as the size of this unit is the largest of those discussed here.  The head unit is actually compact however; the fiberglass pole is at a minimum four feet long.  There are two options for the fiberglass pole.  The pole is available as a single eight foot pole or a version is available that breaks down into two four foot sections.  Finally, this solution is a powerful, professional tool and as such has the potential to be dangerous.  It would be wise to be aware of the safety issues and use the proper caution when using this tool.
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W4VR
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« Reply #4 on: August 31, 2009, 12:59:11 PM »

The problem with using sling shots, bow and arrows, and the like to raise an antenna is that not everyone is a sharpshooter with these contraptions...it takes lots of practice to get it right.  When all else fails, hire a tree climber to hang it up for you.
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N2EY
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« Reply #5 on: August 31, 2009, 02:20:39 PM »

I made a slingshot launcher some years ago that has done the job very well. Its main advantages are low cost and small size. I have also used bow launchers and pneumatic launchers but they are much larger and more expensive.

I used a Daisy P-51 slingshot and a Zebco 404 reel. The slingshot is great but there are much better reels out there. What you want is an open-spool casting reel.

I use 1 ounce sinkers and 8 or 10 pound monofilament line. I paint the sinkers dayglo orange so I can find them again.

Eye-protection goggles are mandatory.

The sequence is:

1) Shoot light monofilament over tree.
2) Remove weight from end of monofilament and attach mason string or heavy monofilament (30 pound plus).
3) Reel in the light stuff to pull the heavier line over.
4) Disconnect the light from the heavy and attach halyard (I use 1/4" rope).
5) Pull up the halyard.

The best I have done with my launcher is about 75 feet. 50 feet is pretty easy with it.


A couple of pointers:

1) Safety always. Consider everything that can go wrong.
2) Be aware that in some areas a slingshot is considered a weapon, but in other areas it isn\'t. Same for a bow.
3) Do not try to shoot through a tree, shoot over it.
4) Have spare line and sinkers handy. Expect to lose some.
5) Take your time and don\'t expect the first shot to be perfect. It doesn\'t take a lot of practice to get good results but it does take some.
6) For temporary work, use brightly-colored line if possible. For permanent work, white (which will fade to gray) or black shows up less than a color.

Are you looking to put up a temporary antenna or a permanent one?

73 de Jim N2EY
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N1LO
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« Reply #6 on: September 01, 2009, 05:16:39 AM »

Hi Dave,

Lots of good tips for you so far. Rather than rehash, I\'ll offer some that haven\'t been covered.

Of all the line-launching solutions, I believe the slingshot to be the best compromise among all factors.

Your 50ft shot is relatively low and practically easy for even a small slingshot with just a little practice.

My rule of thumb for matching sinker weight and monofilament size is: multiply the weight in ounces by 10 to get the pound test of monofilament that works best with it.

An open-face reel does indeed have far less friction that the closed, Zebco types, but requires more care to keep the line from tangling before the shot, because the bail is wide open.

Super tune the performance of either type by liberally applying some light oil to the line. I like the silicone spray called "Reel Magic". It\'s far easier to spray the line in stages on the reel with an open-face type. This reduces friction in the reel and on the line as the sinker tries to pull it down through the tree.

What goes up may not come down...for a while!

It\'s easy to make your own launcher, starting with a slingshot that has a wrist brace. Hose clamp a piece of 1/2" pvc to the brace long enough to extend in from of the yoke a couple of inches. Then, hose clamp a 1/2" coupling to the mount on the reel. Now you have two-upped the Easy Hang with a lower friction reel that also detaches for stowage.

For a quick disconnect rig, tie a permanent loop on the end of the monofilament ("perfection loop" knot) that\'s big enough to pass the sinker through. Pass the loop first through the eye of the sinker, then over the body to create a simple choker that\'s easy to remove.

And finally (sorry - getting long), a critical tip: Do *NOT* try to reel a bad shot that\'s still in the tree with the sinker still attached! Let the sinker hit the ground and take it off before reeling the line back.

GL,

--...MARK_N1LO...--
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