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Beginner ham antenna questions
- Thread starter bhayles
- Start date
A "stopper" for the spreaders, one in each wire, and a stopper going the other way for the monofilament I'm using to extend each bands wire to the tree, keeping everything pointed in the right direction.
I know that every inch counts toward length of each wire, from its tip to the feedline connection, including any used to make the knot and the distance from the tip of the line through the copper sheet that connects each band to the feednine, so I'll allow for the extra wire to make the knot. I just wanted to make sure the "sorta one loop coil" of a knot wouldn't cause an issue.
I know that every inch counts toward length of each wire, from its tip to the feedline connection, including any used to make the knot and the distance from the tip of the line through the copper sheet that connects each band to the feednine, so I'll allow for the extra wire to make the knot. I just wanted to make sure the "sorta one loop coil" of a knot wouldn't cause an issue.
Purists will say yes it matters. realists will say it will never be noticed. I tend to form a loop in the end and connect it too a string or rope sometimes but I usually use an insulator first.
I started to make some 3" insulators from PVC, but then I thought about it and decided not to. My thinking was:
1. The closest any of the wires will be to the tree is about 10 ft for the 80 meter band, and it will be connected with 50# test monofiliment, already a good insulator.
2. An insulator adds two connection points...wire to insulator and insulator to monofiliment...rather than just one...the wire to monofiliment connection. As each connection is a possible future point of failure I thought only have one connection rather than two was one more failure opportunity removed.
Am I wrong in thinking the 10 ft minimum of monofiliment is adequate insulation?
Sort of depends on what band or frequency the dipole is cut for, but unless it's something above ten meters it shouldn't cause any detectable problems.
This assumes just an accidental overhand knot. Now, if you were to put in a Turk's head, or a bowline on a bight, or a sheepshank, YRMV.
What's the function/reason for the knot?
OK...another question...
I'm wanting to put this antenna up with the center collector for the fan dipole at ~70 feet. I have two perfect trees to string it between that give me plenty of height. But...
I am having trouble finding someone to climb the trees. In my younger days I'd have done it myself, but I don't have it in me any more.
How high is high enough? The trees line up N-S so the antenna is going to radiate more E-W, which is good. I am at 1650 ASL which is also good, and everything higher that me in mostly due south or ENE, so nothing really in the way. I can get my hands on a 40 ft ladder, and then reach up another 5 ft to get the screweyes in the trees. That would put the ends of my 80 meter wires at about 30 feet and the ends of my 10 meter wires at about 25 feet.
Good? Great? Marginal?
I'm wanting to put this antenna up with the center collector for the fan dipole at ~70 feet. I have two perfect trees to string it between that give me plenty of height. But...
I am having trouble finding someone to climb the trees. In my younger days I'd have done it myself, but I don't have it in me any more.
How high is high enough? The trees line up N-S so the antenna is going to radiate more E-W, which is good. I am at 1650 ASL which is also good, and everything higher that me in mostly due south or ENE, so nothing really in the way. I can get my hands on a 40 ft ladder, and then reach up another 5 ft to get the screweyes in the trees. That would put the ends of my 80 meter wires at about 30 feet and the ends of my 10 meter wires at about 25 feet.
Good? Great? Marginal?
You haven't seen how I make my terminations.
I make a basic fisherman's clinch knot in the end. I have never had one let go yet.This is 12 gauge wire (green wire) and with smaller gauge the wire will break before the knot will fail.
Have you thought about trying something like a Sling Shot or as I prefer a Noodle Rod fishing pole. (7 ft fiberglass rod/very flexible but very strong)
I use a cheap large Salt Water type spinning reel(Catfish reel Large spool) filled with couple hundred feet of 90 lb. string. Large bell sinker or torpedo sinker on the end.(couple ounces or bigger)....Use string, much more flexible than fishing line. Mono-filament line has one issue IMO once it is nicked, even slightly it will fail. Thus pulling it over tree limbs or forks will damage it. So this is why I use string.
Once you get the string thrown into place, remove the sinker and tie on a small rope. Parachute cord works well. I prefer 3/16 or 1/4 inch Dacron.
Tie a small knot. Square knot or my favorite is a sheepshank. A sheepshank knot by definition is used for joining two dissimilar types of rope together. Then I "smooth and taper" the knot with electrical tape, this helps it "slip" through forks and over limbs. I have used a squirt of dish soap on the tape to make it slide even more.
Then stretch out the new rope in a straight line,so it does not tangle.
Then back to the fishing pole and slowly start reeling it in....if it gets snagged, give the rod a flip or let a few inches of line fall back, then reel again....
Last thing on rope...Cotton fiber/ OK (good for a few years)....
NYLON or any "Poly" fiber/ NEVER....Sunlight EATS IT....
Best: Dacron fused with Kevlar fibers (lasts forever/very strong)
I've had one piece of 5/16th's up for over 10 years.
OK Bob! Get busy.
All the Best
Gary
I use a cheap large Salt Water type spinning reel(Catfish reel Large spool) filled with couple hundred feet of 90 lb. string. Large bell sinker or torpedo sinker on the end.(couple ounces or bigger)....Use string, much more flexible than fishing line. Mono-filament line has one issue IMO once it is nicked, even slightly it will fail. Thus pulling it over tree limbs or forks will damage it. So this is why I use string.
Once you get the string thrown into place, remove the sinker and tie on a small rope. Parachute cord works well. I prefer 3/16 or 1/4 inch Dacron.
Tie a small knot. Square knot or my favorite is a sheepshank. A sheepshank knot by definition is used for joining two dissimilar types of rope together. Then I "smooth and taper" the knot with electrical tape, this helps it "slip" through forks and over limbs. I have used a squirt of dish soap on the tape to make it slide even more.
Then stretch out the new rope in a straight line,so it does not tangle.
Then back to the fishing pole and slowly start reeling it in....if it gets snagged, give the rod a flip or let a few inches of line fall back, then reel again....
Last thing on rope...Cotton fiber/ OK (good for a few years)....
NYLON or any "Poly" fiber/ NEVER....Sunlight EATS IT....
Best: Dacron fused with Kevlar fibers (lasts forever/very strong)
I've had one piece of 5/16th's up for over 10 years.
OK Bob! Get busy.
All the Best
Gary
in....
Last thing on rope...Cotton fiber/ OK (good for a few years)....
NYLON or any "Poly" fiber/ NEVER....Sunlight EATS IT....
Best: Dacron fused with Kevlar fibers (lasts forever/very strong)
I've had one piece of 5/16th's up for over 10 years.
OK Bob! Get busy.
All the Best
Gary
I have to disagree with you on one thing Gary.....that is unless you are part of the 95% of the people that mistakenly call that yellow polypropylene crap nylon. I can't even begin to recall how many people call that poly crap nylon. That stuff deteriorates in the sun and becomes full of little splinters. REAL nylon rope is usually white and silky soft and smooth and almost slippery feeling. I have used in it sunlight for years and except for a slight hardening from being wet/dry so many times it has never deteriorated a bit. One piece was on my parents clothesline elevator for over a dozen years and was still fine. I use it as my main tower rigging ropes and all my hoisting slings etc. are all made from NYLON rope. Come to think of it the white rope in the picture I posted above is nylon and had been up for years as of that pix.
I've got a 1000 ft spool of REAL mil-spec 550 paracord for the main support line that will run thru a screw eye in the top of the 4" PVC collector and for haul ropes, and I'm using 50 pound test UV protected mono to keep the radials streched out. That should do the trick...
Well CK, you may be right, However are you sure what your using is 100% Nylon. Some of the rope your describing can be fused with rayon or Dacron fibers to keep it flexible.
I have also seen nylon blended with Neoprene, which keeps it very flexible even in extreme temperatures.
Pure Nylon unless extruded into hairlike size is inherently stiff, correct?
I don't claim to be a chemist but like you years of climbing towers and pulling miles or hundreds of miles of cable I know what works.
I hope I have over time not misunderstood, seems to happen to me lately more time than I like.
My reference to "Poly"...Polyester....Polypropylene etc... is a petroleum based product, as are many synthetic fibers, and yes some are not UV compatible.
I respect your knowledge and experience and if I made a mistake with the Nylon statement,
I stand corrected.
Guess I should check labels a little more closely, chemistry was one of those subjects I should have tried harder to get better than a "C"
All the Best
Gary
I have also seen nylon blended with Neoprene, which keeps it very flexible even in extreme temperatures.
Pure Nylon unless extruded into hairlike size is inherently stiff, correct?
I don't claim to be a chemist but like you years of climbing towers and pulling miles or hundreds of miles of cable I know what works.
I hope I have over time not misunderstood, seems to happen to me lately more time than I like.
My reference to "Poly"...Polyester....Polypropylene etc... is a petroleum based product, as are many synthetic fibers, and yes some are not UV compatible.
I respect your knowledge and experience and if I made a mistake with the Nylon statement,
I stand corrected.
Guess I should check labels a little more closely, chemistry was one of those subjects I should have tried harder to get better than a "C"
All the Best
Gary
An interesting article on rope types, specifically written with use in amature radio in mind, by a chemical engineer who is also a Ham.:
http://www.mapability.com/ei8ic/contest/rope.php
http://www.mapability.com/ei8ic/contest/rope.php
Well Gary the nylon rope I use is silky soft and has thousands of tiny little hair sized strands. When the end of a 1/2 inch piece is cut the cut end feels like a super soft brush. It has a fair bit of stretch to it, more-so than polyester or polypropylene rope.
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