need ideas to make my wire antenna more durable

[KW4DE]

I use parachute cord over the limbs of trees (which stretches in the breeze) and then I suspend/attach my wire antenna to the cord with black cable ties every 10 ft or so.  This relieves the dead weight on the wire itself.  I do not use counter weights/pulleys etc at the ends.  By leaving enough excess parachute line at the ends I can bring the antenna up and and let it down if I want to try something else or if I need to replace a piece of cord due to wear, tear, stress over the limbs.   I have had one 250 ft span up for over 2 yrs without breaking or replacement. BTW the parachute line is  cheap online if you get 1000 ft or so.

[KJ4OLL]

I was wondering about a rope material that had some "give" to it, parachute cord sounds good, like the Kernmantle ropes we used when rock-climbing.
Wonder if there is a version that is UV resistant, my QTH environment (Sun, heat, humidity, bugs, gnawing critters, etc)
obliterates most everything.
I have had to make all labels that are outside from Lead sheet, hand-stamping in the letters & numbers.
73
Frank
KJ4OLL

[WBear2GCR]

You can model the basic antenna in the free version of EZ-NECK (or whatever that is called). But in reality it will make almost no discernible difference to move it those few degrees. Might even help to get it away from the trees a bit...

In practice figuring the resonant freq on the ground is only an approximation, unless you get very lucky. The actual ant in the air needs to be checked and trimmed in the air (yep, pull it up, test, drop it down, rinse & repeat).

                        _-_-

[WBear2GCR]

Dacron is usually best.

Stretchy is not so good, it gives too much for a heavy wire ant.

Suggest using one of the various methods for tensioning; springs, counterweights.

[flintstone mop]

A shotgun blast that worked!!!
I upgraded my "True Ladder Line"  flat top dipole cuz of a strange problem with a 2:1 SWR over a 20kc slice of 160M. I could not tune it out. Everywhere else almost 1.2:1 match. I could not afford to go #10 but did move up to #12awg stranded from #16 on the original antenna. The price and weight increase to #10awg was not in the plans. #10awg is going to be a lot heavier to hoist and support than #12.
The new dipole is almost perfect 1:1 everywhere. That strange little slice in 160M is gone.
When I was checking the line length, I was running my hand along the old piece of wire and the new wire and I could feel a lot of rough spots on the old wire. I looked closer and they were slits in the insulation. It was cold and getting colder and cloudy. I wanted to end the project from wandering around the property for 2 1/2 hrs Saturday afternoon.
There's a possibility that the slits was allowing water to enter into the copper and there was probably going to be another major failure of the antenna in the future.
My hat's off to the guys who put serious effort into their wire antenna with good supports, should be three supports, and use that copper clad stuff. Not easy to work with and could put your eye out.
The "TrueLadderLine" antenna is a neat idea of using one continuous piece of wire that goes from ladder line and then becomes antenna line at the "T". They wrap a couple of turns of ladder line through some extra holes to secure it as it becomes  the antenna. They use #16 and it is definitely on the weak side.
Gots nice fresh copper up there now and that nice match. I hope there's an improvement in the radiated signal.
This was a very nice thread and great replies.
Fred

[KL7OF]

I once put up an 80 meter full wave square loop vertically  between two pine trees......It was an experiment and I used weed wacker line to suspend the wire between the trees...because I had a big roll of the stuff...It is basically 120 lb test monofilament nylon line and it must be UV resistant because that antenna stayed up for 3 years before I took it down and the line was still strong and flexible ....I have been using weed wacker line ever since.  It stretches and flexes when the trees move, it is resistant to the sun, and it comes in many colors...I like black or clear....Give it a try....

[KJ4OLL]

Hi,
With a few days remaining until the "antenna building" high-reach machine is to be delivered, I have been working on getting the antenna ready.

Found a mostly complete 500ft. roll of #10 stranded, left over from some electrical project.
Cut a piece of that green fiberglass "stack together" military antenna mast material, so as to make a feed point mount at the top of the mast.




I was going to use the original small gauge feed line, as it came from Trueladderline.
But there is plenty of #10 remaining, so I'll make the feed line out of that, rather than what is shown in the photo.

Not sure about the number of turns of #10 at the feed point.
I can see how many K5JYB (SK) used, but should I duplicate the same number of turns w/ #10?



73
Frank
KJ4OLL

[Steve - K4HX]

Not sure about the number of turns of #10 at the feed point.

What is the purpose of these turns?

[N4zed]

Boy if I had a "high Reach" machine coming I would put at least 3 eye hooks in each tree as high as I could get them and put a pulley on each with a line through each one of them...Just think of the possibilities !! 

Oh the redundancies !   

If I only had some flat land to park one of those machines..... 

[KJ4OLL]

Steve,
I don't know, that is how it was delivered from Charlie @ Trueladderline.
As he is no longer with us, I can only guess:

- Possibly the inductance would have some damping effect on lightning-induced energy?

- Adding inductance so as to allow for a shorter cable?
(It's 120' long for each run, so what  benefit???)

- It's just strain relief for the tiny 16AWG stranded?

I looked in an old ARRL antenna book, and in Bill Orr's antenna book, can't find anything.
Frank

[Steve - K4HX]

There is no good reason for inductance at the feed point. If it's more than 2-3 turns, get rid of it. A few turns may be there for some mechanical strength reason.

If I had a high-reach machine, I'd use it to affix masts in the trees. Then my antenna wires would be above the tops of the trees - no loss and no broken wires from abrasion.

Good luck with the antenna project. It's supposed to be 68 degrees here on Wednesday. I may be doing some antenna work too!

[flintstone mop]

There is no good reason for inductance at the feed point. If it's more than 2-3 turns, get rid of it. A few turns may be there for some mechanical strength reason.

If I had a high-reach machine, I'd use to to affix masts in the trees. Then my antenna wires would be above the tops of the trees - no loss and no broken wires from abrasion.

Good luck with the antenna project. It's supposed to be 68 degrees here on Wednesday. I may be doing some antenna work too!

I'm on the thought that the 2-3 turns is for mechanical strength for the transition of the Ladder Line becoming the antenna. The possible inductance doesn't seem to be altering the performance of my True Ladder Line antenna.

Fred

[KJ4OLL]

Hi,
Made some progress today!
Two 90' runs of #10 AWG for the ladder line.
I have never made ladder line before, but fortunately, had the special tool
already at hand. (big silver thing w/ the wire draped over it 


73
Frank
KJ4OLL

[flintstone mop]

It looks good Frank
Fred

[N4zed]

If I had a high-reach machine, I'd use it to affix masts in the trees.

Really good idea !

I'll put that in the keep file !

Ken
N4zed

[KL7OF]

You can't use wire with blue insulation....for ladder line...other than that, it looks very good

[KD6VXI]

Man.   I didn't think of the tall silver thing.

Instead,  I used a custom made,  imported from Mexico,  58,000 dollar wire stretcher when I made my 100 foot section of ladder line.

Plebes called it my 1 ton Dodge Dually.   I called it my wire stretcher / puller.

Ladder looks SO much cheaper!

--Shane
KD6VXI

[KB2WIG]

Well, the feed line is spoused to be balanced, but its not. Specially caus only one side is blue.


klc

[flintstone mop]

The colors are to identify the phasing of the RF.

Fred