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VA3GRV
10-05-2006, 01:16 AM
Hi Folks,

I'm looking for plans to build my own ladderline, can anyone steer me in the right direction? Can't seem to find any plans online. Also how to run it into my shack.

Thankyou
73 Vince

AG3Y
10-05-2006, 01:22 AM
Virtually any ARRL Antenna Handbook that I can remember ever seeing, has instructions for building open wire feeder. There are charts for wire gauge, spacing, and hints on choosing insulator material, ranging from wax-soaked dowel rods to plastic clothes-hanger rods.

You shouldn't have too much trouble finding the book, which is available at almost any hamfest. Or do what I just did recently, and pick up a copy at a used book store in your area.

Good luck ! 73, Jim

VA3GRV
10-05-2006, 02:05 AM
Thankyou Jim, Guess I'm being lazy hihi, Thought for sure I would have found something on the web. Maybe I'll have to order a book.

W5DXP
10-05-2006, 02:18 AM
Quote[/b] (VA3GRV @ Oct. 04 2006,20:05)]Maybe I'll have to order a book.
It's certainly not rocket science. W7FG uses normal #16 insulated wire and makes the spacers out of half inch irrigation tubing available at Home Depot or Lowes. Spacers are about three inches long with notches in each end for the wires. Piece of cake.

AG3Y
10-05-2006, 02:32 AM
I've seen ladder line with the spacers threaded on the wire, but the easier way to do it is to make the knotches as Cecil suggests, and then use small pieces of bus wire to fasten the line in the notches. The bus wire has negligible effect on the characteristics of the feedline.

Remember that it is really not all that important to match the antenna impedance to the feedline impedance when working with this setup, unless you are actually trying to transform one impedance to another using the line as a quarter wave matching device. Most instances I know of, that is not the case. One of the very first installations I ever saw used open wire feedline spaced about 4 inches apart, and the setup worked like gangbusters! I seriously doubt that the fellow actually had any idea of what the feeline impedance actually was !

I'm using some commercial ladder line here, but the only "design" consideration that I used was to make sure I had enough line to go from the feedpoint of my antenna to the balun just outside the wall that I feed a short piece of coax through. Real scientific approach for this "Extra-Class Snob", but I certainly make as many contacts as I care to with the setup, so as the old saying goes, "if it works, don't knock it! "

http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif

VA3GRV
10-05-2006, 02:46 AM
Ok Thanks Guys....I thought there was a formula for the spacing.I thought I would try it, my current inverted V works good but I thought maybe I could improve by running some 600 ohm right to the tuner that has posts for open wire, rather than using the 31 ft. of 300ohm ladderline with a coax balun then to the tuner. The ant. seems pretty good I had a qso with Trinidad on 20m last night! Thought that was Cool!

AG3Y
10-05-2006, 03:27 AM
Oh, there is a formula for the spacing, but that, and the wire gauge all work together to determine the actual impedance. As I said, there are charts in the ARRL antenna handbook, but the actual impedance is a fairly minor consideration as the losses due to an impedance mismatch are very minor for open wire feedline, as compared to the same type of losses for coax cable. The stuff is wonderful to work with. The only thing you really need to watch out for is to keep it a reasonable distance away from other metal. For instance, don't tape the stuff to your tower, or run it along a downspout or the gutters! Stay away from aluminum siding, and you should be OK . http://www.qrz.com/iB_html/non-cgi/emoticons/wink.gif

73, Jim

VK4XJB
10-05-2006, 03:36 AM
Quote[/b] (VA3GRV @ Oct. 05 2006,12:46)]I thought there was a formula for the spacing.
Z = 276 * log(2 * S / d)

S is the centre to centre spacing of the wires
d is the diameter of the wire

S and d are in the same units.

N9FE
10-05-2006, 03:44 AM
wa3grv, if you can run your open wire right to the tuner that's the best, a balun right outside the house like ag3y did work's well to, you can also run two piece's of 'i beleve" 75 ohm coax to get you out of the house, as long as your open wire is not laying on metal, you'll be ok, i kept mine a foot off the tower with pvc standoff's, i also run right to the back of the tuner, and use the balun in the tuner, you might have to add or subtract some feedline length to work all band's,, welcome to the world of open wire, this next summer a couple of us are going to experiment with open wire for uhf and vhf, i went from s9 to 20 over to everyone, even the long hauls, mark

WD8PTB
10-05-2006, 11:35 AM
Yes there is a formula but in most cases low loss is what is desired so the actual impedence is not critical. I have seen various spacing ,ussualy with #12 or 14 electrical wire, ussualy hooked up to a balanced output of a tuner. Don WD8PTB

N4AUD
10-05-2006, 01:58 PM
I've used small diameter PVC pipe for spacers, people have cut up plastic coat hangers as spacers, and currently I am using "mini popsicle sticks" available at craft stores as spacers. I've used regular 12awg insulated stranded wire as a conductor and am currently I'm using some "lamp cord" that I pulled apart as my conductor. I don't expect it to hold up in the weather but for now it is working. I use "Goop" industrial adhesive to fasten the spacers once I get them in place.

You'll have to stretch out both conductors and apply the same amount of tension to both when you are placing your spacers. If you have one wire more taut than the other, your spacers will not be straight. I just drilled holes in my popsicle sticks with my drill press and slid them on, but you can obviously cut a slit and slide your spacers on. If you are going to use PVC, plastic coathangers or some other material for your spacers and you don't have a bandsaw, it can get really tedious cutting the spacers one by one with a hacksaw. That's what led me to use the popsicle sticks and so far, to my amazement, they've held up in the weather.

AG3Y
10-05-2006, 03:35 PM
Did you soak the popsickle sticks in wax? Or perhaps shellack them ? They should last for years if you did either of those things.
http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

K7KBN
10-05-2006, 03:47 PM
Quote[/b] ]I seriously doubt that the fellow actually had any idea of what the feeline impedance actually was !


Depends on how the cat felt about what you were trying to do... #http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif

N1ESE
10-05-2006, 03:48 PM
As I am starting to build my open wire feeders, I am wondering how close together feeders need to be and whether distance between wires in the section between spreaders can vary at all? With wire like this, I don't really think it's possible for it to be a constant 4", or whatever, distance throughout the entire run. Will small variances negatively impact performance of the feedline?

I'm using 14 ga. stranded THN as it is what I have under the bench. Two continuous runs make up the feedline and antenna elements. Using 1/2" CPVC for the center and feeder spacers.

K7KBN
10-05-2006, 03:57 PM
You Could Do Much Worse Than Refer To This (http://www.cebik.com/trans/par.html)

Google is, as I've said many times, your friend.

I've made homebrew parallel line using 3/8" diameter plastic rod cut into ~4" lengths. I used a "hot knife" to cut grooves the proper width for the wire I was using, and when the wire was in position I'd take a soldering iron and melt the plastic over it, making a pretty secure condition. At least none of the wires ever popped out.

N1ESE
10-05-2006, 04:06 PM
Here's the start of my open wire antenna, I am probably doing something wrong but if it works I'll be happy.

http://img149.imageshack.us/img149/6581/doubletge2.jpg

W8ZNX
10-05-2006, 04:39 PM
Quote[/b] (AG3Y @ Oct. 05 2006,08:35)]Did you soak the popsickle sticks in wax? #Or perhaps shellack them ? #They should last for years if you did either of those things.
http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif
have used Thompsons Water Seal
soak the wood for a week or so

with weight on top
to keep the wood
under the water seal
most likley other brands
would work just as well

works better than
wax, shellac, or varnish

man shellac !
nobody uses shellac any more
dam stuff is a pain to work with
and it's more expensive
than good spar varnish

Mac

K7KBN
10-05-2006, 05:03 PM
You want to be sure the Ty-RapsŪ, Zip-TiesŪ or whatever you want to call them are UV resistant. Generally the UVR ones are black. Exposed to sunlight, the non-UVR versions will break in just a few months.

N1ESE
10-05-2006, 05:12 PM
Quote[/b] (k7kbn @ Oct. 05 2006,12:03)]You want to be sure the Ty-RapsŪ, Zip-TiesŪ or whatever you want to call them are UV resistant. Generally the UVR ones are black. Exposed to sunlight, the non-UVR versions will break in just a few months.
Yeah, these are probably not UV resistant but they are all I have at the moment. I need to make do with what I have according to the YL. *grin*

This will hopefully only be a temporary antenna. I will pull it down in a few months and see how they are holding up and replace if necessary.

K3STX
10-05-2006, 05:34 PM
OK, I'll play the fool and say "I don't get it." If you want to do it for fun, I can see it, but are you somehow doing this because you think it will be superior to the dirt cheap window line that is commercially available?

To put on wrap-ties that will disintegrate in a year and then replace the whole thing with 200 more wrap-ties that are UV resistant sounds like a masochist to me.

paul

N1ESE
10-05-2006, 06:57 PM
Quote[/b] (K3STX @ Oct. 05 2006,12:34)]OK, I'll play the fool and say "I don't get it." If you want to do it for fun, I can see it, but are you somehow doing this because you think it will be superior to the dirt cheap window line that is commercially available?
No, because all the die hard doublet builders say the commercial window line is inferior to 600-ohm home brew.

I'm damned if I do, damned if I don't, on these forums.

If I use commercial 450-ohm, I'll get 10 post cursing the project for not doing it right by homebrewing.

If I homebrew it, I'll be called a masochist and yelled at for not taking the simple way out and buying 450-ohm window line.

http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif

N3BIF
10-05-2006, 07:26 PM
I have wondered the same thing, outside of the "recreational" value of this labor intensive project , do the results warrant the effort ? #As yet I have not been convinced that it is. I will continue to use 300 ohm parallel line till shown otherwise, sorry...

K3STX
10-05-2006, 07:29 PM
I use window line, and I am a real dummy, I don't evven use the "flexible" stranded wire stuff (the solid wire stuff is cheaper). Has been up for more than 2 years, no problems at all.

Other than the 450 ohm line having a real impedence of only 400 ohms, I can't see any problems. Takes tons of power, and they make nice center insulators/dipole connectors for them.

paul

p.s. don't worry so much about what people think of you.

N1ESE
10-05-2006, 07:29 PM
Here's a nice homebrew ladder line site:

http://ka8vit.com/hbll/

N1ESE
10-05-2006, 07:42 PM
The main reason I am doing homebrew myself is the fact that I'm on a super tight fixed income at the moment and can't spend the $28.00 + $8 shipping for 200 feet to reach the shack.

I have three rolls of 14 ga. THHN under the bench and need to get a multi-band wire in the air so homebrew makes sense even though it's more work.

All I have in the air at the moment is a 20M resonant half-wave dipole.

AL7N
10-05-2006, 09:02 PM
Go ahead and home brew your open wire line.....it ain't critical what the spacing is....I like to use three or four inches, but in the real world, it doesn't matter much what the actual "characteristic impedance" is since the line is normally operating at a mismatch anyhow in the case of a feedline to a dipole antenna. Only requirement is that it be fairly constant over the length of the run.
Spacers can be made of anything that insulates and is stiff enough to hold the wire of choice apart . #Wire can be insulated or bare, solid or stranded, anything that is stout enough to hold itself together in the air for the required span lengths to be run. and it should be supported for long runs and properly "deadended" with insulators at the ends.

When building your feeline, it will be helpful to find a place to work where you can stretch two lengths of wire out close to the spacing desired apart for the required distance, and then apply the spacers between them while pulled taught. #This makes it easier to get the spacers straight and consistent in distance between them. #Tiewires or tywraps (UV resistant), glue, #or something similar needs to be put on the ends of the spacers to hold the line wires to them. #

Thats all there is to it....make the feedline long enough to reach from the center insulator of #your antenna to wherever the shack is located, #use a good balanced tuner circuit, and go for it.

VK4XJB
10-05-2006, 09:21 PM
Quote[/b] (w6fo @ Oct. 06 2006,04:57)]
Quote[/b] (K3STX @ Oct. 05 2006,12:34)]OK, I'll play the fool and say "I don't get it." If you want to do it for fun, I can see it, but are you somehow doing this because you think it will be superior to the dirt cheap window line that is commercially available?
No, because all the die hard doublet builders say the commercial window line is inferior to 600-ohm home brew.

I'm damned if I do, damned if I don't, on these forums.

If I use commercial 450-ohm, I'll get 10 post cursing the project for not doing it right by homebrewing.

If I homebrew it, I'll be called a masochist and yelled at for not taking the simple way out and buying 450-ohm window line.

http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif
How about a - go for it and make your own ladder line? http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif

Mine is 4 inch spacing with 2mm diameter wire and the spacers are 2 feet apart. I tried one end of the wires to the back veranda and the other end to a post so the wires were stretched out and off the ground. Found that easier to work with then having the wires loose.

One thing I like about the homebrew stuff is it does not seem to be affected by rain. I know 2 people that use 300 ohm ribbon that have issues when it rains. Performance drops and the tuner settings change. Have read the same can happen with window line. With the home made stuff I notice no difference wet or dry.

N9FE
10-05-2006, 09:39 PM
AL7N exactly, go ahead and build your own, and learn what you learn along the way, open wire line is so simple, some folk's just cannot get there head around the idea, i'll say it again, the best thing i ever did was throw my coax fed dipole in the garbage, 4 inch spacers, no problem's what so ever, and the best thing is the 100 watt's that comes out the radio, radiates out the dipole, NO loss, no velocity factor, nothing, simple is good,, N9FE

N4AUD
10-05-2006, 10:05 PM
Quote[/b] (N9FE @ Oct. 05 2006,17:39)]AL7N exactly, go ahead and build your own, and learn what you learn along the way, open wire line is so simple, some folk's just cannot get there head around the idea, i'll say it again, the best thing i ever did was throw my coax fed dipole in the garbage, 4 inch spacers, no problem's what so ever, and the best thing is the 100 watt's that comes out the radio, radiates out the dipole, NO loss, no velocity factor, nothing, simple is good,, N9FE
I don't "do" coax on HF either. I homebrew my own ladder line because I get the materials cheap, and because I like doing it and I think mine is better than the commercial variety. Same reason I handload ammo, homebrew beer, work with wood and all that kind of stuff. Some of us are builders and tinkerers and some ain't.

VA3GRV
10-05-2006, 11:00 PM
WOW Thanks A Million Gents!!! That's Terrific!! Can't Wait to build one ;) http://www.qrz.com/iB_html/non-cgi/emoticons/biggrin.gif http://www.qrz.com/iB_html/non-cgi/emoticons/laugh.gif

K8JD
10-05-2006, 11:32 PM
Looked at the homebrew ladderline & Eyeball calculating looks like higher Z than 600 ohms.
Someone I contacted on the air the other night told me he had a "homebrew dipole" ..Made me wonder if he made his own wire and insulated it with strips of silk torn from his wife's discarded petticoats??? Braided his own shield for the coax??

N0WVA
10-06-2006, 12:15 AM
Ive just been through all this ladder line construction stuff. I spaced #14 at 5" with lightweight water supply line, the stuff they use under the sink. Cuts easy and is light. I drilled a hole in each end, then used zip ties to tie the wire to it. Well, After about 75 foot of messing with it, I siad to heck with it and bought some high power 300 ohm ladder line from the wireman. Its sooo cheap, its really not worth the hassle of making the open wire stuff, unless you are overly concerned about operation in wet weather. Open wire will work fantastic when wet, window line will have quite a bit of loss.

So I used 200 ft of 300 ohm ladder line, then used what I had built of the open wire line to make a nice 5" spaced folded dipole for 40. And man is it broad banded. I would also guess that it is a pretty good match for the feedline, the only weak link in the system would have to be the Dentron super tuner. From what I hear its not truly balanced like a Johnson Matchbox, but at any rate, the whole lashup beats the pants off a coax system.

W8JI
10-06-2006, 12:40 AM
Quote[/b] (w6fo @ Oct. 05 2006,11:57)]
Quote[/b] (K3STX @ Oct. 05 2006,12:34)]OK, I'll play the fool and say "I don't get it." If you want to do it for fun, I can see it, but are you somehow doing this because you think it will be superior to the dirt cheap window line that is commercially available?
No, because all the die hard doublet builders say the commercial window line is inferior to 600-ohm home brew.

I'm damned if I do, damned if I don't, on these forums.

If I use commercial 450-ohm, I'll get 10 post cursing the project for not doing it right by homebrewing.

If I homebrew it, I'll be called a masochist and yelled at for not taking the simple way out and buying 450-ohm window line.

http://www.qrz.com/iB_html/non-cgi/emoticons/wow.gif
Let me toss this into the mix.

The BEST impedance for the line is actually lower than 600 ohms. As a matter of fact if you plan the line length and antenna length correctly the best feedline impedance is down around 300 ohms.

If you don't plan anything then it makes very little difference what you use.

In a world where we assume your tuner handles a very wide range of impedances, any feedline impedance between a few hundred and several hundred ohms would be OK. It doesn't make much sense to plan line impedance when nothing else is planned.

I would not bet your feedline would have much less loss than window line. Really low loss open wire line has very low loss insulators and bare solid conductors that are pretty heavy gauge. You have PVC insulation right around the conductor, right where the electric field is highest.

The real important thing is you are BUILDING the line. That is what matters. That is what is really important!

73 Tom

N9FE
10-06-2006, 12:53 PM
very simple, about 30 dollars total

AG3Y
10-06-2006, 03:03 PM
Quote[/b] (w8znx @ Oct. 05 2006,12:39)]
Quote[/b] (AG3Y @ Oct. 05 2006,08:35)]Did you soak the popsickle sticks in wax? Or perhaps shellack them ? They should last for years if you did either of those things.
http://www.qrz.com/iB_html/non-cgi/emoticons/smile.gif
have used Thompsons Water Seal
soak the wood for a week or so

with weight on top
to keep the wood
under the water seal
most likley other brands
would work just as well

works better than
wax, shellac, or varnish

man shellac !
nobody uses shellac any more
dam stuff is a pain to work with
and it's more expensive
than good spar varnish

Mac
Shellack indeed ! ! ! Whoooh "Senior Moment" ! Sorry, of course I was thinking of more modern clear varnish !

73, Jim