Best way to use 200 feet of wire

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KF7AYS, Mar 29, 2010.

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  1. KE5FRF

    KE5FRF Ham Member QRZ Page


    7AYS,

    I do not think you quite understand what these fine folks are telling you, and perhaps you are being a bit narrow in your vision due to some common misconceptions.

    The last post you made said that you aren't going to use a tuned antenna. By that, and your earlier comments, it sounds like you mean a resonant dipole.

    OK, well don't!!! Thats fine. You are correct that a resonant, coax fed dipole only really works well on the band it is cut for, and if you are lucky it will perform well on two or three other bands.

    But let me tell you from experience...You will probably be unhappy with an end fed random wire.

    But what all of these people have been telling you is that you aren't out of other options that might work very well for you!

    Did you investigate Cecil/W5DXP's link to the ladder line fed doublet with his ladder line and switch tuning system? He is using pre-cut pieces of ladder line as matching stubs configured with switches to modify the length of his feedline. He's using his feedline to tune the antenna!

    Now, this isn't the easiest way to do it and I'm sure Cecil himself would tell you a commercial tuner or transmatch (with a balun) is an effective system too. But Cecil's antenna design proves one thing, a very efficient and effective multiband antenna CAN be built from a single "dipole".

    But this antenna NO LONGER is called a "dipole" whenever you feed it with BALANCED FEEDLINE instead of coax and use a matching system like Cecil's or a commercial tuner. Instead, it becomes a "DOUBLET".

    I've seen several folks suggest the doublet antenna to you, but I keep hearing you bypass that option. I think you may have a misconception about tuning a dipole because of your experience with coax. Well, THE COAX IS THE REASON YOUR ANTENNA BEHAVED POORLY. I've tuned coax fed dipoles myself, and rarely am I happy on any band other than the resonant band of the antenna's design!!!

    But any kind of balanced feedline (open wire with spreaders, twin lead, ladder line, even lamp cord or twisted pair has been used!!!) ...it will work better than coax when used multiband with a tuner!!!

    So what people are telling you, you have 200 feet of wire. Take 100 feet (or slightly more or less, there ARE optimal lengths) and make the two elements for a doublet. More is better. I think 130 feet (two elements 65 feet long each) is supposed to be optimal. I think I've also seen 121 feet or 88 feet used. OK, so that leaves you with at least 70 feet of extra wire. I don't know where your antenna support or shack are located, but you can use popsicle sticks evenly spaced to spread the wires and make your own "window line". If your antenna support is close to the shack, you might be able to get the antenna as high as 30 feet in the air with this method.

    But if you want to save time and effort, YOU CAN ALSO PURCHASE PRE-MADE LADDER LINE from a company like DX-engineering or "The Wireman". 450 ohm tends to be recommended but 300 ohm will work too. EVEN CHEAP RADIOSHACK TV TWIN LEAD WILL WORK and it is readily available.

    What everyone here is telling you is that this will be a VERY efficient antenna, you will make TONS of contacts on all bands (specifically, from experience, 40, 20, 30, 15, and 80 meters if you get it high enough, will be great bands for you. You might have trouble tuning one or two of the WARC bands, but even THOSE bands will be usable. With a very good tuner, you can even use this antenna on 6 and 2 meters with moderate success!!!!

    Nobody is trying to convince you to build a dipole. We are trying to convince you to not waste time with end fed and build a DOUBLET. We understand that some times, in some cases, an end fed is literally the only choice. I used one myself as recently as 3 months ago. But I knew from experience that there were WAY better antenna choices available to me, but I was trying to be stealthy. What I wound up with was RF in the shack and a lot of grief trying to mitigate it.
     
  2. AF6LJ

    AF6LJ Ham Member QRZ Page

    KE5FRF;
    Well put; as has been pointed out a random wire is going to be a poor performer and problematic regarding RFI.
     
  3. KE5FRF

    KE5FRF Ham Member QRZ Page

    Oh, one more comment.

    The suggestion to use a loop is another really good one. If you can put 200 feet of end fed wire into the trees, you can just as easily put up a loop. 200 feet of wire in a loop (triangular shaped, square, circular, even slightly rectangular) will tune up 10-40 meters VERY well and will even work reasonably well on 80 meters. In a pinch, it will probably tune 160 meters and work out to 500 miles or so. I currently have a roughly triangular loop (slighly acute) that slants from about 15 feet high at the feedpoint to about 25 feet at one tree support (corner) to the other corner which is 45 feet up in a tree and back to the 25 foot feedpoint. The wire length is random, but I estimate it to be about 250 feet of wire. And it works all bands 10-80 meters very well (except I have to reduce power on 12 meters because I get a little RFI otherwise). I've made contacts on 160 meters with it. I use a remote tuner, but a local tuner (in your shack) will work as well if you are feeding it from that point with balanced feedline!

    This is the key, my friend. If you plan on using a tuner to work a single antenna multiband, the key is to get away from coax and use balanced feed. It is that simple. Your experience with coax has left an incomplete picture for you and you can't appreciate what we are telling you without experience.

    Trust me, I change antennas like I change underwear (every 6 months to a year) :eek: just for the fun of it. I've used end fed, dipoles, doublets, inverted vees, fan dipoles, folded dipoles, loops, verticals with ground radials, and beams, many antennas coax fed and many balance fed. For all-band purposes, nothing beats a doublet or random loop with a tuner and balanced feedline. There are TONS of documents on the internet and in books that sing the praises of this type antenna. I suggest you read further before commiting to an antenna that you won't be happy with.
     
  4. KE5FRF

    KE5FRF Ham Member QRZ Page

    Thanks Sue.

    I agree...except for the "performer" part (to an extent). I WILL admit that the end fed wire I was using worked reasonably well with a counterpoise as far as making contacts goes. I worked the ARRL DX (CW) contest a couple of months ago with it, and made some pretty darn good contacts, even TX4T on 15 meters. I also worked TX4T on 80 meters about a week before the contest, and made boatloads of DX contacts on 40 meters and some on 20while I had the antenna up. My biggest issue was RFI on 30, 15, 12, and a little on 20 meters.
    Particularly 30 meters, I had complaints about my CW sounding horribly choppy. A field strength evaluation confirmed I had WAY too much RFI on 30 and 12 meters in the shack and it was getting into my equipment.

    In all honesty, on 80 meters and 160 meters, I think the end fed wire worked BETTER than my current loop. Of course it was 120 feet of wire with 60 feet of balanced line (in a zepp configuration). I just couldn't handle the RFI. I even had some bad reports on 40 meters now and then and had to cut power back.

    It just wasn't worth it to go that route. I still say that the best antenna I ever used was a 120 foot doublet with 300 ohm ladder line about 45 feet up in a slight inverted vee shape. But I had to relocate my shack, and my wife doesn't like the ladder line's profile in the back yard. To the original poster, this is the only negative about ladder line. It isn't very stealthy. However, the radio shack twin lead I mentioned is fairly streamline and isn't as noticeable if stealth is an issue. Only bad think about it, its a little more lossy and I'm not sure it will last as long as ladder line.
     
  5. KF7AYS

    KF7AYS Ham Member QRZ Page

    At issue here is not whether or not those other options are good or not. Personally, I would rather run a dipole, or a vertical, or something else fed with Coax, ladderline, or whatever.

    The issue here is that I have a window screen that I can pass very small wire through to get outside of my apartment. So, Ladderline, coax, etc is not an option. I can, however, potentially set up a loop though as the wire going in and out of the apartment will be fine enough to get through the screen.

    So, I will give that a try.

    Thanks all,
     
  6. KJ4RZZ

    KJ4RZZ Ham Member QRZ Page

    Why not remove the screen or replace it with a custom screen of the same size and save the original one for when you move?
     
  7. KE5FRF

    KE5FRF Ham Member QRZ Page

    If getting the wire through the screen is the problem, I have a suggestion.

    By "going through the screen", do you mean LITERALLY going through the screen mesh itself, or do you mean between the screen frame and the window frame?

    Either way, may suggestion. If one piece of your fine wire will get through, then surely two pieces of the same wire will get through. Cut two equal pieces of the wire about 6 inches long, so that when you push them through the screen, 3 inches hangs out the window and three inches hangs inside of your apartment. You should space the two pieces of wire two or three inches apart. Before pushing them through the screen, strip both ends of both pieces of wire about an inch back to expose the copper conductor. Secure both pieces of wire in place on the screen in whatever manner is most handy. Strong tie wraps snugged up against the wire and pushed up to the screen material on both sides would be a good method. If you really wanted to do it right, you might even take a thin, light piece of wood, about 3x5 inches rectangular (or 4x4 square whatever you have) and drill 4 holes for small screws and washers, as well as two holes for the wire to pass through...this might help "reinforce" the spot where the wire passes through the screen to keep the wind from ripping the wire out. Heck, even a few popsicle sticks held in place by screws and washers would do the trick!!

    So what you have now is two pieces of wire passed through the screen without damaging it (other than maybe stretching the mesh a little in spots)

    Now, you can take some good ladderline (homebrew, storebought) and run it to your tuner. You really should have a balun in the tuner, but often an external current balun works even better. In this case, you would use a short coax jumper coming out the back of your tuner to a 1:1 or 4:1 current balun. Voltage baluns work too if you have one available but they are usually not as robust and less efficient.

    So, solder the ladder line to your short wire stub at the window. you might slip a piece of heat shrink over the wire before soldering, and then once soldered slide the shrink over the joint and use a heat gun to shrink it.

    Do the same thing, if feasable, outside the window. Can the screen be removed for this part? Is this window accessable outside from the first floor or with a ladder? Of course, be careful soldering from a ladder, but either way, perform the same operation with the wire on the other side of the screen and some more ladder line....(enough to traverse the distance and height to where your antenna feedpoint needs to hang). Some people twist ladder line every so many feet to reduce common mode currents and prevent coupling (same reason twisted pair is twisted).

    Hang your antenna, attach to ladderline at feedpoint, and start DXing!!!

    If you aren't good at soldering, and want a more temporary installation, good quality, strong, wire-nut (twist on connectors) will work to connect the 4 connections you need to make. If you really wanted to be fancy and make it more professional, you could put terminal screws on the wood board and use through-hole crimp on terminal connectors and nuts and washers to hold the wire in place. You could even mirror this on both sides with two little wooden boards. And of course, there are ceramic wall connectors specially designed for ladder line that work well too.

    The one thing you need to be careful of is having ANY metal or exposed contact points in the wiring touching the screen, particularly if the mesh is made of metallic material as well. For instance, if your pass-thru wire was not insulated you would potentially cause a dead short in your feedline.

    Ok, so I hope some nugget of help lies in my posting. We're trying to help you put together an antenna system that you'll be satisfied with and not struggling to make work for weeks and months. The problem is, if you don't hear your own signal, often you just don't realize how much RFI is hashing it up. Without a large chunk of metal or conductor in proximity to your ladder line to cause coupling problems, this should be a good antenna for you.
     
  8. KF7AYS

    KF7AYS Ham Member QRZ Page

    OK. I hooked up 100 feet of wire to the Ant-3 pole on my at-230 today. It tuned up just fine but I could not hear anything.

    So, I set up the other 100 feet of wire on the grounding lugs on both my ts-830s and at230. Much better ears, but still not good.

    I did, however, make a contact in Yreka, Ca from Olympia, Wa. I think that is about 350-400 miles and could hear him well enough. He said that I was coming through really well.

    More experimentation is needed at this point.
     
  9. K7SWS

    K7SWS Ham Member QRZ Page

    Not that I'm any expert but I have used an at-230 tuner with a long wire, 200+ ft of aluminum electric fence wire with a counter-pose and had good results. All the counter-pose wire I used was junk romex that I laid on the ground.I could tune 40 cw and 10 but 15 for cw wasn't very good(about 3to1) . I'm just a tech but made 20+ 10 meter contacts with my junk antenna.
     
  10. KJ4LZM

    KJ4LZM Ham Member QRZ Page

    All,
    I have a little different, but similar situation I need help on. I have around an acre of land with many, many trees, some as high as 80 ft on my lot. My challenge is distance to the shack. It's on a second floor room above the garage. I have had 2 runs of coax from the outside front wall of the garage and then up to the operating position. I have had an 80 m dipole up around 35 feet. I dropped a twin lead down to an "ugly" balun to coax and ran it abut 50 feet or so to the junction box and connected it to the coax that then ran to the radio on the second floor. I would like to move the antenna to the rear of my property, but that would add around 100-150 feet to the shack.

    Questions/comments:
    1) Would ladder line be better to run to the shack than coax?
    2) I use the radio's (756 Pro III) internal tuner, so I need to run coax to it
    3) Should I run ladder line to the junction box outside the shack and then use a 1:1 current balun there?
    4) Am I crazy to want to locate an antenna so far from the shack?!

    Any help would be appreciated.

    Joe
     
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