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Thread: 600 ohm open wire (ladderline) construction

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  1. #31
    Join Date
    Jan 2000
    Location
    Commerce MI (Detroit area)
    Posts
    8,231

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    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??
    73.....JD, FISTS #3853,cc 455,SKCC # 1395,tribune #12,
    Official US Taxpayer

  2. #32
    Join Date
    Nov 2002
    Location
    Park Hills,MO
    Posts
    3,450

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    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.

  3. #33
    Join Date
    Oct 2003
    Location
    Middle Georgia USA
    Posts
    7,722

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    Quote Originally Posted by [b
    Quote[/b] (w6fo @ Oct. 05 2006,11:57)]
    Quote Originally Posted by [b
    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.

    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

  4. #34

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    very simple, about 30 dollars total

  5. #35
    Join Date
    Jul 2001
    Posts
    21,474

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    Quote Originally Posted by [b
    Quote[/b] (w8znx @ Oct. 05 2006,12:39)]
    Quote Originally Posted by [b
    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.
    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

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