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My antenna system...

Discussion in 'CB Antennas' started by Oatmeal, Mar 16, 2012.

  1. Oatmeal

    Oatmeal Active Member

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    I went back on the mountain last weekend and made the changes...
    This is what everyone around my neck of the woods call this "A Mountain Line"...

    I took the Imax 2000 down from where it was, checked it all out, and moved it about 25ft in which I had to add 25ft of hard line wire to what I had to make this move...moved it back in the location I had set up to put a small beam at...
    So, I moved the antenna back there, I put 24ft of new RFC 400 coax going up to the antenna but the ant is still just 21ft off the ground..
    I wrapped the PL up in weatherized tape, then black electrical tape, then put a big gob of silicone all over this..



    And here at the radio, also went with 24ft of new RFC 400 coax...
    Before I taped it all up I did check the swr and it runs a 1.1 to flat across the bands...so went back out and taped it all up like I did up top..
    Im running about 625ft of hard line wire to the base of the tree the antenna is up against..

    I did a little more checking with the swr...
    First checked it with a 10w dk, swr was still a 1.1 to flat...
    Checked it again with a 30w dk swr stayed the same...
    This swr is from channel 1 up through the 28.000 band.

    It talks great with just running the radio..
    Just thought Id share with you all what Ive done...
    #1
  2. Marconi

    Marconi Supporting Member

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    Oatmeal this is my opinion, and I can't prove the idea, but the following has been my experience working with lossy feed lines. IMO I consider a very long feed line a lossy feed line. That is why you're using hard line, as you call it, to cut down on those losses.

    You should check the SWR at or near the feed point as possible. I don't doubt that you're seeing 0 reflections. The longer the feed line the less SWR you will see at the TX'r end of the line...despite the expected low loss of your hard line.

    Taking a bandwidth reading with this long of feed line does not produce very productive information, and your numbers don't surprise me either. In fact the actual range in your case may be much greater than you suggest. You might be able to go down as far in frequency as you went up and still see a flat match at 1.1:1 SWR, maybe even a lot further if you have the capabilities. So, if very little SWR is reflecting back to your radio...then very little RF is probably getting up to the antenna in this case. IMO, this is due to OHMic loss in the form of resistance in the feed.

    Not to worry though, typically the Imax shows a really nice match and as long as you're getting out, nothing else matters.

    One day you should try and put a meter and a good dummy load on the antenna end of this 625' foot long line and check the throughput wattage? Even so, you may be surprised at how little wattage really gets up there. The only salvation is, it don't take much wattage to make a good workable signal if your RF pattern and signal path is good for your location.

    BTW, I would bet if you really check close, the noise level for your particular setup is really quiet also.

    Good luck and keep us posted.
    #2
  3. W5LZ

    W5LZ Crotchety Old Bastard

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    625 feet of feed line to the antenna? Really? And 'hard line'? You're kidding, right?
    - 'Doc
    #3
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  4. GnG8d

    GnG8d Well-Known Member

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    No, he's not.


    Sent from my iPhone using Tapatalk
    #4
  5. AudioShockwav

    AudioShockwav Extraterrestrial Admin Staff Member

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    I think he is Talking about Ladder line...If it is 600+ feet of Hard line I want to know were the gold is in the stream on the property ........

    ( ""hard line wire"" I read this as Ladder line)



    One needs impedance matching transformers at each end .


    73
    Jeff
    #5
  6. many folks also mistakenly refer to halex as hardline .
    #6
  7. GnG8d

    GnG8d Well-Known Member

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    No, I think he came across some heliax style transmission line as surplus. If I remember, it's has an aluminum shield vs copper.


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    #7
  8. W5LZ

    W5LZ Crotchety Old Bastard

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    'Ladder-line' I can believe, but have trouble believing the 'hardline' (unless it was given to your friend). Depending on the size of that hardline, you can 'make-do' with making your own connectors too. The local club just bought some 7/8" hardline half the length as was given, and at wholesale price. That's just not on my list of possibilities, I can't afford the @#$ connectors either!
    For VHF/UHF I can 'see' hardline, but not for HF. There's just no significant benefit.
    - 'Doc
    #8
  9. KingCobra_CDX882

    KingCobra_CDX882 W9WDX Amateur Radio Club Member

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    At that distance hardline ( even if Heliax) or Ladder Line coax is his only chance to get out reasonably given the distance from his radio to antenna (even on HF frequency's )
    #9
  10. GnG8d

    GnG8d Well-Known Member

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    You have trouble believing a lot of things.


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    #10
  11. W5LZ

    W5LZ Crotchety Old Bastard

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    359,
    You're right! And in most cases, I've got good reasons.
    - 'Doc
    #11
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  12. GnG8d

    GnG8d Well-Known Member

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    I just wish you'd learn to actually admit when you you are wrong. But in certainly not holding my breath.

    The man has posted several times that he got ahold if a large roll of aluminum shielded, heliax style coax.


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    #12
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  13. Marconi

    Marconi Supporting Member

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    359, I post a lot of images, just to prove the facts of what I'm doing or trying to say or describe all the time. Thank goodness we can post pictures.

    All Oatmeal has to do is post some pictures of this setup and the issue will go away. And if he don't do that, then disbelief will continue to raise questions.

    For years I've heard such tales from guys claiming they're using a very long feed line up on a mountain and calling it a mountain line, but I've never seen one show any evidence of such a setup. What is wrong with showing some proof?
    #13
  14. W5LZ

    W5LZ Crotchety Old Bastard

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    And please don't misunderstand, I have no reason to doubt him, I've never seen anyone's antenna over two football fields away from their house. Or, understood why you'd want one that far away.
    As far as admitting I'm wrong, all you have to do is convince me I am. I don't think that's unreasonable. Do you?
    - 'Doc
    #14
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  15. RatsoW8

    RatsoW8 Supporting Member

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    I grew up in WV and I helped a high school buddy do something like this. We had an air wound coax balun on each end and about 700 ft of ladder line in between run up the side of the mountain to a Radio Shack CLR-II antenna at 40 feet in pine tree we chopped off at about the halfway point.. Worked very well.

    Maybe by "hardline" he meant ladder line? I can't see doing a coax run that far.
    #15


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