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Thread: Long wire question

  1. #1

    Default Long wire question

    Hi guys, new here with some questions, after checking around this forum I noticed there is quite a world of combined experience from all members sooooo here we go. Please note that I am quite new to shortwave antennas. And for listening purposes I try to build one, when I was very young I used to listen to shortwave with a old Russian transistor radio VEF 206 and like it a lot but now I have the shortwave listening bug again and have a few questions.
    I plan to run a 80 ft 14ga insulated copper stranded wire a couple of feet over a privacy wooden fence (I reside in a HOA subdivision) so I canít go too high, and the main question I have is if I could continue the same long wire straight after tied up to the porcelain insulator (whitout cutting it) to the a 9:1 balun I have or if I should cut the wire after attached to the porcelain insulator and splice the long wire a few feet from the porcelain insulator and wrap and solder de lead wire to run it down to the balun? I donít know if there is a benefit to this or not, After that I plan to use a 65 feet rg58 with Pl259 ends coax that I had for a while to a Grundig Satellit 750 radio I have. Iím sure I have more questions but I would like to start with this for now, thanks for your response in advance. Ricky.

  2. #2
    Super Moderator 5B4AJB's Avatar
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    I would try it without the balun and use a simple ATU. Your mileage may vary (as with a lot of antenna-type things)!

    Long wires tend to be very noisy antennas, but, keep it away from objects and it should be OK. I recommend about 2 feet of insulator at either end of the wire (fishing line etc) before it gets tied off.

    Erect it without the balun and test its performance, if you find it doesn't do what you need, then fit the balun...

  3. #3

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    Couldn't find any sensitivity or dynamic range specifications for that radio on the internet. Apparently front end overload and intermod are problems. You may need less antenna rather than more.

  4. #4

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    What about using the ARRL Antenna manual or The ARRL Radio Amateur Handbook. There is free link available online..

    A Long Wire antenna would be several wavelength long - I doubt if you have the real estate to put up something like that..

    Focus on building some type of dipole antenna, feed it directly with 75 ohm coax. No need for a Balun for a receive antenna..

  5. #5

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    Reviews for this radio were POOR at best!-- https://www.eham.net/reviews/detail/7256

  6. #6

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    5B4AJB nailed it. If you are receiving only, a balun would just be an extra loss. A dipole would be best but is very sensitive to the band it is cut for and not so much multi-band reception. Back in the day when I just listened, I used a strand of 16 gauge copper wire (insulated as the insulation is invisible to RF) 100' long that ran out the window, along the house, and 12' up a tree. The problem with a random length long wire is that it will be resonant at many points, which translates to noisy. Good luck on a great hobby!

  7. #7

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    Quote Originally Posted by Tempstar View Post
    ... the insulation is invisible to RF...
    Insulated wire has a different velocity factor than the same bare wire meaning that insulation is not completely invisible to RF.

  8. #8

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    "Insulated wire has a different velocity factor than the same bare wire meaning that insulation is not completely invisible to RF."

    Right, VF being 95-99% for insulated copper strand without shielding, such as the wire found in ladder line. Since the OP is talking random length wire and not a ladder line with it's small capacitance between the legs, and since we use the reciprocal of the square root of our dielectric constant, one will find the VF to be so close to 100 as to be virtually invisible to RF. If we're really gonna split hairs here, bare copper, once exposed to the elements, will exhibit a velocity factor as well due to corrosion build up over time, and since we all know that RF travels over the surface of a conductor, bare copper will be a far worse choice after a period of just a few weeks in most climates.

  9. #9

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    You might get some use out of one of those loop antennas you see advertised as a do all antenna - if all you want to do is listen..

    The problem is - what are you going to listen to? Most countries has already shut down their long wave transmitters and moved everything onto the internet.

  10. #10

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    Thanks everybody for your responses, I have put up the long wire with the balun (have not tried without it) and got pretty good reception all the way from Asia, European Countries, a few Middle East countries, a few South American countries including Argentina, plus Cuba of course (you can pick Cuba with your finger on the antenna port) and some of those stations I picked when tried a 102 Whip on a 20 inch pipe would not come up near as clear as with the long wire plus some stations I could not even pick up with the whip soooo I`m happy with the results. Thanks again for your help and recommendations.

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