wire antennas

Discussion in 'Ham Radio Discussions' started by W4CUM, Sep 1, 2017.

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  1. W4CUM

    W4CUM Ham Member QRZ Page

    W4cum in north alabama..My place is treeless for the most part,,,1200' east to west,,and 340' north to south. I dont plan to transmit more than 100 watts,,,,I have 4 towers on the ground each about 40' long when erected, plus 3 wooden city light poles about the same length. What im asking is guidance please. I want to erect
    --1. a horizontal loop or series of loop antennas one within the other or --maybe just expand a loop to really large size 240m around or 400m around and then tune for 80m used,,,and then for higher frequencies tune for those also. If I cut it for a much larger loop size of 400m so it can take several waves at once of 80m am i defeating my purpose? I figure the larger the better on a receive signal, but on a transmit, trying to do so with many waves at one time may not be the thing to do. Im wanting to do 80 40 20 and 10 m.
    ---2. Instead of this or in addition to it,,,how about a V or several Vs in different directions on these poles. Do i want to cut them for multiple waves or just max out at 80m and go with that?
    --3. Should i go for several dipoles in different directions?
    --4. I have room for a rhombic if i dont go on too low a frequency,,is that the way to go? I get lots of piecemeal information at this end from operators, but no one it seems has the real estate I do and none of them have tried it. Any suggestions are greatly appreciated,,,,also at bill45colt@yahoo.com,,,,i have several antenna books but none seem to address these questions......thanks fellas!!
     
  2. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    Are you looking for DX, local/regional comms, or both?

    A horizontal full wave 80 M loop will be a GREAT local/regional antenna at 40 ft AGL. When tuned to 40/20/10 the radiation pattern will lower for better DX.

    80M loop at 14 MHZ:
     
  3. KM4DYX

    KM4DYX XML Subscriber QRZ Page

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    K6LPM likes this.
  4. WB2WIK

    WB2WIK Premium Subscriber QRZ Page

    You could try a rhombic, but it's a directional antenna and if terminated, aims in just one direction; so unless you want to work stations in only one direction, it really takes about 12 rhombics (with a switch) to work stations in "all" directions.

    W6AM had at least 16 rhombics up, but not with a 1200' lot and not with only 40' poles; Don had 60 acres and his supporting poles were mostly 90 to 120 feet high.

    Reason most don't bother doing this is a single rotatable beam can do about as well and occupy a lot less space. The W6AM "rhombic farm" was a sight to behold (I visited it, twice), you could see the poles from miles away...but I think the reason he did that is most of the rhombics were already there, as he bought a site that was set up for military use in the 1930s and that was before hams really had "beams."

    With a lot that size, I'd go for a beam or two (or three) on rotators, and keep them closer to the house so feedlines don't have to be so long, and call it a day.
     
  5. W6OGC

    W6OGC Ham Member QRZ Page

    I have a loop 280' around, matched with an Icom AH-4, at ~32-38'. The AH-4 gives a good match in all bands. It is not a particularly great antenna, I suspect because of it's low height. I imagine that at 60' it would be a great deal better.

    One factor I seldom see mentioned is eliminating inefficiencies. Short coax runs, solid connections, adequate wires size, good quality coax, etc., maybe balanced feed lines to a high quality low loss balun.

    I fret over such things because I run 5 watts, and every db is precious.

    I've never read that you gain anything by making a loop bigger.
     
  6. KM4DYX

    KM4DYX XML Subscriber QRZ Page

    I'm with you there, 5 watts is my max and I try to squeeze every bit out of it.

    The OP seems to be cursed with a huge patch of land to build antennas on, and is not sure of how to proceed.

    Oh to have such a problem!

    73,
    Al
     
    WA8FOZ, N1EN and W5TTP like this.
  7. W1VT

    W1VT Ham Member QRZ Page

    I'd suggest you put up verticals or Inverted-Ls for 160 and 80 transmit. And devote most of your effort to optimizing receive antennas and eliminating local noise sources. Experiment to see what works for you. Put up a Beverage toward Europe and use it as a standard of comparison against other options, such as receiving loops and active antennas. If some of these options don't seem appropriate for your particular circumstances, try something else. Once you figure out what works for you, you can work on covering all directions.

    https://www.w8ji.com/antennas.htm
    Tom has lots of info on his web site.

    ON4UN has a popular printed book that is mostly about antennas.

    Zack W1VT
     
  8. KK6NOH

    KK6NOH Ham Member QRZ Page

    I would do a run of wire 1092 feet long in a horizontal loop form. That is 2x wavelength on 160 meters. When you have 2x wavelength or more in your loop the angle of radiation lowers to be better for DX. If you have 1x wavelength or less it turns into a NVIS antenna.

    1092 feet in a loop gets you 160-10 with DX radiation pattern and very little noise. Easy to tune too.
     
  9. KA2UFP

    KA2UFP Ham Member QRZ Page

    ... put 15 meters on list ... great band, no amps needed, 3-4 way communications, as par antennas look at no tuner needed OCF dipoles Buckmaster, end feds are much improved to the max .... EFHW 80-10 My Antennas work excellent and no tuner needed ...
     
  10. W6OGC

    W6OGC Ham Member QRZ Page

    Doesn't height enter into this?
     

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