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Loop-On-Ground Antenna

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by AI5DH, Aug 1, 2018.

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  1. N5YPJ

    N5YPJ QRZ Moderator QRZ Page

    Like most antennas, everything"works". The real question is how good does it work compared to other antennas.

    Don't want to hijack the thread and no I can't seem to find a way to insert a quote here LOL. Anyway I understand what Jerry said. For most of my 40+ years as a ham I have had less than optimum antennas often just a wire or a trap vertical (I thought I was living large when I could switch back and forth between a dipole and the vertical see which had the better sig) so I never knew what a good antenna was to know how poorly my 25 or 30 ft wire was performing. Many hams have to improvise what space, neighborhood restrictions and finances allow for and some of those folks have done quite well in contests and DX chasing others have not. Not many of us have enough room to properly compare antennas so to know what works and what doesn't.

    Newcomers to AR often ask what is the best antenna? The best antenna is the antenna that one is able to put up, installed safely where it can cause no harm like a trip hazard or RF burn following good engineering practices. Having experienced no antenna before any antenna is better than none.

    For my 40 X 45 ft clear area the Loop on Ground works for me. Jerry says it is less than optimum and I believe him but I do not have room for anything else in the line of receiving antenna and my noise level is S-9/+ on a transmit antenna. I put new DX in the log / LoTW using LoG and my mag loops. The LoG works how well compared to the other antennas mentioned? I may never know except to take Jerry at his word which I do. Live and let live! :)
     
    SWL37632 likes this.
  2. WN6F

    WN6F Ham Member QRZ Page

    TEST your LOG:

    Jerry gave me a great idea that I used in the past with small vertical loops, where a convenient point-source of noise was needed for test.

    IF your log isn't surrounded by neighbors and you have the space, test the directivity. Unfortunately, I don't as this test would put me in my neighbors living rooms. :)

    Get a battery-operated drill. No actual bit needed. Tape or lock the trigger to activate drill motor. Maybe keep spare charged drill battery handy.

    Place running drill motor on a small stepstool many feet away from the log. Don't place it too high, like on top of a ladder, or you'll be emulating a skywave signal. Most likely need to turn on rig's attenuator first. Move stepstool with drill motor at various places around the log. You should witness a null at some point.

    If you don't, then check for common-mode issues from the transmission line. May need to improve your grounding or choking to obtain a null.

    Option: go nuts with a spreadsheet and Terman handy. Or not. :)

    Stop reading forum, and get your boots out on the ground.
     
    N5YPJ likes this.
  3. SWL37632

    SWL37632 QRZ Member

    Good tip..... a 'broadband' noise emitter.
     
  4. WA7ARK

    WA7ARK Ham Member QRZ Page

    Is the RFI vertically or horizontally polarized, or does it depend on how you hold the drill???:D
     
    N0TZU, 2E0CIT and N5YPJ like this.
  5. WA4SIX

    WA4SIX Ham Member QRZ Page

    It's circularly polarized.

    Ed
     
    N0TZU, N6YWU, 2E0CIT and 3 others like this.
  6. W9IQ

    W9IQ Ham Member QRZ Page

    It doesn't matter one bit.

    - Glenn W9IQ
     
    KP4SX likes this.
  7. SWL37632

    SWL37632 QRZ Member

    In some of my untuned loop+amp configurations, I've noticed the same thing.

    Reflecting on the 'sharing' in this thread, I wonder if much or some of this 'noisy smoke' is rooted in stuff above 30 MHz such as from Public Service /FM / TV emitters.....

    Rationale: While doing some 2m sat experiments last year, adding a bandpass filter resulted in a significant reduction of 'noisy smoke', which was not attributed to the normal and expected baseband noise. My conclusions were the stuff was primarily FM broadcast stuff in my environment.

    Seems like adding a lowpass filter ahead of the amplifier might be an interesting experiment to perform for this 'noisy smoke'...
     
    N5YPJ likes this.
  8. SWL37632

    SWL37632 QRZ Member

    Curious to know if you could give some numbers to the lower noise floor?
     
  9. N5YPJ

    N5YPJ QRZ Moderator QRZ Page

    I think that might be next thing I try.
     
    SWL37632 likes this.
  10. N5YPJ

    N5YPJ QRZ Moderator QRZ Page

    Been wondering this for a while. Would the RFI be radiating on the powerl ines coming into our house and my shack as in something that might could be choked in the breaker panel box .... or is it radiating in neighbors' wiring being pick up by my rig? Reason for asking much of our power distribution in the neighborhood is original 1960's only changed out as it fails.
     
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