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Does a fence antenna work?

Discussion in 'Amateur Radio News' started by KD5W, Jul 6, 2024.

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  1. KD5W

    KD5W XML Subscriber QRZ Page

    After seeing people ask online if they could string a wire on top of their fence and use it as an antenna, I decided to see how it would work. While there are definitely better antenna options available, this method can get you on the air, especially if you're living in a strict HOA environment. However, be cautious about placement to ensure no one can get too close to the wire and do your exposure calculations. Would be best to not put it on a shared fence. Additionally, keep in mind that if your fence gets wet, it will detune the antenna significantly.

    KC1RVK likes this.
  2. WE8TOM

    WE8TOM Premium Subscriber QRZ Page

    I'm "on the fence" about this one!
    VK5OHR, WA1LBK, 2E0CIT and 3 others like this.
  3. ND5Y

    ND5Y Ham Member QRZ Page

    K0UO likes this.
  4. K7JQ

    K7JQ Ham Member QRZ Page

    If your fence is metal, mount a motorized screwdriver antenna on it, using it as the counterpoise. 10-80 meters, 1.5:1 SWR (or less) across all frequencies. Low enough profile so no one should complain. You’ll be surprised how well it works.
    K0UO likes this.
  5. VK5OHR

    VK5OHR Ham Member QRZ Page

    My Icom AH-4 random length wire auto tuner has tuned a fence, gutter, defunct telephone line, car door, farm gate, rain water tank and a metal roof.
    JK1WPS, WA1LBK and M6ECG like this.
  6. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    His wire on that fence is very inefficient, it's heating up the worms.
    It still might receive pretty good, and he may have low SWR. So it also works as a good dummy load.... ..

    You can get about anything to load up, and make some contacts, but it's questionable if it's a good antenna or not!!
    The laws of physics apply, no matter what your SWR is.

    He made some good points about not using on a shared fence for safety reasons. Also rain and weather conditions would be a constant loading problem.

    A vertical mounted on there using the wire on the fence as a ground system system, would be a better choice.
    Last edited: Jul 7, 2024
    K1TGX likes this.
  7. N6YWU

    N6YWU Premium Subscriber QRZ Page

    • Any antenna is better than no antenna. Verticals or using trees might not be allowed or safe in some settings.
    • One can make contacts with a low NVIS antenna, even at QRP power levels, possibly even some DX with FT8 or CW.
    • The portion of the pattern opposite the worm heating does radiate upward for NVIS, often better than a vertical for local HF.
    • For receive, a lower noise antenna is better than a high noise one (if you can't hear 'em, you can't work 'em). And, in urban settings, a low horizontal antenna, or even one lying on the ground, might show better weak signal SNR than a vertical.
    My WSPR antenna is a back fence EFHW at 7' AGL, and using only 1 Watt, occasionally gets spotted by distant DX.
    WA1LBK, N8TGQ and K0UO like this.
  8. K0UO

    K0UO Platinum Subscriber Platinum Subscriber QRZ Page

    I never said you couldn't make contacts, in fact I said you could.

    I totally agree with you, the Best antenna is one that's On the Air and making QSOs.

    The frustration level can be higher though, with such a low configured system.

    The laws of physics apply, no matter what your SWR is.
    WA1LBK likes this.
  9. N6YWU

    N6YWU Premium Subscriber QRZ Page

    Has anyone compared the pattern efficiency of a low NVIS horizontal (40M EFHW) vs. a short vertical such as a rear bumper screwdriver or 7' hamstick?
  10. K7JQ

    K7JQ Ham Member QRZ Page

    I can't give you pattern efficiency between the two, but I can give my experience.

    In my HOA, for years I've been running a Tarheel screwdriver mounted directly in the middle and on top of a 70'x 6' steel fence bordering the back of my property, using just that as a counterpoise. The tube that encases the motor and coil is 4 feet, and the whip is 6'...not enough visibility to rattle anyone's cages in the neighborhood nor the HOA. In my post above, I indicated its SWR all over 10-80 tuner needed. In the case of a wooden fence, just run a series of radial wires, fanning directly out beneath the antenna both ways along the fence.

    Ignoring stats like radiation pattern and efficiency, I've worked all over the world in CW, SSB, and RTTY contests, running 100W. I don't do FT8 or any other digital stuff. No muss, no fuss, easy install. That's what counts...*reliably working stations* with a low profile, low footprint antenna, not affected by the elements of weather.

    I have another screwdriver ground-mounted high on a hill behind the house, hidden in desert brush, with sixty 25' radials stapled to the ground, running legal limit. Close to 300 countries worked and decent contest scores...obviously a more optimal location than the one on the fence.
    Last edited: Jul 8, 2024 at 12:22 AM
    VK5OHR, N0YXB, WA1LBK and 2 others like this.

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