Thoughts please......Cobweb?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by G0HBS, Jul 2, 2020.

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  1. G0HBS

    G0HBS Ham Member QRZ Page

    G0HBS

    I have used a G5RV antenna from the start 1968, the one now in use a full size is not young say 5 years plus. I have had some good dx contacts through the years but it is possibly time for a change.
    I have no amp, so use 100w bare foot. Working the 40/20m bands seem ok,but a bit noisy. The 15/10m bands seem a bit deaf, 80m band is a bit difficult to tune and noisy. (It also switches on next doors bedroom led lights,
    ( thought it was funnier than the other party did) so only use it in the day.
    I have quite a large back garden for Britain but one end of the G5rvv disappears into the small wood at the back.
    I had thought of a spider beam/yagi but have been refused planning permission by the XYL due to size.
    I could get away with a cobweb 6/20m as it is smaller and a 40m dipole. An amp would not help the noise levels.
    Cheers Roger
    G0hbs
     
  2. AJ6O

    AJ6O Ham Member QRZ Page

    AJ5J likes this.
  3. N1LOU

    N1LOU XML Subscriber QRZ Page

    the G5RV has different radiation patterns depending on frequency and height above ground. Its not unusual for a G5RV to have a very high angle of take off on some bands, or have a very erratic horizontal radiation pattern with many nulls and lobes as you go around the compass. The nice aspect of the cobweb is that the radiation pattern doesn't really change with frequency since the individual elements are tuned to be near resonance. Depending on height above ground, the cobweb is almost omnidirectional, with no major lobes or nulls. I believe a cobweb mounted at about 35 feet will have decent take off angles on all bands as well. It's a pretty fair general use/compromise antenna. Probably the next best compromise antenna would be an inverted L.
     
  4. AJ5J

    AJ5J Ham Member QRZ Page

    I agree with Curtis, AJ6O, above; keep your G5RV and add a great vertical like a DX Commander ready for comparison at the flip of a switch.

    The cobweb is a fine omnidirectional dipole antenna but needs sufficient height for best performance (and I would think that it would only help you with whatever nulls you already have inherent in your G5RV installation, not a lot more otherwise).

    73,

    Jeff
     
  5. G0HBS

    G0HBS Ham Member QRZ Page

    Hi all ,thanks for your replies, AJ6O I will have a good look at your links.
    N1LOU I agree that the G5RV has a number of radiation lobes, I used to think that there was only 2 from the wire dipole. Over the last couple of years I have plotted the contacts and there seems to be 4 main lobes which tends to agree withe published plots.

    I am under the impression that verticals have a greater noise level than the cobweb/spider antennas (AJ5J) and I would like to loose some of that and maybe in the future buy an amp. What ever I do I still need to comply with local regulations Hi!. Though as you said it usually is best if possible to never remove antennas until you are sure.

    73's
    Roger
     
    AJ5J likes this.

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