Woud a disguised Cobweb work the same?

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by G1YBB, Sep 8, 2015.

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  1. N4UFO

    N4UFO Ham Member QRZ Page

    I used a plain old MFJ-259 to tune mine. Start with it at 6-10 feet out in the open. It may change some once you get it up higher, but usually not much. What causes bigger changes is moving near metal objects. (some other objects as well) Start with the lowest frequency and tune it first.

    GL!

    Kevin N4UFO
     
  2. G1YBB

    G1YBB XML Subscriber QRZ Page

    As Jeff AK5B suggests an analyser like the NanoVNA will really save you some hassle, and make it fairly painless. They are cheaper than an MFJ analyser and the graphical plot is very informative. You could do it with an MFJ but mine has remained unused since I got a graphical analyser. I actually use the MetroPwr FX700 now as I wanted 432MHz coverage and I didn't like the NanoVNA when not being driven via USB on a PC (then it is brilliant!)
    For actual tuning I measured each wire on each lift up into free space and noted the resonance on paper in a little table, pulled it down, snipped a small amount off each one to start (same each one) and re-measured to see how much wire off changed each one and worked from there.
    I detailed my method and findings here:
    https://g1ybb.uk/g1ybb-disguised-ultralight-cobweb-antenna/

    I always like to work slowly and methodically.
     
    AK5B likes this.
  3. KG7WGX

    KG7WGX XML Subscriber QRZ Page

  4. WA6FYD

    WA6FYD Ham Member QRZ Page

     
  5. WA6FYD

    WA6FYD Ham Member QRZ Page

    Timely info but I intend to keep the flat design little bugger only 10 ft high and my HMO conveniently built a nice wall and there is no direct view into my backyard. I'm more worried about the NanoVNA - sounds like an an antenna pattern. I do have an ancient MFJ that may still work. Now if the HMO doesn't have a drone I may be able to get this done. Presently I'm using a 20 MTR dipole at 7ft around my fence. Thanks every body.
     
  6. KL7AJ

    KL7AJ Ham Member QRZ Page

    I've used countless disgusted antennas with good results.
     
    AK5B likes this.
  7. AK5B

    AK5B Ham Member QRZ Page

    Even though you've gotten good results you might want to quit making them with Copperweld, just a thought...
     
  8. G1YBB

    G1YBB XML Subscriber QRZ Page

    If it still works you can use that. I'd still measure each band in one go and find the dip on each and note it, to minimise the ups and downs while you tune.
    My FX700 will actually measure 5 bands at once which is neat though I tend to not use that screen and do one band at a time at a larger scale.

    upload_2021-3-23_16-16-9.png
     
    SM6CJB likes this.
  9. WA6FYD

    WA6FYD Ham Member QRZ Page

    Haha. I still had the best results with a Traffie 5-band Hexbeam (no longer in biz). It was like having already tuned circuits right out of the box. But I am thinking of using the FX700/FX1300 Steve mentioned and try the multi shot.
     
    G1YBB likes this.

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