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Thread: The M0LMK "UglyBug"

  1. #1
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    The M0LMK "UglyBug"

    The M0LMK "UglyBug" antenna is designed as a multi band bug catcher style antenna for /M and /P operating.

    It's built from an old monoband HF mobile antenna from the Pro AM range (sometimes called Hamsticks) and 2 custom made air wound coils.

    The lower mast section of the is stripped of it's plastic wrap and the helically wound wire is replaced with a single strand of 2mm copper which stops 6" below the top of the section and is terminated with a 8" flying lead and crocodile clip.
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    The main coil is wound on a 4" diameter x 6" tall former and wound with 2mm copper wire at 5 turns per inch.
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    The coil is held onto the lower mast with the lower part of a 3/8" quick release connector.
    Click image for larger version. 

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    The base coil is used to add some much needed inductance on the lower bands. It can be switched in and out. It is 1.5" diameter x 1" tall with 6 turns of 2mm copper wire.
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    The whip section is placed on to and the antenna is tuned by tapping the main coil at different points to achieve the best match for the band you are using. I have marked the tapping points with finger nail polish (M6WFY, my wife, won't be happy when she finds out!)

    Here is version 1 installed on the roof of the car for static /M.
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    It works well on 40M up to 10M even though I've managed to tune it using only a SWR meter! I'm sure it will perform much better once I can get a antenna analyser on it and I can tune the base coil for best match on all bands. 40M is a little narrow but it just requires a quick retap of the coil if you are moving up and down the band.

    I've used the "UglyBug" both on the car roof and on a 6" tall mast with several random length radials. Both methods seem to work about the same, performance wise.

    Version 2 will have a bigger main coil and a sturdier base coil.

    Keep watching this thread for details.
    Matt - M0LMK


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    mu0chn (28th Apr 2015),WD5IKX (2nd Aug 2015)

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    John Love
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    Re: The M0LMK "UglyBug"

    I don't think it is "Ugly"....I think it is "purdy" (pretty - with a heavy Texas drawl) I happen to like my HF antennas "Big & Ugly" so I guess it is true when they say... "beauty is in the eye of the beholder".

    Thanks for sharing.

    John
    WD5IKX

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    Re: The M0LMK "UglyBug"

    Version 2 has 6' x 10' coil former which is laser cut from acrylic.

    I'll post more details once I have found someone to laser cut it for me!
    Matt - M0LMK


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