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Thread: Portable antenna for 40, 60 and 80 m

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    Membership #: 321 Free member LA4TTA's Avatar
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    Portable antenna for 40, 60 and 80 m

    I've been scratching my head and searching the web for an (diy) antenna that is light enough for backpacking, siple to set up, efficient and covers 40, 60 and 80m.
    Preferably endfed.
    I'm close to the point where I'm starting to think that I should bring an separate antenna for 60m.

    So far the best solution i have tried is an 14m (ish) wire and an 9:1 unun with four different lengths radials.
    I have made an endfed windom ( http://51.175.186.36/la1dsa/Endfeed_windom.pdf for those of you that understand Swedish ) But it is quite heavy, and cumbersome to set up.

    Does anybody have any ideas and/or experience they would like to share it would be appreciated.
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    Erlend

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    Re: Portable antenna for 40, 60 and 80 m

    What about a link dipole? Easy to make multi band, no tuner required, no narrowing bandwidth from traps etc, and light. I use a 20/40 link dipole with a 8m fishing pole, works great. I guess for 80 meters a 10m pole might be better, but I can get 90degree apex angle on 40m at 8m.
    http://g1ybb.uk/first-portable-lightweight-link-dipole/
    Steve G1YBB
    http://g1ybb.uk

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    Re: Portable antenna for 40, 60 and 80 m

    That is an great suggestion. I already have an linked 12, 17, 20m dipole i use for sota. But this antenna will be more for camping use, and i would prefere not to have to leave the comfort of my sleeping bag to change bands. I should have mentioned that in my opening post.

    So far it stands between an dublett feed with 300ohm line and unun with an appropriate lengt of wire and counterpoise.

    Does anyone know if there will make annny difference if I connect the counterpoise to the unun vs grounding point of my radio? Does the coax lengt matter in respect to that.

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    Erlend

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    Re: Portable antenna for 40, 60 and 80 m

    Ah good point about not wanting to leave your sleeping bag.
    Don't know what power you are using but SOTAbeams have some very small (and light) traps.
    this is the 10W pico, they do 100W ones.
    http://www.sotabeams.co.uk/pico-traps-kit-pair/
    Steve G1YBB
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    Re: Portable antenna for 40, 60 and 80 m

    Quote Originally Posted by G1YBB View Post
    Ah good point about not wanting to leave your sleeping bag.
    Don't know what power you are using but SOTAbeams have some very small (and light) traps.
    this is the 10W pico, they do 100W ones.
    http://www.sotabeams.co.uk/pico-traps-kit-pair/

    I actually have inquired him about them, and it he seemed like he doubted that they could be made for 60m so I'm considering building from scratch. It's an valid option. Just not sure if I should try an dipole or 1/4 wave with radials.
    73
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    Erlend

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    Re: Portable antenna for 40, 60 and 80 m

    Quote Originally Posted by LA4TTA View Post
    I actually have inquired him about them, and it he seemed like he doubted that they could be made for 60m so I'm considering building from scratch. It's an valid option. Just not sure if I should try an dipole or 1/4 wave with radials.
    Ah Ok. I am a big fan of resonant antennas to save the weight and extra connections of an ATU.
    Same as qrp radio+linear v higher output radio. I like simplicity.
    Steve G1YBB
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    Re: Portable antenna for 40, 60 and 80 m

    Quote Originally Posted by G1YBB View Post
    Ah Ok. I am a big fan of resonant antennas to save the weight and extra connections of an ATU.
    Same as qrp radio+linear v higher output radio. I like simplicity.
    Agreed. Now my KX3 have an built in tuner that actually works so non resonant antennas is actually no problem. But I still would like to get most of my 10w out of my antenna, so efficiency is important to me. Also simplicity of erecting and using the antenna.

    Now. most of the areas suitable for camping in my part of Norway is mountains with little or no trees. This adds complexity to the "erecting the antenna" part. I will have to bring some sort of pole. An end-fed antenna could be erected in an inverted v or sloping configuration using a single pole. An dipole could also be erected using an single pole, but to get the ends at some height long guy lines must be used for an 80m antenna. So I think I will prefer end fed antenna to keep it simple.

    Thinking about it now as I write, I realise that I could build an trapped gp antenna, with three trapped radials and use two of the wires as an dipole when appropriate spaced trees are available.
    73
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    Erlend

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    Re: Portable antenna for 40, 60 and 80 m

    A trapped inverted L with lots of radials might be a solution. 10m Up and 10m Out for 80m, 60m trap half way along top section, 40m trap at junction of vertical and horizontal sections (at top of 10m pole). Bu tit might be a bit much to carry !
    Best 73 tu
    Peter G0DZB

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    Re: Portable antenna for 40, 60 and 80 m

    Quote Originally Posted by G0DZB View Post
    A trapped inverted L with lots of radials might be a solution. 10m Up and 10m Out for 80m, 60m trap half way along top section, 40m trap at junction of vertical and horizontal sections (at top of 10m pole). Bu tit might be a bit much to carry !
    The pole(s) Would weigh more than the wire. The pole weight vs radiation efficiency is poor from 6 to 10m antenna height I believe.

    I'm also looking at poles. It would be great to find a pole that would also support my tap. Maybe about 4m tall. Tie the tap some where up the pole an have the antenna feed point on the top. Then run the wire to another taller support.
    73
    de
    LA4TTA
    Erlend

  10. #10
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    Re: Portable antenna for 40, 60 and 80 m

    Quote Originally Posted by LA4TTA View Post
    The pole(s) Would weigh more than the wire.
    Use thicker wire then ! ;-) That will get the ratio back the "right way round" :-)
    The pole weight vs radiation efficiency is poor from 6 to 10m antenna height I believe.
    Radiation efficiency is far more to do with the earth system than the pole height. That's why I wrote "with lots of radials".
    I'm also looking at poles. It would be great to find a pole that would also support my tap. Maybe about 4m tall. Tie the tap some where up the pole an have the antenna feed point on the top. Then run the wire to another taller support.
    I'm sure you've seen these already : http://www.sotabeams.co.uk/compact-l...-m-30-ft-mast/
    PeterO
    G0DZB
    Best 73 tu
    Peter G0DZB

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