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Re: [sierra_wilderness_radio] Re: Portable Antennas

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  • Frank MacDonell
    Tnx Don. I really appreciate your ideas. ... -- Sent from my mobile device Frank KD8FIP
    Message 1 of 3 , Feb 23, 2009
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      Tnx Don. I really appreciate your ideas.

      On 2/22/09, Donald McBride <McBride_D@...> wrote:
      > Hello Frank,
      >
      > RE: Antennas
      > Nothing is easier, as you know, than a simple half-wave dipole
      > fed with coax, and I have several depending upon what portable
      > rig I'm carrying to the field. However, my 25-year old 3-band
      > "jumper dipole" is my favorite. With sections separated by
      > insulators and small alligator clips, it can be quickly set for 20,
      > 30 or 40 meters by just temporarily lowering the center support
      > slightly.
      >
      > Perhaps like you, I've experimented with balanced line-fed
      > doublets and they certainly work, but coax is just so much
      > easier to pack and deal with and doesn't require a balun.
      >
      > Another antenna you may also have tried is the "Dollar Special"
      > found on the Internet at:
      > http://www.qsl.net/wb3gck/dollar_store_special.htm
      > While inflation has run that up to $2 these days, two packs of
      > Dollar Store speaker wire can be turned into a three-band
      > end-fed with tuned counterpoise and still wrapped up for
      > transit in a plastic sandwich bag. I carry mine all the time in
      > case something goes awry with my dipole, such as a broken
      > wire or forgotten whatchamacallit or whatever and have
      > worked the Ukraine with it from the park with my 2 watt SIERRA.
      > Oh, and did I mention that all these antennas are "cheap"? <grin>
      >
      > ... 72/73,
      > ... Don
      >
      >
      >
      >
      > <http://groups.yahoo.com/group/sierra_wilderness_radio/message/252;_ylc=X3oD
      > MTJxa21sc2I3BF9TAzk3MzU5NzE1BGdycElkAzIwMjE1MTY3BGdycHNwSWQDMTcwODM5NjM3OQRt
      > c2dJZAMyNTIEc2VjA2Rtc2cEc2xrA3Ztc2cEc3RpbWUDMTIzNTI5NTEyMg--> Re: Battery
      >
      >
      > Posted by: "Frank MacDonell" <mailto:kd8fip@...?Subject=
      > Re%3A%20Battery> kd8fip@... <http://profiles.yahoo.com/fmacdonell>
      > fmacdonell
      >
      >
      > Sat Feb 21, 2009 7:33 am (PST)
      >
      > Thanks Don - What kind of wire do you use? Do you cut to half wave?
      > What do you use for feeder wire? Thanks Again!
      >

      --
      Sent from my mobile device

      Frank KD8FIP
    • w9ya
      A couple of salient points about 1/2 wave antennas, baluns, and end-feds. There is no such thng as an end-fed with a counterpoise. i.e. Either an antenna is
      Message 2 of 3 , Feb 24, 2009
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        A couple of salient points about 1/2 wave antennas, baluns, and end-feds.

        There is no such thng as an "end-fed" with a counterpoise. i.e. Either an antenna is fed from one end or it is not, as the "counterpoise", when connected to a/the network (your antenna,rig, and tuner combination), **IS** a part of the antenna.

        And yes, sometimes center fed antennas may require a balun if a particular performance (pattern) is desired when used with coax. Why ? .... because coax is a three terminal transmission line, and the outside of a coaxs can radiate depending on various factors. (The specific length of coax being a common reason for such radiation and the use of baluns to mitigate this effect being a "solution".) This coax radiation will most likely be a departure from the classic resonant dipole pattern. (BTW this change may be an enhancement or a detraction depending on your desires for such an antenna. But it is real and a contributing factor in the resulting radiation pattern. And baluns are a great way to control coax radiation.)

        Bob
        w9ya

        On Sun, Feb 22, 2009 at 6:09 AM, Donald McBride <McBride_D@...> wrote:

        Hello Frank,
         
        RE: Antennas
        Nothing is easier, as you know, than a simple half-wave dipole
        fed with coax, and I have several depending upon what portable
        rig I'm carrying to the field. However, my 25-year old 3-band
        "jumper dipole" is my favorite.  With sections separated by
        insulators and small alligator clips, it can be quickly set for 20,
        30 or 40 meters by just temporarily lowering the center support
        slightly.
         
        Perhaps like you, I've experimented with balanced line-fed
        doublets and they certainly work, but coax is just so much
        easier to pack and deal with and doesn't require a balun. 
         
        Another antenna you may also have tried is the "Dollar Special"
        found on the Internet at: 
        While inflation has run that up to $2 these days, two packs of
        Dollar Store speaker wire can be turned into a three-band
        end-fed with tuned counterpoise and still wrapped up for
        transit in a plastic sandwich bag.  I carry mine all the time in
        case something goes awry with my dipole, such as a broken
        wire or forgotten whatchamacallit or whatever and have
        worked the Ukraine with it from the park with my 2 watt SIERRA.
        Oh, and did I mention that all these antennas are "cheap"? <grin>
         
        ... 72/73,
        ... Don
         
         

        Re: Battery

        Posted by: "Frank MacDonell" kd8fip@...   fmacdonell

        Sat Feb 21, 2009 7:33 am (PST)

        Thanks Don - What kind of wire do you use? Do you cut to half wave?
        What do you use for feeder wire? Thanks Again!

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