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RE: Loop on roof or in garden?

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  • Thomas F Giella W4HM
    It s not necessary to elevate a magnetic receive loop as the pattern is the same whether at ground level or 30 feet above ground. If you do elevate the receive
    Message 1 of 8 , Oct 4, 2013
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      It's not necessary to elevate a magnetic receive loop as the pattern is the
      same whether at ground level or 30 feet above ground. If you do elevate the
      receive loop the vertical or near vertical run of coax feedline will pick up
      noise in the local field which will defeat the S/N improvement that one
      normally looks for in this type of antenna.

      This problem can be pretty much solved by adding coaxial choke BALUNS at the
      feed point of the receive loop and at the radio shack service entrance. But
      it's not a fool proof solution.

      Check out my receive loop web page at http://www.wcflunatall.com/w4hm14.htm
      .

      73 & GUD DX,
      Thomas F. Giella W4HM
      Lakeland, FL, USA
      w4hm@...

      W4HM Amateur Radio & SWL Autobiography: http://www.w4hm.org
    • ilya_4z1uf
      DL2KQ says you MUST elevate the loop, especially if it is relatively large: http://dl2kq.de/ant/3-73.htm Please try to use Google Translator or any other. This
      Message 2 of 8 , Oct 5, 2013
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          DL2KQ says you MUST elevate the loop, especially if it is relatively large: http://dl2kq.de/ant/3-73.htm

         Please try to use Google Translator or any other. This is extremely interesting article, written by DL2KQ.
         For those who doesn't know: this guy published 6-part Antenna theory book, as well as re-build first the   known MMANA modeling SW, then  made a new one, GAL-ANA, which is very popular today among antenna manufacturers.
         I think that with only limitation -written in Russian- this web site is most comprehensive antenna-related web  site today.

         73,

        Ilya, 4Z1UF



        ---In loopantennas@yahoogroups.com, <loopantennas@yahoogroups.com> wrote:

        It's not necessary to elevate a magnetic receive loop as the pattern is the
        same whether at ground level or 30 feet above ground. If you do elevate the
        receive loop the vertical or near vertical run of coax feedline will pick up
        noise in the local field which will defeat the S/N improvement that one
        normally looks for in this type of antenna.

        This problem can be pretty much solved by adding coaxial choke BALUNS at the
        feed point of the receive loop and at the radio shack service entrance. But
        it's not a fool proof solution.

        Check out my receive loop web page at http://www.wcflunatall.com/w4hm14.htm
        .

        73 & GUD DX,
        Thomas F. Giella W4HM
        Lakeland, FL, USA
        w4hm@...

        W4HM Amateur Radio & SWL Autobiography: http://www.w4hm.org
      • ilya_4z1uf
        Sorry, some addition: one needs to elevate the RX loop in case we are talking about the roof of condos/apartment building. There is definitely no need doing so
        Message 3 of 8 , Oct 5, 2013
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          Sorry, some addition: one needs to elevate the RX loop in case we are talking about  the roof of condos/apartment building. There is definitely no need doing so if you are on the ground.


           73,

          Ilya, 4Z1UF 



          ---In loopantennas@yahoogroups.com, <loopantennas@yahoogroups.com> wrote:

          It's not necessary to elevate a magnetic receive loop as the pattern is the
          same whether at ground level or 30 feet above ground. If you do elevate the
          receive loop the vertical or near vertical run of coax feedline will pick up
          noise in the local field which will defeat the S/N improvement that one
          normally looks for in this type of antenna.

          This problem can be pretty much solved by adding coaxial choke BALUNS at the
          feed point of the receive loop and at the radio shack service entrance. But
          it's not a fool proof solution.

          Check out my receive loop web page at http://www.wcflunatall.com/w4hm14.htm
          .

          73 & GUD DX,
          Thomas F. Giella W4HM
          Lakeland, FL, USA
          w4hm@...

          W4HM Amateur Radio & SWL Autobiography: http://www.w4hm.org
        • John
          We moved in July to a garden home some 2.6 miles from my previous home in a community with a strict Home Owner s Association, including no external antennas
          Message 4 of 8 , Oct 5, 2013
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            We moved in July to a 'garden home' some 2.6 miles from my previous home in a community with a strict Home Owner's Association, including no external antennas save a satellite TV dish on the back of the house, and underground utilities. My previously low back deck mounted Pixel PRO-1A loop, fed with RG-6QS, went from outside mounted loop center at 8 ft above the ground and oriented to lessen the powerline/house wiring noise pickup to 22 ft above the slab inside my steeply inclined attic. Noise pickup is far less than the best days at my old home and local MW stations, WWV, R. Australia, etc, are as strong as before on both my Palstar R30A and Icom R75 - just more noise free. I did orient the loop to minimize dimmer noise pickup from the kitchen pot lights, but, as I am the cook, I just leave them off when I want to critically listen.

            I moved the loop & amp still connected to a 5 ft mast section - and quickly mounted the mast in a tripod mount resting on the attic's plywood floor. All the way up, I still would have 3-4 ft to the roof's ridge. I ran some RG-6QS to the area over my office where I found RG-6 leads from the two F female panel jacks in my room. It was super easy to feed the loop from behind my desk - thank you thoughtful house designer!

            The loop was tried at my old house after I lost my tall trees, longtime long wire supports, and could no longer null the powerline noise. It's great for nulling one source of QRM - like the high tension lines which ran in front of my old house - and resurrected my SWLing hobby. Putting it up from 8 ft to 22+ ft didn't seem to affect the signal strength - the underground services seem much quieter. My advice is to separate the loop from local noise sources and then minimize the pickup of same by rotating the loop. The height over ground shouldn't matter re signal pickup.

            Good listening!

            John
          • Myamiphil
            Translated and reformatted....google translator     Best Regards Phil Lat: 40.8367633  Long: -74.1768412   ________________________________ From:
            Message 5 of 8 , Oct 6, 2013
            Translated and reformatted....google translator
             
             
            Best Regards
            Phil
            Lat: 40.8367633  Long: -74.1768412
             



            From: "izozin@..." <izozin@...>
            To: loopantennas@yahoogroups.com
            Sent: Saturday, October 5, 2013 9:34 AM
            Subject: [loopantennas] RE: RE: Loop on roof or in garden?

             
              DL2KQ says you MUST elevate the loop, especially if it is relatively large: http://dl2kq.de/ant/3-73.htm
             Please try to use Google Translator or any other. This is extremely interesting article, written by DL2KQ.
             For those who doesn't know: this guy published 6-part Antenna theory book, as well as re-build first the   known MMANA modeling SW, then  made a new one, GAL-ANA, which is very popular today among antenna manufacturers.
             I think that with only limitation -written in Russian- this web site is most comprehensive antenna-related web  site today.
             73,
            Ilya, 4Z1UF


            ---In loopantennas@yahoogroups.com, <loopantennas@yahoogroups.com> wrote:

            It's not necessary to elevate a magnetic receive loop as the pattern is the
            same whether at ground level or 30 feet above ground. If you do elevate the
            receive loop the vertical or near vertical run of coax feedline will pick up
            noise in the local field which will defeat the S/N improvement that one
            normally looks for in this type of antenna.

            This problem can be pretty much solved by adding coaxial choke BALUNS at the
            feed point of the receive loop and at the radio shack service entrance. But
            it's not a fool proof solution.

            Check out my receive loop web page at http://www.wcflunatall.com/w4hm14.htm
            .

            73 & GUD DX,
            Thomas F. Giella W4HM
            Lakeland, FL, USA
            w4hm@...

            W4HM Amateur Radio & SWL Autobiography: http://www.w4hm.org


          • dx11
            Hello Thomas, We will certainly do some experimentations with common mode filters on the coax. The Web page you mention about your receiving loop was already
            Message 6 of 8 , Oct 7, 2013
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              Hello Thomas,

              We will certainly do some experimentations with common mode filters on the coax.

              The Web page you mention about your receiving loop was already in my collection of articles on the subject, I will read it again.

              Tnx,

               

              Cor Beijersbergen



              This problem can be pretty much solved by adding coaxial choke BALUNS at the
              feed point of the receive loop and at the radio shack service entrance. But
              it's not a fool proof solution.

              Check out my receive loop web page at http://www.wcflunatall.com/w4hm14.htm
              .

            • dx11
              Hello Ilya, That is to get away from the noise field coming through the roof from underneath? Cor Beijersbergen
              Message 7 of 8 , Oct 7, 2013
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                Hello Ilya,

                 

                That is to get away from the noise field coming through the roof from underneath?

                 

                Cor Beijersbergen

                 

                 

                >>>Sorry, some addition: one needs to elevate the RX loop in case we are talking about  the roof of condos/apartment building. There is definitely no need doing so if you are on the ground.<<<

                 

              • ilya_4z1uf
                Hello Cor, yes, correct. Thanks to Phil s correction you can see the full article in pdf. It stlll smells by goolge but quite readable. I will be glad to
                Message 8 of 8 , Oct 7, 2013
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                  Hello Cor,

                   yes, correct.

                   Thanks to  Phil's  correction  you can see the full article in pdf. It stlll smells by goolge but quite readable. I will be glad to re-translate any portion if needed.

                  73,

                  Ilya, 4Z1UF




                  ---In loopantennas@yahoogroups.com, <loopantennas@yahoogroups.com> wrote:

                  Hello Ilya,

                   

                  That is to get away from the noise field coming through the roof from underneath?

                   

                  Cor Beijersbergen

                   

                   

                  >>>Sorry, some addition: one needs to elevate the RX loop in case we are talking about  the roof of condos/apartment building. There is definitely no need doing so if you are on the ground.<<<

                   

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