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Re: [loopantennas] c-crane dual coil antenna?

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  • kevin asato
    It s similar to what xtal radio developers have been using - multiple air-wound coils in the same plane to help increase sensitivity to their crystal sets. The
    Message 1 of 8 , Jul 4, 2013
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      It's similar to what xtal radio developers have been using - multiple air-wound coils in the same plane to help increase sensitivity to their crystal sets. The use of the ferrite bar allows a reduction in the coil size. Difference is that the crystal sets do not fix the position of the coils to allow for fine tuning of signals. I do similar using a Terk Advantage coil with my portable radios. It works but it is not a miracle worker.
      73,
      kevin
      kc6pob


      From: Don <stb55@...>
      To: loopantennas@yahoogroups.com
      Sent: Thursday, July 4, 2013 5:03 AM
      Subject: Re: [loopantennas] c-crane dual coil antenna?

       
      Hi Steve,

      Thanks! I did not know you did that investigation. I bought one a couple
      of years ago to hopefully improve the AM reception of my stereo in this
      metal can. The "twin-coil" was also about half price. Anyway, it did not
      help/improve reception in my case.

      Don KPC6NDB
      Upland, CA
      34.10 -117.63 1250ft
      R-75 w/250Hz 2x R-71A w/250Hz R-70
      Perseus SDR-IQ FUNcube Dongle Pro+
      FRG-100B DX-1000 SR-AF & LPF
      DSP599zx MFJ-784B HD-1418 AF-1
      MSB-1 PA0RDT Mini-Whip x2 @ 20ft
      RYO Active Antenna @ 20ft
      LFL1010 ALA100L x2

      On 03-Jul-13 22:36, Steve Ratzlaff wrote:
      >
      >
      > This same topic came up several years ago. At that time I bought the
      > Twin Coil antenna and tore it apart and tested it extensively on the
      > bench. I used both the original twin coil then replaced it with a single
      > coil. In all tests, there was no significant difference, if any
      > differences at all, between the two configurations. And reading the
      > patent, there are glaring errors seemingly purposely inserted to try to
      > fool the unwary. It's a good antenna for its 7.5" ferrite rod size and
      > works well and I recommend it if one needs a 7.5" ferrite rod remotely
      > tunable antenna. But if you homebrew your own using a similar 7.5" rod
      > from Amidon, and the standard single coil, you'll get the same
      > performance. There is no magic at all in the use of "twin coils". If
      > anything, it appeared the technician on the factory production line
      > could more easily and quickly adjust the antenna for the proper tuning
      > range, compared to a single coil--perhaps that's the main reason why the
      > "twin coil" continues to be made.
      > 73,
      > Steve AA7U
      >


    • tmckee_k4zad
      Kevin, I would much appreciate it if you would supply links to a site or two where one can learn more about Xtal set builders use of multiple air-wound coils
      Message 2 of 8 , Jul 5, 2013
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        Kevin,

        I would much appreciate it if you would supply links to a site or two where one can learn more about Xtal set builders use of multiple air-wound coils in the same plane.

        Thanks,

        Tom
        K4ZAD

        **************************************

        --- In loopantennas@yahoogroups.com, kevin asato <kc6pob@...> wrote:
        >
        > It's similar to what xtal radio developers have been using - multiple air-wound coils in the same plane to help increase sensitivity to their crystal sets. The use of the ferrite bar allows a reduction in the coil size. Difference is that the crystal sets do not fix the position of the coils to allow for fine tuning of signals. I do similar using a Terk Advantage coil with my portable radios. It works but it is not a miracle worker.
        >
        > 73,
        > kevin
        > kc6pob
        >
        >
        >
        > ________________________________
        > From: Don <stb55@...>
        > To: loopantennas@yahoogroups.com
        > Sent: Thursday, July 4, 2013 5:03 AM
        > Subject: Re: [loopantennas] c-crane dual coil antenna?
        >
        >
        >
        >  
        > Hi Steve,
        >
        > Thanks! I did not know you did that investigation. I bought one a couple
        > of years ago to hopefully improve the AM reception of my stereo in this
        > metal can. The "twin-coil" was also about half price. Anyway, it did not
        > help/improve reception in my case.
        >
        > Don KPC6NDB
        > Upland, CA
        > 34.10 -117.63 1250ft
        > R-75 w/250Hz 2x R-71A w/250Hz R-70
        > Perseus SDR-IQ FUNcube Dongle Pro+
        > FRG-100B DX-1000 SR-AF & LPF
        > DSP599zx MFJ-784B HD-1418 AF-1
        > MSB-1 PA0RDT Mini-Whip x2 @ 20ft
        > RYO Active Antenna @ 20ft
        > LFL1010 ALA100L x2
        >
        > On 03-Jul-13 22:36, Steve Ratzlaff wrote:
        > >
        > >
        > > This same topic came up several years ago. At that time I bought the
        > > Twin Coil antenna and tore it apart and tested it extensively on the
        > > bench. I used both the original twin coil then replaced it with a single
        > > coil. In all tests, there was no significant difference, if any
        > > differences at all, between the two configurations. And reading the
        > > patent, there are glaring errors seemingly purposely inserted to try to
        > > fool the unwary. It's a good antenna for its 7.5" ferrite rod size and
        > > works well and I recommend it if one needs a 7.5" ferrite rod remotely
        > > tunable antenna. But if you homebrew your own using a similar 7.5" rod
        > > from Amidon, and the standard single coil, you'll get the same
        > > performance. There is no magic at all in the use of "twin coils". If
        > > anything, it appeared the technician on the factory production line
        > > could more easily and quickly adjust the antenna for the proper tuning
        > > range, compared to a single coil--perhaps that's the main reason why the
        > > "twin coil" continues to be made.
        > > 73,
        > > Steve AA7U
        > >
        >
      • kevin asato
        As requested. Not trying to be a smart-A but these are two that popped up readily. http://antiquewireless.org/otb/dxxtal.htm
        Message 3 of 8 , Jul 5, 2013
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          As requested. Not trying to be a smart-A but these are two that popped up readily.

          http://antiquewireless.org/otb/dxxtal.htm
          http://members.shaw.ca/ve7sl/crystal.html

          If you notice the coil construction, there are a couple of techniques being used. One is a basketweave type construction and the other is the normal spiral wrap on a coil form. By not having the coils fixed in place as in the Twin Coil design, you can adjust the coupling between the coils to peak what you are trying to listen to. I suppose you could manage to alter the distance between coils on the Twin Coil design but then you would not be able to use the weather proof case for remote mounting! I suppose you can probably come up with similar results using separate loopstick antenna coils.

          Makearadio.com has instructions on winding basketweave antenna coils, larger frame type coils, and spider coils.
          73,
          kevin
          kc6pob

          From: tmckee_k4zad <mckeetajc@...>
          To: loopantennas@yahoogroups.com
          Sent: Friday, July 5, 2013 7:41 AM
          Subject: [loopantennas] Re: c-crane dual coil antenna?

           
          Kevin,

          I would much appreciate it if you would supply links to a site or two where one can learn more about Xtal set builders use of multiple air-wound coils in the same plane.

          Thanks,

          Tom
          K4ZAD

          **************************************

          --- In loopantennas@yahoogroups.com, kevin asato <kc6pob@...> wrote:
          >
          > It's similar to what xtal radio developers have been using - multiple air-wound coils in the same plane to help increase sensitivity to their crystal sets. The use of the ferrite bar allows a reduction in the coil size. Difference is that the crystal sets do not fix the position of the coils to allow for fine tuning of signals. I do similar using a Terk Advantage coil with my portable radios. It works but it is not a miracle worker.
          >
          > 73,
          > kevin
          > kc6pob
          >
          >
          >
          > ________________________________
          > From: Don <stb55@...>
          > To: loopantennas@yahoogroups.com
          > Sent: Thursday, July 4, 2013 5:03 AM
          > Subject: Re: [loopantennas] c-crane dual coil antenna?
          >
          >
          >
          >  
          > Hi Steve,
          >
          > Thanks! I did not know you did that investigation. I bought one a couple
          > of years ago to hopefully improve the AM reception of my stereo in this
          > metal can. The "twin-coil" was also about half price. Anyway, it did not
          > help/improve reception in my case.
          >
          > Don KPC6NDB
          > Upland, CA
          > 34.10 -117.63 1250ft
          > R-75 w/250Hz 2x R-71A w/250Hz R-70
          > Perseus SDR-IQ FUNcube Dongle Pro+
          > FRG-100B DX-1000 SR-AF & LPF
          > DSP599zx MFJ-784B HD-1418 AF-1
          > MSB-1 PA0RDT Mini-Whip x2 @ 20ft
          > RYO Active Antenna @ 20ft
          > LFL1010 ALA100L x2
          >
          > On 03-Jul-13 22:36, Steve Ratzlaff wrote:
          > >
          > >
          > > This same topic came up several years ago. At that time I bought the
          > > Twin Coil antenna and tore it apart and tested it extensively on the
          > > bench. I used both the original twin coil then replaced it with a single
          > > coil. In all tests, there was no significant difference, if any
          > > differences at all, between the two configurations. And reading the
          > > patent, there are glaring errors seemingly purposely inserted to try to
          > > fool the unwary. It's a good antenna for its 7.5" ferrite rod size and
          > > works well and I recommend it if one needs a 7.5" ferrite rod remotely
          > > tunable antenna. But if you homebrew your own using a similar 7.5" rod
          > > from Amidon, and the standard single coil, you'll get the same
          > > performance. There is no magic at all in the use of "twin coils". If
          > > anything, it appeared the technician on the factory production line
          > > could more easily and quickly adjust the antenna for the proper tuning
          > > range, compared to a single coil--perhaps that's the main reason why the
          > > "twin coil" continues to be made.
          > > 73,
          > > Steve AA7U
          > >
          >



        • tmckee_k4zad
          Kevin, Many thanks. From your earlier message I assumed that you had more information about the Xtal set builders at hand than you did, and didn t realize that
          Message 4 of 8 , Jul 6, 2013
          • 0 Attachment
            Kevin,

            Many thanks. From your earlier message I assumed that you had more information about the Xtal set builders at hand than you did, and didn't realize that you would need to do a search to answer my request. This dumb-A could have done that. I appreciate your effort,and sorry for the trouble. The links are a great starting point.

            Tom
            K4ZAD

            *********************************************

            --- In loopantennas@yahoogroups.com, kevin asato <kc6pob@...> wrote:
            >
            > As requested. Not trying to be a smart-A but these are two that popped up readily.
            >
            > http://antiquewireless.org/otb/dxxtal.htm
            > http://members.shaw.ca/ve7sl/crystal.html
            >
            >
            > If you notice the coil construction, there are a couple of techniques being used. One is a basketweave type construction and the other is the normal spiral wrap on a coil form. By not having the coils fixed in place as in the Twin Coil design, you can adjust the coupling between the coils to peak what you are trying to listen to. I suppose you could manage to alter the distance between coils on the Twin Coil design but then you would not be able to use the weather proof case for remote mounting! I suppose you can probably come up with similar results using separate loopstick antenna coils.
            >
            >
            > Makearadio.com has instructions on winding basketweave antenna coils, larger frame type coils, and spider coils.
            >
            > 73,
            > kevin
            > kc6pob
            >
            >
            > ________________________________
            > From: tmckee_k4zad <mckeetajc@...>
            > To: loopantennas@yahoogroups.com
            > Sent: Friday, July 5, 2013 7:41 AM
            > Subject: [loopantennas] Re: c-crane dual coil antenna?
            >
            >
            >
            >  
            > Kevin,
            >
            > I would much appreciate it if you would supply links to a site or two where one can learn more about Xtal set builders use of multiple air-wound coils in the same plane.
            >
            > Thanks,
            >
            > Tom
            > K4ZAD
          • kevin asato
            No Problem! With work being so busy, things have been falling out of the bit bucket so I have had tendency lately to just refer to things off the web (with a
            Message 5 of 8 , Jul 6, 2013
            • 0 Attachment
              No Problem!
              With work being so busy, things have been falling out of the bit bucket so I have had tendency lately to just refer to things off the web (with a reasonable sanity check). Saves on "now what file did I put that under ??" ! Those are a couple of sites, with included links that I refer to when trying to look up crystal sets and I don't mind sharing. I am going through those again as I am researching antenna coils to use for building a Tuned Radio Frequency (TRF) radio. I found a ZN414 TRF IC and trying to figure how I want to build the "front end" without buying a ferrite loopstick antenna. There are inherent weaknesses in the radio and chipset design and i also have to worry about a 50KW flamethrower 3 air miles away from me. The links also show how to build bandstop filters which will help attenuate, but not eliminate, the strong AM station (KNX-1070KHz).
              73,
              kevin
              kc6pob

              From: tmckee_k4zad <mckeetajc@...>
              To: loopantennas@yahoogroups.com
              Sent: Saturday, July 6, 2013 6:01 AM
              Subject: [loopantennas] Re: c-crane dual coil antenna?

               
              Kevin,

              Many thanks. From your earlier message I assumed that you had more information about the Xtal set builders at hand than you did, and didn't realize that you would need to do a search to answer my request. This dumb-A could have done that. I appreciate your effort,and sorry for the trouble. The links are a great starting point.

              Tom
              K4ZAD

              *********************************************

              --- In loopantennas@yahoogroups.com, kevin asato <kc6pob@...> wrote:
              >
              > As requested. Not trying to be a smart-A but these are two that popped up readily.
              >
              > http://antiquewireless.org/otb/dxxtal.htm
              > http://members.shaw.ca/ve7sl/crystal.html
              >
              >
              > If you notice the coil construction, there are a couple of techniques being used. One is a basketweave type construction and the other is the normal spiral wrap on a coil form. By not having the coils fixed in place as in the Twin Coil design, you can adjust the coupling between the coils to peak what you are trying to listen to. I suppose you could manage to alter the distance between coils on the Twin Coil design but then you would not be able to use the weather proof case for remote mounting! I suppose you can probably come up with similar results using separate loopstick antenna coils.
              >
              >
              > Makearadio.com has instructions on winding basketweave antenna coils, larger frame type coils, and spider coils.
              >
              > 73,
              > kevin
              > kc6pob
              >
              >
              > ________________________________
              > From: tmckee_k4zad <mckeetajc@...>
              > To: loopantennas@yahoogroups.com
              > Sent: Friday, July 5, 2013 7:41 AM
              > Subject: [loopantennas] Re: c-crane dual coil antenna?
              >
              >
              >
              >  
              > Kevin,
              >
              > I would much appreciate it if you would supply links to a site or two where one can learn more about Xtal set builders use of multiple air-wound coils in the same plane.
              >
              > Thanks,
              >
              > Tom
              > K4ZAD



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