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Re: [softrock40] Softrock RXTX Ensemble with a Magnetic Loop Antenna

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  • Sid Boyce
    That should have read 3/8 diameter soft copper. 73 ... Sid. ... -- Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot Emeritus IBM/Amdahl Mainframes
    Message 1 of 10 , Apr 1, 2011
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      That should have read 3/8" diameter soft copper.
      73 ... Sid.

      On 01/04/11 12:19, Sid Boyce wrote:
      > Whilst not Ensemble specific, I have used magnetic loops for many years.
      > The first one was a 1m diameter 3/8" soft copper loop tuned with a
      > standard capacitor that was only capable of handling the RF voltage at
      > 7W. With that loop indoors I worked all over Europe with excellent reports.
      >
      > My next loop was 28mm copper tube with 45 degree elbows (13' diameter)
      > tuned with a vacuum capacitor that accounted for all my 80m Stateside
      > contacts running 100W. Sadly it got smashed, vacuum capacitor and all in
      > 60+ MPH high winds but I'm hoping to put it together again with better
      > support.
      >
      > The current loop for 80m/40m is made from 22mm copper tube with 45
      > degree elbows (8' in diameter) with the vacuum capacitor mounted at the
      > bottom in a 4" diameter PVC tube, ends filled with foam, done so as to
      > lower the wind resistance. Currently using it with a SR v6.3 + Mobo v3.6
      > for wspr.
      > I haven't seen anyone spotting me so far, but I'm receiving all over
      > Europe on 80m/40m/20m and a number of USA stations on 20m. I have
      > successfully used it on TX with my IC-7200 on 40m SSB running 100W.
      >
      > I've found my loops work best with Gamma matching, I never seem to get
      > good matching with the faraday loop across all covered bands.
      >
      > The outdoor loops use remote tuning, a 12V motor from maplin.co.uk with
      > an insulated coupler to the vacuum capacitor controlled by a LM317 motor
      > controller in the shack, a DPDT switch for changing motor direction. SWR
      > measured for the desired frequency with a MFJ-259B.
      >
      > I have another 40m loop in the garage that's yet to be tested outdoors,
      > it uses a home brewed copper butterfly capacitor, tuning was difficult
      > when I tried it indoors perhaps due to the threaded shafts being
      > magnetic, so I plan to solder copper strip across all the plates. The
      > capacitor is wide-spaced calculated to take 100W.
      >
      > I'll pass on the advice given to me on the air when I joined a
      > discussion on magnetic loops - build one. Two days later and an hour's
      > work and I was working all over Europe with 7W.
      > 73 ... Sid.
      >
      >
      > On 01/04/11 11:14, Dan wrote:
      >> Hi,
      >>
      >> Anyone on this list with some success stories about using a magnetic
      >> loop antenna with a Softrock RXTX Ensemble?
      >>
      >> If yes, can he provide some details about the setup and the results?
      >> Considering the very high Q of a magnetic loop, the supplemental LPF is
      >> still required for the lower bands of the specific RXTX model (ex. 80.40
      >> for 40-30-20 RXTX Ensemble model)?
      >>
      >> --
      >> 73
      >> Dan
      >> YO3GGX
      >> WebSDR http://yo3ggx.1p.ro
      >>
      >>
      >
      >


      --
      Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
      Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
      Specialist, Cricket Coach
      Microsoft Windows Free Zone - Linux used for all Computing Tasks
    • Dan
      Hi Sid, Very encouraging your mail. Tomorrow I ll go shopping for the parts ...:-) I have two RXTX Ensembles (40-30-20) and (15-12-10) which I intend to
      Message 2 of 10 , Apr 1, 2011
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        Hi Sid,

        Very encouraging your mail.
        Tomorrow I'll go shopping for the parts ...:-)
        I have two RXTX Ensembles (40-30-20) and (15-12-10) which I intend to
        dedicate to WSPR using 2 magnetic loops.

        --
        73
        Dan
        YO3GGX
        WebSDR http://yo3ggx.1p.ro


        On 4/1/2011 2:19 PM, Sid Boyce wrote:
        > Whilst not Ensemble specific, I have used magnetic loops for many years.
        > The first one was a 1m diameter 3/" soft copper loop tuned with a
        > standard capacitor that was only capable of handling the RF voltage at
        > 7W. With that loop indoors I worked all over Europe with excellent reports.
        >
        > My next loop was 28mm copper tube with 45 degree elbows (13' diameter)
        > tuned with a vacuum capacitor that accounted for all my 80m Stateside
        > contacts running 100W. Sadly it got smashed, vacuum capacitor and all in
        > 60+ MPH high winds but I'm hoping to put it together again with better
        > support.
        >
        > The current loop for 80m/40m is made from 22mm copper tube with 45
        > degree elbows (8' in diameter) with the vacuum capacitor mounted at the
        > bottom in a 4" diameter PVC tube, ends filled with foam, done so as to
        > lower the wind resistance. Currently using it with a SR v6.3 + Mobo v3.6
        > for wspr.
        > I haven't seen anyone spotting me so far, but I'm receiving all over
        > Europe on 80m/40m/20m and a number of USA stations on 20m. I have
        > successfully used it on TX with my IC-7200 on 40m SSB running 100W.
        >
        > I've found my loops work best with Gamma matching, I never seem to get
        > good matching with the faraday loop across all covered bands.
        >
        > The outdoor loops use remote tuning, a 12V motor from maplin.co.uk with
        > an insulated coupler to the vacuum capacitor controlled by a LM317 motor
        > controller in the shack, a DPDT switch for changing motor direction. SWR
        > measured for the desired frequency with a MFJ-259B.
        >
        > I have another 40m loop in the garage that's yet to be tested outdoors,
        > it uses a home brewed copper butterfly capacitor, tuning was difficult
        > when I tried it indoors perhaps due to the threaded shafts being
        > magnetic, so I plan to solder copper strip across all the plates. The
        > capacitor is wide-spaced calculated to take 100W.
        >
        > I'll pass on the advice given to me on the air when I joined a
        > discussion on magnetic loops - build one. Two days later and an hour's
        > work and I was working all over Europe with 7W.
        > 73 ... Sid.
        >
        >
        > On 01/04/11 11:14, Dan wrote:
        >> Hi,
        >>
        >> Anyone on this list with some success stories about using a magnetic
        >> loop antenna with a Softrock RXTX Ensemble?
        >>
        >> If yes, can he provide some details about the setup and the results?
        >> Considering the very high Q of a magnetic loop, the supplemental LPF is
        >> still required for the lower bands of the specific RXTX model (ex. 80.40
        >> for 40-30-20 RXTX Ensemble model)?
        >>
        >> --
        >
      • Oliver Goldenstein
        Hi Dan ! Dan my answer was a bit short, because i was on mobile. We have the 1st of April. This was not a joke with the can Antenna. This little thing works
        Message 3 of 10 , Apr 1, 2011
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          Hi Dan !

          Dan my answer was a bit short, because i was on mobile.

          We have the 1st of April. This was not a joke with the can Antenna.
          This little thing works great and you have much fewer noise, when u
          have the chance to put this little thing outside?

          I guess you will have everything at home for it.

          Good luck, Oliver, DL6KBG

          On 1 April 2011 14:11, Dan <danto@...> wrote:
          > Hi Sid,
          >
          > Very encouraging your mail.
          > Tomorrow I'll go shopping for the parts ...:-)
          > I have two RXTX Ensembles (40-30-20) and (15-12-10) which I intend to
          > dedicate to WSPR using 2 magnetic loops.
          >
          > --
          > 73
          > Dan
          > YO3GGX
          > WebSDR http://yo3ggx.1p.ro
          >
          >
          > On 4/1/2011 2:19 PM, Sid Boyce wrote:
          >> Whilst not Ensemble specific, I have used magnetic loops for many years.
          >> The first one was a 1m diameter 3/" soft copper loop tuned with a
          >> standard capacitor that was only capable of handling the RF voltage at
          >> 7W. With that loop indoors I worked all over Europe with excellent reports.
          >>
          >> My next loop was 28mm copper tube with 45 degree elbows (13' diameter)
          >> tuned with a vacuum capacitor that accounted for all my 80m Stateside
          >> contacts running 100W. Sadly it got smashed, vacuum capacitor and all in
          >> 60+ MPH high winds but I'm hoping to put it together again with better
          >> support.
          >>
          >> The current loop for 80m/40m is made from 22mm copper tube with 45
          >> degree elbows (8' in diameter) with the vacuum capacitor mounted at the
          >> bottom in a 4" diameter PVC tube, ends filled with foam, done so as to
          >> lower the wind resistance. Currently using it with a SR v6.3 + Mobo v3.6
          >> for wspr.
          >> I haven't seen anyone spotting me so far, but I'm receiving all over
          >> Europe on 80m/40m/20m and a number of USA stations on 20m. I have
          >> successfully used it on TX with my IC-7200 on 40m SSB running 100W.
          >>
          >> I've found my loops work best with Gamma matching, I never seem to get
          >> good matching with the faraday loop across all covered bands.
          >>
          >> The outdoor loops use remote tuning, a 12V motor from maplin.co.uk with
          >> an insulated coupler to the vacuum capacitor controlled by a LM317 motor
          >> controller in the shack, a DPDT switch for changing motor direction. SWR
          >> measured for the desired frequency with a MFJ-259B.
          >>
          >> I have another 40m loop in the garage that's yet to be tested outdoors,
          >> it uses a home brewed copper butterfly capacitor, tuning was difficult
          >> when I tried it indoors perhaps due to the threaded shafts being
          >> magnetic, so I plan to solder copper strip across all the plates. The
          >> capacitor is wide-spaced calculated to take 100W.
          >>
          >> I'll pass on the advice given to me on the air when I joined a
          >> discussion on magnetic loops - build one. Two days later and an hour's
          >> work and I was working all over Europe with 7W.
          >> 73 ... Sid.
          >>
          >>
          >> On 01/04/11 11:14, Dan wrote:
          >>> Hi,
          >>>
          >>> Anyone on this list with some success stories about using a magnetic
          >>> loop antenna with a Softrock RXTX Ensemble?
          >>>
          >>> If yes, can he provide some details about the setup and the results?
          >>> Considering the very high Q of a magnetic loop, the supplemental LPF is
          >>> still required for the lower bands of the specific RXTX model (ex. 80.40
          >>> for 40-30-20 RXTX Ensemble model)?
          >>>
          >>> --
          >>
          >
          >
          >
          > ------------------------------------
          >
          > Yahoo! Groups Links
          >
          >
          >
          >



          --
          Oliver, DL6KBG, JO61UB
          Blog: http://dl6kbg.blogspot.com
        • Sid Boyce
          They work quite well. I even heard one guy say that when his beam blew down he used one and was able to maintain his daily sked UK to ZL. One other positive
          Message 4 of 10 , Apr 1, 2011
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            They work quite well. I even heard one guy say that when his beam blew
            down he used one and was able to maintain his daily sked UK to ZL.

            One other positive is that they don't need the height. Tony (G4OGP) who
            first sold magnetic loops in the UK said that he had used one on top of
            Blackpool tower and at ground level with no difference in performance.

            Usually at the then Leicester show which was in a large steel hangar,
            all the vendors could only show you their gear and say that antennas
            couldn't work at that location, while Tony had one of his loops on the
            air, pulling in European stations at 59+ and making QSO's.

            It was much much later before MFJ produced their magnetic loop.

            They are a number of Windows and DOS calculator programs on the net,
            mloop, mloop31, etc. so you can play with different parameters ahead of
            ordering any hardware. Also if anyone is interested in playing with
            different sizes and shapes of magnetic loops, these programs give you a
            good idea. I start off with inputting different sizes of copper, tubing
            lengths and shapes and when I come up with something that I like, I buy
            the materials and put it together.
            I use a Gamma match for lowest SWR, usually close to 1:1 and fire it up.

            Though copper is best, Tony's loops were made from aluminium tube, his
            customers were not only hams but Embassies and other government
            agencies. I've seen some made of aluminium curtain track.
            73 ... Sid.

            On 01/04/11 13:11, Dan wrote:
            > Hi Sid,
            >
            > Very encouraging your mail.
            > Tomorrow I'll go shopping for the parts ...:-)
            > I have two RXTX Ensembles (40-30-20) and (15-12-10) which I intend to
            > dedicate to WSPR using 2 magnetic loops.
            >


            --
            Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
            Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
            Specialist, Cricket Coach
            Microsoft Windows Free Zone - Linux used for all Computing Tasks
          • Richard
            ... You can also make them out of expensive heliax cable such as LDF4-50, once water gets in it its pretty usless and gets thrown away. But you only use the
            Message 5 of 10 , Apr 1, 2011
            • 0 Attachment
              On Fri, 2011-04-01 at 20:09 +0100, Sid Boyce wrote:
              >
              > They work quite well. I even heard one guy say that when his beam
              > blew
              > down he used one and was able to maintain his daily sked UK to ZL.
              >
              > One other positive is that they don't need the height. Tony (G4OGP)
              > who
              > first sold magnetic loops in the UK said that he had used one on top
              > of
              > Blackpool tower and at ground level with no difference in performance.
              >
              > Usually at the then Leicester show which was in a large steel hangar,
              > all the vendors could only show you their gear and say that antennas
              > couldn't work at that location, while Tony had one of his loops on
              > the
              > air, pulling in European stations at 59+ and making QSO's.
              >
              > It was much much later before MFJ produced their magnetic loop.
              >
              > They are a number of Windows and DOS calculator programs on the net,
              > mloop, mloop31, etc. so you can play with different parameters ahead
              > of
              > ordering any hardware. Also if anyone is interested in playing with
              > different sizes and shapes of magnetic loops, these programs give you
              > a
              > good idea. I start off with inputting different sizes of copper,
              > tubing
              > lengths and shapes and when I come up with something that I like, I
              > buy
              > the materials and put it together.
              > I use a Gamma match for lowest SWR, usually close to 1:1 and fire it
              > up.
              >
              > Though copper is best, Tony's loops were made from aluminium tube,
              > his
              > customers were not only hams but Embassies and other government
              > agencies. I've seen some made of aluminium curtain track.
              > 73 ... Sid.
              You can also make them out of expensive heliax cable such as LDF4-50,
              once water gets in it its pretty usless and gets thrown away.
              But you only use the outside solid ( corrugated ), copper and its self
              supporting within reason, AND its an interference fit to 15 mm Cu
              tubing, 1/2" will be very close as well.
              I've a 6 mtr diameter loop in the garden I use on 160 & 80 Mtrs.
              Two wood cross members and the whole thing is on a fibreglass pole.

              I'd be interested in how broadband your gamma match is Sid ?
              I use a loop and its gone a bit higher than normal.

              --
              Best wishes / 73
              Richard Bown

              E-mail: richard@...

              nil carborundum a illegitemis
              ########################################################################
              Sent by Evolution 2.32.1 on Fedora FC14 x86_64 Dual core AMD Athlon 4400
              Ham Call:G8JVM
              Maidenhead QRA: IO82SP38:LAT. 52 39.720':N LONG. 2 28.171 W (degs,mins )
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            • Sid Boyce
              The bandwidth is around 2.7 KHz for the loop made of 22mm copper tube. 73 ... Sid. ... -- Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot Emeritus
              Message 6 of 10 , Apr 1, 2011
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                The bandwidth is around 2.7 KHz for the loop made of 22mm copper tube.
                73 ... Sid.

                On 01/04/11 20:43, Richard wrote:
                > On Fri, 2011-04-01 at 20:09 +0100, Sid Boyce wrote:
                >>
                >> They work quite well. I even heard one guy say that when his beam
                >> blew
                >> down he used one and was able to maintain his daily sked UK to ZL.
                >>
                >> One other positive is that they don't need the height. Tony (G4OGP)
                >> who
                >> first sold magnetic loops in the UK said that he had used one on top
                >> of
                >> Blackpool tower and at ground level with no difference in performance.
                >>
                >> Usually at the then Leicester show which was in a large steel hangar,
                >> all the vendors could only show you their gear and say that antennas
                >> couldn't work at that location, while Tony had one of his loops on
                >> the
                >> air, pulling in European stations at 59+ and making QSO's.
                >>
                >> It was much much later before MFJ produced their magnetic loop.
                >>
                >> They are a number of Windows and DOS calculator programs on the net,
                >> mloop, mloop31, etc. so you can play with different parameters ahead
                >> of
                >> ordering any hardware. Also if anyone is interested in playing with
                >> different sizes and shapes of magnetic loops, these programs give you
                >> a
                >> good idea. I start off with inputting different sizes of copper,
                >> tubing
                >> lengths and shapes and when I come up with something that I like, I
                >> buy
                >> the materials and put it together.
                >> I use a Gamma match for lowest SWR, usually close to 1:1 and fire it
                >> up.
                >>
                >> Though copper is best, Tony's loops were made from aluminium tube,
                >> his
                >> customers were not only hams but Embassies and other government
                >> agencies. I've seen some made of aluminium curtain track.
                >> 73 ... Sid.
                > You can also make them out of expensive heliax cable such as LDF4-50,
                > once water gets in it its pretty usless and gets thrown away.
                > But you only use the outside solid ( corrugated ), copper and its self
                > supporting within reason, AND its an interference fit to 15 mm Cu
                > tubing, 1/2" will be very close as well.
                > I've a 6 mtr diameter loop in the garden I use on 160& 80 Mtrs.
                > Two wood cross members and the whole thing is on a fibreglass pole.
                >
                > I'd be interested in how broadband your gamma match is Sid ?
                > I use a loop and its gone a bit higher than normal.
                >


                --
                Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot
                Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support
                Specialist, Cricket Coach
                Microsoft Windows Free Zone - Linux used for all Computing Tasks
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