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Multiwire cable tip

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  • Jim Garland
    Most SP builders use commercial 25pin serial cables to interface their SP controller to their transceivers. A few builders, however, who have been troubled
    Message 1 of 6 , Apr 7, 2013

      Most SP builders use commercial 25pin serial cables to interface their SP controller to their transceivers. A few builders, however, who have been troubled with computer crosstalk make their own cables (instructions can be downloaded from the SP website), which can be made with more isolation between the wires. I just discovered a source of high-quality multi wire cable, when I salvaged the cable from an old Hewlett-Packard HPIB cable.  These cables (with attached connectors) were several hundred dollars new, but can be picked up on eBay in various lengths at a fraction of the original cost, typically $15-$20. The cables are 24 conductors of high quality 24 AWG (I think) individually color-coded wire. There is an inner cluster of 8 wires, with double aluminum foil shields around the cluster, surrounded by the outer 16 wires. The whole bundle has an aluminum foil shield, which is surrounded by a silver-plated copper braid. It’s very high quality multiwire cable, the nicest I’ve seen, and ought to provide the ultimate in isolation and RF shielding. The inner cluster of 8 wires is perfect for microphone wiring between the SP controller and the transceiver pods.

      73,

      Jim W8ZR

    • Torrey Mitchell
      Jim, Can you share what search terms we can use on Ebay to locate these cables. Thanks! Torrey N9PY ... Jim, Can you share what search terms we can use on Ebay
      Message 2 of 6 , Apr 7, 2013
        Jim,

        Can you share what search terms we can use on Ebay to locate these cables.

        Thanks!

        Torrey N9PY

        On Apr 7, 2013, at 4:08 PM, "Jim Garland" <4cx250b@...> wrote:

         

        Most SP builders use commercial 25pin serial cables to interface their SP controller to their transceivers. A few builders, however, who have been troubled with computer crosstalk make their own cables (instructions can be downloaded from the SP website), which can be made with more isolation between the wires. I just discovered a source of high-quality multi wire cable, when I salvaged the cable from an old Hewlett-Packard HPIB cable.  These cables (with attached connectors) were several hundred dollars new, but can be picked up on eBay in various lengths at a fraction of the original cost, typically $15-$20. The cables are 24 conductors of high quality 24 AWG (I think) individually color-coded wire. There is an inner cluster of 8 wires, with double aluminum foil shields around the cluster, surrounded by the outer 16 wires. The whole bundle has an aluminum foil shield, which is surrounded by a silver-plated copper braid. It’s very high quality multiwire cable, the nicest I’ve seen, and ought to provide the ultimate in isolation and RF shielding. The inner cluster of 8 wires is perfect for microphone wiring between the SP controller and the transceiver pods.

        73,

        Jim W8ZR

      • Thomas Schaefer
        I searched for this: hpib cable -new I found mostly 1 meter cables in the $20 range but there was one 6 feet long for $13.
        Message 3 of 6 , Apr 7, 2013
          I searched for this: hpib cable -new

          I found mostly 1 meter cables in the $20 range but there was one 6 feet long for $13.


          Is this the type cable to which you refer Jim?

          Thanks,

          Tom NY4I

          727-437-2771



          On Apr 7, 2013, at 8:16 PM, Torrey Mitchell <torreym@...> wrote:

           

          Jim,

          Can you share what search terms we can use on Ebay to locate these cables.

          Thanks!

          Torrey N9PY

          On Apr 7, 2013, at 4:08 PM, "Jim Garland" <4cx250b@...> wrote:

           

          Most SP builders use commercial 25pin serial cables to interface their SP controller to their transceivers. A few builders, however, who have been troubled with computer crosstalk make their own cables (instructions can be downloaded from the SP website), which can be made with more isolation between the wires. I just discovered a source of high-quality multi wire cable, when I salvaged the cable from an old Hewlett-Packard HPIB cable.  These cables (with attached connectors) were several hundred dollars new, but can be picked up on eBay in various lengths at a fraction of the original cost, typically $15-$20. The cables are 24 conductors of high quality 24 AWG (I think) individually color-coded wire. There is an inner cluster of 8 wires, with double aluminum foil shields around the cluster, surrounded by the outer 16 wires. The whole bundle has an aluminum foil shield, which is surrounded by a silver-plated copper braid. It’s very high quality multiwire cable, the nicest I’ve seen, and ought to provide the ultimate in isolation and RF shielding. The inner cluster of 8 wires is perfect for microphone wiring between the SP controller and the transceiver pods.

          73,

          Jim W8ZR




        • MU 4CX250B
          Hi Tom, Yes, that s it. Most of the cables are about 6 ft (2m) long, which is perfect for an SP interconnect, but they is also available in longer lengths.
          Message 4 of 6 , Apr 7, 2013
            Hi Tom,
            Yes, that's it.  Most of the cables are about 6 ft (2m) long, which is perfect for an SP interconnect, but they is also available in longer lengths. You can search on HPIB, GPIB, and IEEE-488 cable. FYI, HP invented what became known as the IEEE 488 interface bus, which was a means to network lab instrumentation. The HP implementation was called the HPIB standard, but everybody else called it the General Purpose Interface Bus (GPIB). Cables are made by other manufacturers and may be equally high quality, but the one I scavenged was an HP cable. BTW it wil break your heart to clip off the connectors, which are a work of art. Alas, technology marches on.
            73,
            Jim

            Sent from my iPad

            On Apr 7, 2013, at 18:40, Thomas Schaefer <ny4i@...> wrote:

             

            I searched for this: hpib cable -new


            I found mostly 1 meter cables in the $20 range but there was one 6 feet long for $13.


            Is this the type cable to which you refer Jim?

            Thanks,

            Tom NY4I

            727-437-2771



            On Apr 7, 2013, at 8:16 PM, Torrey Mitchell <torreym@...> wrote:

             

            Jim,

            Can you share what search terms we can use on Ebay to locate these cables.

            Thanks!

            Torrey N9PY

            On Apr 7, 2013, at 4:08 PM, "Jim Garland" <4cx250b@...> wrote:

             

            Most SP builders use commercial 25pin serial cables to interface their SP controller to their transceivers. A few builders, however, who have been troubled with computer crosstalk make their own cables (instructions can be downloaded from the SP website), which can be made with more isolation between the wires. I just discovered a source of high-quality multi wire cable, when I salvaged the cable from an old Hewlett-Packard HPIB cable.  These cables (with attached connectors) were several hundred dollars new, but can be picked up on eBay in various lengths at a fraction of the original cost, typically $15-$20. The cables are 24 conductors of high quality 24 AWG (I think) individually color-coded wire. There is an inner cluster of 8 wires, with double aluminum foil shields around the cluster, surrounded by the outer 16 wires. The whole bundle has an aluminum foil shield, which is surrounded by a silver-plated copper braid. It’s very high quality multiwire cable, the nicest I’ve seen, and ought to provide the ultimate in isolation and RF shielding. The inner cluster of 8 wires is perfect for microphone wiring between the SP controller and the transceiver pods.

            73,

            Jim W8ZR




          • Paul Christensen
            Jim, This looks like really nice cable. Never heard of it before. So far, the standard DB cables have been working well here, but if crosstalk were to become
            Message 5 of 6 , Apr 7, 2013
              Jim,
               
              This looks like really nice cable.  Never heard of it before.  So far, the standard DB cables have been working well here, but if crosstalk were to become an issue, I've given thought to using between two and three pairs of shielded CAT 5E/6 cabling.  That places 8 conductors of hyper-twisted pairs into a shielded cable.  For current use with my transceivers, likely two CAT 6 pairs will be fine. 
               
              The hyper-twisting of conductor pairs often results in greater crosstalk reduction than shielding alone -- and one of the reasons for the Ethernet cabling standards.   The source and destination impedance of the cabling also has a profound effect on crosstalk.  For example, a conductor pair terminated into a Hi-Z is generally more prone to crosstalk than that of low-Z terminations.  Really, it's just an adaptation of the decades-old Telco standards where source and destination Z are minimized while twisting conductors to mitigate crosstalk.  Dropping the source Z also results in better frequency response over long, capacitive cable runs. 
               
              If crosstalk became a problem with the SP when using say...a D104 crystal element into the Hi-Z mic input of an old boatanchor transmitter, I would be tempted to try Ethernet cabling in conjunction with the lowering of the mic source Z as well as the mic input circuit.  That's a case where a JFET as a source-follower really shines when mounted into the mic base.
               
              Anyone here tried Ethernet cabling between their Station Pros and Pods?
               
              Paul, W9AC     
               
              ----- Original Message -----
              Sent: Sunday, April 07, 2013 9:21 PM
              Subject: Re: [stationpro] Multiwire cable tip

               

              Hi Tom,
              Yes, that's it.  Most of the cables are about 6 ft (2m) long, which is perfect for an SP interconnect, but they is also available in longer lengths. You can search on HPIB, GPIB, and IEEE-488 cable. FYI, HP invented what became known as the IEEE 488 interface bus, which was a means to network lab instrumentation. The HP implementation was called the HPIB standard, but everybody else called it the General Purpose Interface Bus (GPIB). Cables are made by other manufacturers and may be equally high quality, but the one I scavenged was an HP cable. BTW it wil break your heart to clip off the connectors, which are a work of art. Alas, technology marches on.
              73,
              Jim

              Sent from my iPad

              On Apr 7, 2013, at 18:40, Thomas Schaefer <ny4i@...> wrote:

               

              I searched for this: hpib cable -new


              I found mostly 1 meter cables in the $20 range but there was one 6 feet long for $13.


              Is this the type cable to which you refer Jim?

              Thanks,

              Tom NY4I

              727-437-2771



              On Apr 7, 2013, at 8:16 PM, Torrey Mitchell <torreym@...> wrote:

               

              Jim,

              Can you share what search terms we can use on Ebay to locate these cables.

              Thanks!

              Torrey N9PY

              On Apr 7, 2013, at 4:08 PM, "Jim Garland" <4cx250b@...> wrote:

               

              Most SP builders use commercial 25pin serial cables to interface their SP controller to their transceivers. A few builders, however, who have been troubled with computer crosstalk make their own cables (instructions can be downloaded from the SP website), which can be made with more isolation between the wires. I just discovered a source of high-quality multi wire cable, when I salvaged the cable from an old Hewlett-Packard HPIB cable.  These cables (with attached connectors) were several hundred dollars new, but can be picked up on eBay in various lengths at a fraction of the original cost, typically $15-$20. The cables are 24 conductors of high quality 24 AWG (I think) individually color-coded wire. There is an inner cluster of 8 wires, with double aluminum foil shields around the cluster, surrounded by the outer 16 wires. The whole bundle has an aluminum foil shield, which is surrounded by a silver-plated copper braid. It’s very high quality multiwire cable, the nicest I’ve seen, and ought to provide the ultimate in isolation and RF shielding. The inner cluster of 8 wires is perfect for microphone wiring between the SP controller and the transceiver pods.

              73,

              Jim W8ZR




            • MU 4CX250B
              Interesting comments, Paul. As I recall, the four twisted pairs in CAT5 or CAT6 cable each have 100 ohms impedance, but I don t know what the capacitance/ft
              Message 6 of 6 , Apr 7, 2013
                Interesting comments, Paul. As I recall, the four twisted pairs in CAT5 or CAT6 cable each have 100 ohms impedance, but I don't know what the capacitance/ft is. If it's too high that may cause a problem with high-Z mics. Also, I wonder if there might be a problem attaching twenty-four 26 AWG solid wires to DB25 connectors. Ideally, I'd think heavier gauge stranded wire would be more reliable and flexible, but I've not tried CAT6 cable. It might work just fine.
                73,
                Jim W8ZR

                Sent from my iPad

                On Apr 7, 2013, at 19:52, Paul Christensen <w9ac@...> wrote:

                 

                Jim,
                 
                This looks like really nice cable.  Never heard of it before.  So far, the standard DB cables have been working well here, but if crosstalk were to become an issue, I've given thought to using between two and three pairs of shielded CAT 5E/6 cabling.  That places 8 conductors of hyper-twisted pairs into a shielded cable.  For current use with my transceivers, likely two CAT 6 pairs will be fine. 
                 
                The hyper-twisting of conductor pairs often results in greater crosstalk reduction than shielding alone -- and one of the reasons for the Ethernet cabling standards.   The source and destination impedance of the cabling also has a profound effect on crosstalk.  For example, a conductor pair terminated into a Hi-Z is generally more prone to crosstalk than that of low-Z terminations.  Really, it's just an adaptation of the decades-old Telco standards where source and destination Z are minimized while twisting conductors to mitigate crosstalk.  Dropping the source Z also results in better frequency response over long, capacitive cable runs. 
                 
                If crosstalk became a problem with the SP when using say...a D104 crystal element into the Hi-Z mic input of an old boatanchor transmitter, I would be tempted to try Ethernet cabling in conjunction with the lowering of the mic source Z as well as the mic input circuit.  That's a case where a JFET as a source-follower really shines when mounted into the mic base.
                 
                Anyone here tried Ethernet cabling between their Station Pros and Pods?
                 
                Paul, W9AC     
                 
                ----- Original Message -----
                Sent: Sunday, April 07, 2013 9:21 PM
                Subject: Re: [stationpro] Multiwire cable tip

                 

                Hi Tom,
                Yes, that's it.  Most of the cables are about 6 ft (2m) long, which is perfect for an SP interconnect, but they is also available in longer lengths. You can search on HPIB, GPIB, and IEEE-488 cable. FYI, HP invented what became known as the IEEE 488 interface bus, which was a means to network lab instrumentation. The HP implementation was called the HPIB standard, but everybody else called it the General Purpose Interface Bus (GPIB). Cables are made by other manufacturers and may be equally high quality, but the one I scavenged was an HP cable. BTW it wil break your heart to clip off the connectors, which are a work of art. Alas, technology marches on.
                73,
                Jim

                Sent from my iPad

                On Apr 7, 2013, at 18:40, Thomas Schaefer <ny4i@...> wrote:

                 

                I searched for this: hpib cable -new


                I found mostly 1 meter cables in the $20 range but there was one 6 feet long for $13.


                Is this the type cable to which you refer Jim?

                Thanks,

                Tom NY4I

                727-437-2771



                On Apr 7, 2013, at 8:16 PM, Torrey Mitchell <torreym@...> wrote:

                 

                Jim,

                Can you share what search terms we can use on Ebay to locate these cables.

                Thanks!

                Torrey N9PY

                On Apr 7, 2013, at 4:08 PM, "Jim Garland" <4cx250b@...> wrote:

                 

                Most SP builders use commercial 25pin serial cables to interface their SP controller to their transceivers. A few builders, however, who have been troubled with computer crosstalk make their own cables (instructions can be downloaded from the SP website), which can be made with more isolation between the wires. I just discovered a source of high-quality multi wire cable, when I salvaged the cable from an old Hewlett-Packard HPIB cable.  These cables (with attached connectors) were several hundred dollars new, but can be picked up on eBay in various lengths at a fraction of the original cost, typically $15-$20. The cables are 24 conductors of high quality 24 AWG (I think) individually color-coded wire. There is an inner cluster of 8 wires, with double aluminum foil shields around the cluster, surrounded by the outer 16 wires. The whole bundle has an aluminum foil shield, which is surrounded by a silver-plated copper braid. It’s very high quality multiwire cable, the nicest I’ve seen, and ought to provide the ultimate in isolation and RF shielding. The inner cluster of 8 wires is perfect for microphone wiring between the SP controller and the transceiver pods.

                73,

                Jim W8ZR




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