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How do I repair this strange pup made in Italy

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  • How do I repair this strange pup made in Italy

    I was given a dead pickup to repair. It comes out of a 60” two pickup guitar. The owner says that this is a one-of-a-kind with a matching amplifier. The winding was epoxied/glued in the chrome cover but I managed to separate and remove the frame and winding (see picture)
    Has anyone ever seen one like this and what would the best approach be to repair
    Any help would be appreciated
    Thanks
    Norm
    Click image for larger version

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  • #2
    The photos are too small and too blurry to tell. A few more views may be helpful too.

    Comment


    • #3
      It looks like a bobbin-less coil. You would have to wind a new coil. You will have to devise how to do that.

      Joe, you clicked on the pictures? They open very large, though they are blurry. Norm, you need to use the macro setting on the camera for extreme close ups.
      It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein


      http://coneyislandguitars.com
      www.soundcloud.com/davidravenmoon

      Comment


      • #4
        Originally posted by David Schwab View Post
        Joe, you clicked on the pictures? They open very large, though they are blurry.
        I did click on them.

        Norm, you need to use the macro setting on the camera for extreme close ups.
        Also, the camera needs far more light so it can achieve sufficient depth of field.

        Comment


        • #5
          Sorry guys, I didn't get a chance to respond right away. I took more pictures, hope they’re better. I dropped my camera a while back and it doesn’t seem to focus like it used to.
          The winding is like a separate bundle of rope……..there are 4 what looks like ceramic discs that are riveted between a top and bottom plate and the pre wound winding is placed around the mags.
          I think I need to make a dummy bobbin with a removable top cover, line it with a few pieces of tape (to hold it together before I slide it out); then carefully wrap the winding wad with tape and slip it over the mags…..
          Norm
          Attached Files

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          • #6
            Are the top and bottom plates magnetically conductive? From your description of the internal construction, I'm guessing that the retaining rivets passing through the magnets are, but not the top and bottom plates.

            Does one need to wind the coil independently, and then place it over the magnet structure like a preformed hoop? I'm no expert, but personally I don't think so. My sense is this was just a manufacturing convenience. As long as the structure they are placed on has no sharp edges that might tear the wire during winding, you should, in theory, be able to wind it around the magnets directly. It would take a bit of patience and care, but it's only one pickup, not a volume manufacturing challenge, so the extra hour or whatever is a reasonable investment.

            Any guesses as to gauge and # turns? What does the "good" pickup read in DCR?

            Comment


            • #7
              The old Burns Tri-Sonic pickups were wound like this. I'd bet that top plate is steel. Maybe the bottom too. On the Burns pickups the bottom plate is steel. Then the bobbinless taped coil drops over the ceramic magnet. The Burns pickups look like they have poles, but they don't.
              It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein


              http://coneyislandguitars.com
              www.soundcloud.com/davidravenmoon

              Comment


              • #8
                Originally posted by Joe Gwinn View Post
                I did click on them.
                Those first images are 1600 X 1200 pixels. They open very large in Safari, and I can click to zoom in further.
                It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein


                http://coneyislandguitars.com
                www.soundcloud.com/davidravenmoon

                Comment


                • #9
                  Yes, the top and bottom are steel. The rivets look to be brass.
                  I can't wind the coil directly because the sides of the bottm plate are bent up in the way, unless I drill the rivets out and remove the bottom plate. There are no poll pieces just a black plastic insert cover over the top plate and rivets.
                  I think I'll proceed with a wooden bobbin and wrap with tape idea and I'll keep you posted. Sorry about the pics........
                  Thanks
                  Norm

                  Comment


                  • #10
                    If you make some kind of a coil former that can be collapsed or taken apart. Then you can wind the coil and then wax pot it. When it cools remove it from the form.

                    Kent Armstrong winds his coils that way.
                    It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein


                    http://coneyislandguitars.com
                    www.soundcloud.com/davidravenmoon

                    Comment


                    • #11
                      Screw a couple of sewing machine round bobbins to a wooden faceplate the distance apart determined by a piece of string round the inside of existing coil and wind on them. Tie the coil with lots of bits of cotton and remove by removing bobbins and push into shape and waxpot. Wrap it in cellophane tape and thats it job done.

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                      • #12
                        Thanks guys.....some great ideas, I didn't think of wax potting before I remove it form the bobbin. I've got some nylon material hanging around in my shop (I do guitar repair) that I can make a bobbin with a removable top; should be able to slide the whole thing off after potting
                        Thanks
                        Norm

                        Comment


                        • #13
                          I wonder if these weren't wound on a round form and squished oblong after the fact but before wax potting.

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                          • #14
                            Ah Ha! That's a good question. The bundle does look squished. It looks like the bundle is axially wrapped in clear plastic tape and formed to fit the magnets and base. Can’t tell if it was wound round or race track shape; I don’t think it matters much as long as it fits the space after it’s formed and you don’t break mag wire in the process
                            I’m still contemplating my next move…….

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                            • #15
                              Originally posted by jonson View Post
                              Screw a couple of sewing machine round bobbins to a wooden faceplate the distance apart determined by a piece of string round the inside of existing coil and wind on them. Tie the coil with lots of bits of cotton and remove by removing bobbins and push into shape and waxpot. Wrap it in cellophane tape and thats it job done.
                              I was hoping you would chime in with a good answer! You know them old British pickups.

                              I think I'm going to make a jig like that.
                              It would be possible to describe everything scientifically, but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure. — Albert Einstein


                              http://coneyislandguitars.com
                              www.soundcloud.com/davidravenmoon

                              Comment

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