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Help with vintage DeArmond pancake pickup

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  • Help with vintage DeArmond pancake pickup

    I'm a folk instrument builder, and I have taken on the restoration of a 1966 Kay guitar with "zippo" pancake pickups. The original neck pickup has an output of 5.665k, and has a wonderfully full tone. The bridge pickup was dead, so I've been doing research and trying to rewind it. I used a heat gun to soften the wax and free the spindle. Cleaned up the spindle, replaced card stock top plate with one made from scrap pickguard material, and pop riveted the spindle back together. The magnet seemed weak to me but comparable to the one in the neck pickup so I reused it. I insulated the spindle with black electrical tape and 2 coats of shellac varnish. I put 5,000 winds on the spindle and soldered the leads, neg lead to the inside, and positive on the outer side. My rewound spindle produced 4.09k output, but it sounded horribly thin and muddy. I attempted to rewind it again, 5,200 windings, 4.11k output, and replaced the magnet with a similar sized neodymium bar. Once again I got weak, tepid, muddy tone. I've tried reading the FAQ and searched for suggestions, but I can't see where the coil could be shorting on the magnet or spindle as I've taken care to insulate it well. Could I have a bad spool of wire? I'm using Remington #43 enameled copper.

  • #2
    Hi G.S. Monroe:
    Any pictures you could post might help.
    Not sure of bobbin size, but 5300 turns of 43, I would think would be more than 4.11k ohms.
    Can you measure the diameter of the old wire? That will tell gauge.
    You say negative lead to inside (Start Lead), and positive to the outer side (Finish lead).
    What you call neg. , should be ground to a pot back.
    pos. would be + output, to a switch or Pot.
    Make sure the Start lead is not shorted to ground or the covers.
    T
    "If Hitler invaded Hell, I would make at least a favourable reference of the Devil in the House of Commons." Winston Churchill
    Terry

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    • #3
      I don't have any pictures yet of the bare spindle, but I will post what I do have to show what kind of pickup I'm working with. I don't believe the coil wire is shorting to the cover because of a thick coat of wax.


      I will be taking it apart again on Monday and trying again. This is the first pickup I've attempted to rewind, and I didn't save any of the original coil wire. I do have some experience in harness wiring, and I have been careful to check polarities and proper grounding, but I will continue to troubleshoot it.
      Attached Files

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      • #4
        When you take it back a part?
        You can measure the bobbin, and calculate how the wind will come out using the coil estimator.
        Coil Estimator
        find a similar pickup and alter the dimensions with the coil estimator.
        Or give us the dimensions, and we will help you with it.
        If anyone is familiar with this pickup, please jump in?
        T
        **BTW: welcome to the B/H forum!
        "If Hitler invaded Hell, I would make at least a favourable reference of the Devil in the House of Commons." Winston Churchill
        Terry

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        • #5
          Just by looking at the coil estimator, and knowing the "ball park" dimensions of my spindle, is it possible that I'm winding the coil too loose?
          The magnet core is 1/4 inch thick, 3/8 inch wide, and 2-1/8 inch long. The flange extends 5/8ths. I completely filled the coil with 5,200 winds but the calculator indicates I can get over 6,000 using #43 gauge wire. I know I'm a bit timid about wire breakage, and I wind carefully and at a slower speed (@ 300-500 winds per minute) with a manual hand cranked winder.

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          • #6
            Originally posted by G.S.Monroe View Post
            Just by looking at the coil estimator, and knowing the "ball park" dimensions of my spindle, is it possible that I'm winding the coil too loose?
            The magnet core is 1/4 inch thick, 3/8 inch wide, and 2-1/8 inch long. The flange extends 5/8ths. I completely filled the coil with 5,200 winds but the calculator indicates I can get over 6,000 using #43 gauge wire. I know I'm a bit timid about wire breakage, and I wind carefully and at a slower speed (@ 300-500 winds per minute) with a manual hand cranked winder.
            Length, width, height, flange.
            L=2.125, width=.375 ?, Height=.25 inch ?, flange=.625" ?
            Or
            L=2.125, Width=.25, Height .375, flange=.625 ?
            "If Hitler invaded Hell, I would make at least a favourable reference of the Devil in the House of Commons." Winston Churchill
            Terry

            Comment


            • #7
              It's a very low profile, flush mount pickup. The height of the magnet is .25 inch, and once you add top and bottom flange fits inside the 3/8 deep casing. I will be pulling it apart on Monday when I return to the shop. I will get detailed pictures of the assembly. This may help https://youtu.be/H-32k-U3yIA

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              • #8
                Originally posted by G.S.Monroe View Post
                It's a very low profile, flush mount pickup. The height of the magnet is .25 inch, and once you add top and bottom flange fits inside the 3/8 deep casing. I will be pulling it apart on Monday when I return to the shop. I will get detailed pictures of the assembly.
                If that is the case, then I show the bobbin to be full at 4k ohms.
                See screenshot
                The wire you took off is probably 44AWG.


                Click image for larger version

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                "If Hitler invaded Hell, I would make at least a favourable reference of the Devil in the House of Commons." Winston Churchill
                Terry

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                • #9
                  Here's a YouTube clip from Clint Searcy doing a rewind on one of these Kay "Zippo" pickups.

                  He gives the specs as 5000 CW of 43 AWG, which looks like SPN. He also explains the mags are much weaker than a strat and shows them at 140

                  https://youtu.be/H-32k-U3yIA


                  Edit: oh, I see you have found that video. WHat about this one https://youtu.be/vJryzZBNSHc

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