In finishing my latest batch of pickups (humbuckers) I had something peculiar crop up. On 2 of the 12, when I put the DVM on them to read the resistance on the final assembly the resistance starts lower than it should and slowly rises to a value near but not quite what it should be - almost as if there's a capacitor charging inside. One is an 8.25k that starts reading at about 8.13 and rises to about 8.21-8.22k. The other is a 7.7k that starts at about 7.3k and rises to about 7.66k. Here's the freaky thing. I rewound one of them, replaced the 2-conductor braided hookup, and it does the same thing. The other 10 pickups don't do this (some are 4 conductor and some are 2 conductor).
I take measurements many times along the way on the individual coils (resistance, inductance, etc.) and also on the final assembly to tell me if something has gone off during the build. When I pulled the pickups apart, the coils measured fine - when I reassembled them - the reading did the same thing. I was near the end of a spool, but wound several coils after these that don't seem to exhibit the phenomenon. I even replaced the hookup wire on both, but I can help but feel the problem lies there somehow.
I had them boxed to ship but I just couldn't do it so I've rewound the coils again and will finish the new set tomorrow. I've never had this happen in thousands of pickups - at least not that I recall. The only thing I can think of is an odd lot of hookup from StewMac. I buy the pre-cut 16" pieces, and pull them out of the box at random.
Hopefully it "disappears" with this rebuild. This kind of thing really sets my schedule back. Any ideas?
I take measurements many times along the way on the individual coils (resistance, inductance, etc.) and also on the final assembly to tell me if something has gone off during the build. When I pulled the pickups apart, the coils measured fine - when I reassembled them - the reading did the same thing. I was near the end of a spool, but wound several coils after these that don't seem to exhibit the phenomenon. I even replaced the hookup wire on both, but I can help but feel the problem lies there somehow.
I had them boxed to ship but I just couldn't do it so I've rewound the coils again and will finish the new set tomorrow. I've never had this happen in thousands of pickups - at least not that I recall. The only thing I can think of is an odd lot of hookup from StewMac. I buy the pre-cut 16" pieces, and pull them out of the box at random.
Hopefully it "disappears" with this rebuild. This kind of thing really sets my schedule back. Any ideas?
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