I often have people bringing me faulty pickups. Sometimes it turns out there's just a loose wire and simply needs re-soldering. But sometimes the pickup needs re-winding.
With humbuckers its only usually one coil in which case I can measure the working coil and match the re-wind to it.
Its more common that I get Fender single coil pickups with faults. Older fender pickups can have problems with the insulation on the windings breaking down and the pickup looses its power and becomes thin and weedy sounding.
This is my winding machine. It lives in the corner of the workshop and a lot of customers comment on it.
It isn't possible to wind completely by hand as there are 7500turns on an old Strat pickup and more on a hot one.
The pickup bobbin attaches to the rotating spindle on the front of the machine (white).
The wire is very fine - its about as thick as hair and more brittle as ist made of copper. It's not cheap - the thinner it is the more expensive. I have a few guages for different pickup sounds.
The wire passes over a series of pulleys to tension it.
The machine has a counter with a cut off which stops winding when it gets to the correct number of turns.
so here's the finished product - an old Strat pickup restored to its former glory.
Glyn