Switch polarity to get rid of 60-cycle hum
For more than 50 years, the Fender Telecaster has been manufactured pretty much the same way. It’s trademark sound is one of raw, gutsy tone with sharp attack and great clarity. Because of it’s simplicity and honesty, it is perhaps the best way to showcase a pair of single coil pickups. One of the drawbacks of true single coils is their hum which guitar makers have been trying to fix for decades. Since the Telecaster’s design was perfected rather early on in electric guitar history (1950) it is one of the only dual pickup guitars that did not have hum-canceling capabilities, and it still doesn’t today. Most of the time the two pickups are made reverse-wound/reverse-polarity so that when they are used in combination (the middle position of your pickup selector) they will cancel the hum. The telecaster design has been pretty much left alone because so many players love the trademark sound and especially the sound you get when the neck and bridge pickup are played together. For a lot of players that is more important than “bucking” the hum, but for you it might be more important to have a quiet setting on the guitar. Here I will show you how to cheaply and easily buck the hum on a standard Telecaster.
As we just discussed, most Tele pickups are wound the same direction and charged with the same polarity facing up, making them non-humbucking, so all you need to do is switch the leads and reverse the polarity on one pickup. You can test the polarity by holding a compass up to the top of the pickup as shown below. Opposites attract, so this pickup is charged SOUTH UP (fig. 1).
Reversing the leads on a pickup is a simple operation with a soldering iron, but charging the magnets will be a little more tricky. Especially since most vintage, and vintage-reissue Telecasters have a copper-plated steel baseplate on the bridge and a chrome cover on the neck pickup, which is soldered to the ground of the guitar.
Modern American Standard bridge pickups, like the one shown below, do not have a baseplate, and are changed NORTH UP (fig. 2), so here I will remove the pickup and charge it SOUTH UP.
This can be done with a pair of 1″ rare earth magnets from Steward-Macdonald
($8.57 each). These are extremely strong magnets that will successfully charge Alnico polepieces like in my pickups here. They will also successfully erase hard drives like in you iPhone or MacBook, so keep them away from all computerized equipment. You can see the magnetic field you are dealing with by holding it to a compass . It is attracting the NORTH needle, so this is the SOUTH pole of the magnet (fig. 3).
Charge the pickup polepieces by moving them back and fourth between the rare earth magnets. The magnets will change magnetic fields of weaker magnets to what they are most attracted to, so a SOUTH pole with charge pickup polepieces to be NORTH. Rare earth magnets will hold themselves to the jaws of a vice. Label the side that will charge magnets to be North as I have done below (fig. 4).
Adjust the jaws so that the magnets are as close as possible to the polepieces but still allow the pickup to pass freely. Move the pickup through the jaws of the vice a few times and it is fully charged. Reinstall the pickup with the leads reversed. Positive leads are usually white or yellow and in this case would be soldered to the ground (the back of the potentiometer), negative leads are usually black, blue or green and in this case would be soldered to your switch.
If this pickup had a metal baseplate (fig.5) or a cover it would be a little more difficult to charge the magnets but sill possible. It would require disconnecting the negative (ground) lead from the baseplate or cover and running a separate ground wire from the baseplate to the back of the potentiometer. Then, special care must be taken to break the hold of the potting wax and remove the baseplate or cover without damaging the coil. Then you can charge the magnets.
Now you have a hum-canceling mode on your Tele without effecting the tone of the bridge or the neck pickup!