How to Build a Relay Coil Pickup

by Cigar Box Nation member, “AL”

A quick making of: The Neck Pickup,

After building a new neck and glueing the fretboard I had to cut of some inches and thought about using the scrap piece as a neck pickup housing for my current three string project.

Unfortunately the space is really limited for placing a hand wound single coil in it ( …and for me pickup winding is an annoying, less relaxing job) so I decided to order some miniature relays (10 for about 10$) with a coil resistance of 2.3 kohms each.The first five coils died during the coil remove surgery at various steps (open the housing, removing the coil with its mounting bracket, removing the mounting bracket…throwing the coil on the floor after sucessfully perform the previous steps 😉 since the wire is ULTRA thin……a 0.063mm standard pickup wire is a massive rod compared to the wire they use for those relay coils.

But after some practice I easily removed three coils in a row without killing one

To avoid microphony, I used a carnauba wax solution normally used to seal hardwood floors or furniture (such as guitars :-). Its important to check if there is any agressive thinner in the wax solution which possible can attack the isolation coat of the copper wire.

To get the wax deep into the coil I used a syringe with a three way valve (a simple plug would do it also) throw the coil into the syringe, Fill the syringe with wax until the coil is fully covered, press as much air out as possible, close the syringe and pull the handle to the top end of the cylinder, hold it in place and watch until the amount of bubbles coming out of the coil is negligible (1-2 min)……now the coil is vacuum waxed and should dry for a couple of hours.

The housing was made of a neck scrap piece using drills and Dremel. Further steps: placing the coils in the housing, soldering the coils in series, check if nothing went wrong by using an Ohmmeter, adding small neodym magnets to the pole plate and pour some clear epoxy into the cavity.

A little sanding finish and done. Great sound, super small, nice distance to the strings, building time 45minutes, less than 5bucks needed for materials (after learning how to remove the coils without breaking the wire :-).

Have fun