There were several types of pickups used on K & F and Fender lap steels. In Leo’s and “Doc” Kauffman’s early patent number 2,455,575 filed on September 26, 1944 and granted on December 7, 1948 there are several components. The bobbin consisted of a Vulcanized bobbin with 6 tubes in which the strings would go through without touching the walls of the cylinders. The pickup used two Alnico bar magnets and held in place by two fabricated case hardened steel shells and the bottom shell or case would support the string and guide it through the cylindrical tubes. The case hardening keeps the string from cutting into the edge of the material.

The strings were actually through the center of the coil. The pickups looked rectangular from the top. The front side of the shells or casing are notched between each string to focus the magnet field to the strings. Each end of the pickup uses a sand cast Alnico magnet with the same polarity facing up on each end. Below are some winding specs for a few “Direct String Pickups” where the strings go through the pickup.

Fender Lap Steels that I’ve evaluated:

The Direct String Pickups use two Vulcanized fibre flatwork and often a clear vinyl plastic, computer cards or thin fibre board was used for the center of the bobbin. Spacers of wood or plastic was used to help keep the materials from warping over time. On the Custom Lap Steel pickups the coil had to be wound off center on the bobbin. The pickups were also wax potted to help eliminate unwanted feedback and added protection to the coil. A small piece of fibre or cardboard was usually placed over the eyelet’s so they didn’t short out with the metal case of the pickup.

The Stringmaster pickup assembly used two pickups each wound and magnetized opposite of the other. The pickups are connected to a potentiometer to blend one pickup in and out for single to a dual humbucking sound. Over the years many Champion lap steel pickups were removed and modified to fit the bridge position on Telecasters.