Leo Fender has always been a tinkerer. Although not being a musician himself, let alone a guitar player, he loved building tools for musicians. And for amplified instruments, it all starts with the pickups. Leo designed the pickups for the Fender Broadcaster/Telecaster when the forties moved into the fifties, and those on the Stratocaster around the midpoint of the latter decade. And here we are, about ¾ of a century later, still using them, emulating them, aspiring to make pickups sound like them. So undeniably the man knew what he was doing. At the inception of G&L, he was at it again and on June 20, 1979 filed for what became US Pat. 4,220,069. The subject? The Magnetic Field Design (MFD) pickup, both a single-coil as well as a humbucker version. As explained in the dealer letter included below, what makes this kind of pickup different from the conventional ones is where the magnetic element is placed. Conventional pickups have magnetic slug pole pieces, whereas the MFD has soft iron pole pieces, which are good conductors of magnetic fields, but a flat ceramic magnet placed just underneath these pole pieces. This gives these pickup a different response with a sensitivity for a wider range of the frequency spectrum, the more since the height of the pole pieces is adjustable.

Although these pickups are mainly found on G&L instruments, the S-500/Skyhawk pickups, also used on the SC-3, were available as an after-market product as early as 1983. As per the January 3, 1983 price sheet, one would order Catalog Number PG 100 for a set which “Fits *Strat-type Guitars”. For a direct replacement of a set on the SC-3, it would be PG 100R. And as indicated, you could even get each pickup separately! The 2 versions likely differed slightly in their overall dimensions and method of mounting, i.e. directly on the body (PG-100R) or on a pickguard (PG-100). The pictured packaging from about a decade later shows multiple sets were available then. The LF-S3 “Pickups for Strat” are compatible to the PG-100 above, and also still available under that name as “Pickups for custom made guitars without pickguards”. The LF-T2 “Pickups for for Tele” are the same as the ASAT Classic MFD pickups. And basses were now also included in the form of “Pickups for P-Bass”, i.e split-coil MFD used on the (2nd style) SB-1 and SB-2 neck.