Many of the pickups designed at Fender were designed by Leo Fender and I’m sure suggestions were issued by players and employees. The same goes for the many models designed at Gibson by Walt Fuller, Guy Hart and especially for Gibson’s most successful pickup, designed by Seth E. Lover, the “Patent Applied For” humbucker. Seth was very much into Amateur Radio and liked experimenting with inductors and transformers. At Seymour Duncan a custom pickup made for a client could eventually be made into a new model for a particular instrument. Another great independent designer by the name of Ray Butts designed the Gretsch Filtertron working along side Chet Atkins.