Rotary input switches
Type W, Type 82, Type 3A7, and early Type 1A1 plug-ins have a rotary input coupling switch that is concentric with the BNC input connector. This same switch also shows up on the prototype Type J, which never went into production. The Tek part number is #260-0603-00. Minor oxidation of the contacts can be cleaned using a regular contact cleaner spray. This switch can be disassembled for further cleaning/repair. See repair page for disassembly instructions.