Abstract: A modular rotary disc drive or disc file having three major subassemblies. These are a rotary actuator structure subassembly having an actuator housing and a pivotally mounted actuator member in said housing, an armstack subassembly including the transducer heads and their electric circuits including the plug terminal therefor, and a magnetic driver subassembly having a magnetic housing and a movable coil assembly. The armstack subassembly is attached and removed from the actuator member without removing the actuator member from the actuator housing. The magnetic housing of the magnetic driver subassembly is secured to the actuator housing and its moving coil assembly is secured to the actuator member. This magnetic driver subassembly is also attached and removed as a unit without removing the actuator member from the actuator housing.

Abstract: A shaft assembly of a rotary actuator arm structure in a rotary disc memory drive in which all machine operations cutting slots or openings for receiving leaf springs which provide axial and radial loads are performed along axes paralleling the axis of the rotary actuator. One leaf spring provides an axial load on the bearings of the shaft assembly. A second leaf spring fitted between one shaft bearing and the bearing housing thereat provides the radial bearing load.

Abstract: Two transferred electron devices are provided in a thermally coupled relationship. One transferred electron device is operated above threshold voltage as an amplifier or oscillator, while the other transferred electron device is operated below threshold voltage so as to supply heat to the first device, to compensate for any operating temperature changes and thereby maintain the first device at a substantially constant temperature.