Abstract: An actuator (100) which comprises a motor (1), a housing (2) which wraps a periphery of the motor (1), a drive mechanism (3) of which one end is provided with a push rod assembly (34); under the function of the motor (1), the push rod assembly (34) moves forward; wherein, a returning spring (4) is arranged along external sides of the housing (2) and the drive mechanism (3), and the two ends of the returning spring (4) are respectively connected at the housing (2) and the push rod assembly (34); under the force of the returning spring (4), the push rod assembly (34) moves backward to an initial position of the push rod assembly. The actuator is simple in structure and has self-returning function.

Abstract: A variable RF inductor network having a plurality of coaxial cables with their respective outer conductors in electrical contact with each other, thereby forming a common outer conductor. This common outer conductor is connected to an RF ground and an RF source. An RF choke is formed between the RF ground and RF source by winding the coaxial cables around a first of a series of inductor cores. The coaxial cables are then wound serially about the remaining succession of inductor cores to form serial, separate inductors. At each separate inductor core, one of the cables is terminated and the inner conductor of the terminated cable is connected to a PIN diode switch for switching the particular inductor out of the network by shorting the common outer conductor across the core. The inner conductors are connected to a biasing means for individually controlling each PIN diode switch to selectively switch particular inductors in and out of the network.

Abstract: A frequency selector (tuner) employs a turret to select the position of a slide member that is coupled to a variable reactance. The slide member is moved away from the turret by depressing an operating member and returns to the turret when the operating member is released. Depressing the operating member rotates the turret concurrently with the movement of the slide member, but interference between the slide member and cooperating position setting elements that project from the turret is avoided by a displacement mechanism on the slide member. The projection of the position setting elements is adjusted by turning the operating member. A further operating member is provided for turning the turret in opposite directions, the final position of the slide member being set by depressing the first-mentioned operating member.