Abstract: A drive control device for an electrically-driven extending and retracting antenna such as an antenna on an automobile including a motor-driven rotary plate which makes approximately one revolution during the time for complete extension or retraction and has attached, on one side, a disk-shaped conducting part with a small cut-out. Of the three contacts, the first is ordinarily in contact with the disk-shaped conducting part, maintaining a state of electrical continuity, the second contact contacts the small cut-out when extension of the antenna is completed; and the third contact contacts the small cut-out when retraction of the antenna is completed. As a result, electrical continuity is maintained during extension or retraction of the antenna, but not when extension or retraction has been completed. The first and second contacts thus constitute a limit switch for antenna extension; and the first and third contacts constitute a limit switch for antenna retraction.

Abstract: A multistage extensible rod antenna system including a plurality of conductive rods which have different diameters, respectively, and are connected in a freely slidable manner to each other. Each of the conductive rods is provided, along its inner circumferential wall of the upper end portion, with first and second stepped portions of different diameters. The first and second stepped portions hold a first collar and a second collar, respectively with an elastic sealing ring therebetween. The upper end face of each of the rods is formed into an engaging portion to keep the collar from slipping off. The multistage extensible rod antenna system thus structured creates less compressive force on the elastic sealing ring, prolonging the elasticity of the sealing ring and extending the service life of the multistage extensible rod antenna system.

Abstract: Disclosed is a car antenna system which comprises a substantially cylindrical mounting base having a conductor fitted therein and penetrating a car body wall, a mounting member shifted along the mounting base and fixed, a fixing means formed of an insulating material shifted by the mounting member to fix the mounting base to the car body wall, a rod antenna element attached to the outside end of a conductive part of the mounting base, and a loading coil located inside the car body wall and connected between the conductive part and a cable led to a CB-wave transmitter-receiver whereby, the capacitance between the car body wall and the conductive part being lower as compared with a case in which the mounting member is not included.

Abstract: A car antenna system comprises an expansion-type antenna element, a driving wire with one end connected to the driving end of the antenna element, a wire transfer mechanism to expand and contract the antenna element by transferring the driving wire in the longitudinal direction thereof, a motor for driving the wire transfer mechanism, a driving power supply circuit including a first power supply circuit for rotating the motor in one direction and a second power supply circuit for rotating the motor in the opposite direction, and first and second circuit breakers connected, respectively, to the first and second power supply circuits for breaking overcurrent flow in each corresponding power supply circuit when the antenna element reaches the expansion or contraction limit.