Abstract: The invention provides a magnetron drive circuit which drives a magnetron to produce a generally rectangular-shaped narrow transmission pulse having sharply shaped rising and falling edges. The magnetron drive circuit includes a nonlinear load circuit and an active damper circuit. The nonlinear load circuit becomes on at around 80% of a peak output voltage of a pulse transformer (at which the magnetron begins to oscillate) is connected to a secondary winding of the pulse transformer in parallel with the magnetron. The active damper circuit absorbs residual energy left in the pulse transformer without any need for an absorption resistor conventionally connected between both ends of a primary winding of the pulse transformer.

Abstract: The invention provides a magnetron drive circuit which drives a magnetron to produce a generally rectangular-shaped narrow transmission pulse having sharply shaped rising and falling edges. The magnetron drive circuit includes a nonlinear load circuit and an active damper circuit. The nonlinear load circuit becomes on at around 80% of a peak output voltage of a pulse transformer (at which the magnetron begins to oscillate) is connected to a secondary winding of the pulse transformer in parallel with the magnetron. The active damper circuit absorbs residual energy left in the pulse transformer without any need for an absorption resistor conventionally connected between both ends of a primary winding of the pulse transformer.

Abstract: A passive, active or mixed platform type antenna orienting apparatus mounts on a vehicle such as a small-sized vessel or an automobile, which is subject to turns and complex vibrations, traces a target such as a communications satellite with a directive antenna. Between a rotational shaft connected to a platform supporting an antenna and a stationery shaft connected to base to be carried on a vehicle, there is interposed as electric rotary coupling for transmitting power and signals necessary for a transmission signal and an attitude control, so that the platform 43 supporting the antenna 1 may continuously rotate with respect to the vehicle 27. Midway of a post 41, moreover, there is disposed a horizontal damping mechanism 70 which includes a laminate 75 and facial pressure apply means 76 for applying a facial pressure to a laminate 75, to effect a damping action which is excellent in durability and even in the horizontal direction.

Abstract: Position detecting device for use with omega navigating apparatus which includes a receiver for receiving two omega signals from different stations, a synchronous generator for producing first and second signals synchronized with the omega signals and frequency dividing the synchronized signals by a common divisor to produce first and second frequency-divided waves, frequency dividing means for dividing the phase difference between the frequency-divided waves by the period of the omega signals to produce an integral quotient which constitutes a lane number while the remainder represents the phase difference between the first and second omega signals.