. The Bell System technical journal . 304 BELL SYSTEM TECHNICAL JOURNAL as discussed in Section Such an antenna is also required to obtainthe high angular precision for anti-aircraft fire control. These require-ments are achieved by the use of a conical scanning system. The beamfrom the antenna describes a narrow cone and the deviation of the axisof the cone from the line of sight to the target can be determined and meas-ured by the phase difference between the amplitude modulated receivedsignal and the frequency of the reference generator associated with the. Fig. 54.—Rocking Horse Fire
. The Bell System technical journal . 304 BELL SYSTEM TECHNICAL JOURNAL as discussed in Section Such an antenna is also required to obtainthe high angular precision for anti-aircraft fire control. These require-ments are achieved by the use of a conical scanning system. The beamfrom the antenna describes a narrow cone and the deviation of the axisof the cone from the line of sight to the target can be determined and meas-ured by the phase difference between the amplitude modulated receivedsignal and the frequency of the reference generator associated with the. Fig. 54.—Rocking Horse Fire Control Antenna. antenna. This information is presented to the pointer-trainer at the direc-tor in the form of a wandering dot on an oscilloscope. The antennas described in sections , and were all designedby the Bell Laboratories as anti-aircraft fire control radar systems, particu-larly for directing heavy machine guns. They were designed for use on alltypes of Naval surface warships. In Radar Kquii)ment Mark 19, the first system to be associated with thecontrol of inch and 40 mm anli-aircraft machine guns, the antenna wasdesigned for operation in the 10 cm region. This antenna consisted of aspinning half dipole with a coaxial transmission line feed. The antenna RADAR ANTENNAS 305 was driven by 115-volt, 60 cycle, single phase motor to which was coupleda two-phase reference voltage generator. The motor rotated at approxi-mately 1800 rpm which resulted in a scanning rate of 30 cycles per antenna was used with a 24-inch spu
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
