Journal of the Society of Motion Picture and Television Engineers (1950-1954)

ing into account the reduction in response of the eye to fine detail and the reduction in response of the projection equipment to high-frequency components. The weighting factor was based upon a viewing ratio of 2. C. System Linearity. It was proposed that the system be sufficiently linear so that the maximum deviation of the transfer characteristic from a straight line joining the ends of the characteristic at black-and-white levels should not exceed 10% of the total excursion from white level to black level. II. Channel Width In order to transmit satisfactorily a video signal having the above specifications, it was proposed that a channel width of 30 me be provided for carrier frequencies below 10,000 me, and 55 me for carrier frequencies above 10,000 me. III. Number of Channels Provision was requested for a total of six independent circuits. It was shown that each circuit would require two channels so that a total of twelve channels would be required for six circuits. This would require a total of 12 times 30 me, or 360 me. In addition, two pooled channels were requested for remote pickup use. IV. Position of Channels in Spectrum Two alternative proposals were made for re-allocation of the microwave spectrum in order to provide an allocation of channels for theater television. These are summarized below: Proposal No. 7 a. Allocate the frequencies from 5925 to 6285 me (now allocated for common carrier fixed services) for the exclusive use of theater television. b. Provide a reasonable transition period within which the present occupants of the frequencies in a. above can move to some frequency between 6285 and 6425 me which would be retained by the common carrier services. c. If necessary, additional frequencies, e.g., the 3500 to 3700-mc band could be allocated to the common carrier fixed services to compensate for this loss of the 5925 to 6985 me band. Proposal No. 2. If it is decided that the exclusive type of allocation for theater television contained in Proposal No. 1 is not feasible, it is suggested that provision for theater television be made in the rules on a frequency-sharing basis with the operational services. This could be accomplished as follows : a. Classify theater television as an industrial radio service. b. Expand the 6575 to 6875-mc operational fixed band downward to include the land mobile frequencies between 6425 and 6575 me, thus providing sufficient bandwidth for theater television requirements. Television in the Armed Services The Signal Corps Mobile Television System has provided a means of exploring the use of television as a tactical and training medium in the U.S. Army. The system provides, in mobile form, self-contained and self-powered equipment for lighting, for television, and for technically controlling the production of scenes from three field cameras. The combined audio and video can be fed simultaneously to kinerecording equipment and via microwave radio transmission to a remote receiver. Other mobile units provide for receiving and monitoring sound and video signals at the receiving point. Provision is also made to display the resulting television production to audiences on ten 16-in. monitor receivers and on a 6 by 8-ft projection receiver.37 Television equipment was successfully employed in launching a number of robot planes, or drones, against Communist targets in North Korea from the U.S.S. Boxer, a 27,000 ton Essex class aircraft carrier. While details of the Navy's system are secret, the drone bombing attack George R. Groves: Progress Committee Report 547