Radio age research, manufacturing, communications, broadcasting, television (1941)

Portable Television Transmitter And Camera Using Pencil-Sized Tubes and Miniature Components, RCA Develops Back-pack Unit Weighing Only 53 Pounds and having Range of One Mile. 1 ANEW portable television cam- era and transmitting station, designed to operate in the field as a one-man back-pack unit, was dem- onstrated by L. E. Flory, of the RCA Laboratories, at a meeting of the Institute of Radio Engineers on March 21. Weighing only 53 pounds, the back-pack station is planned to function with its own battery-power supply. It has a range of approxi- mately one mile. Because of its easy portability, numerous appli- cations for the new equipment are foreseen by RCA research engi- neers. Among these are news cov- erage, with television-equipped re- porters flashing pictures and com- mentary directly to editorial rooms, and remote industrial viewing and control. The new transmitter operates in conjunction with a control station which may be located as far as a mile from the camera. Signals cor- responding to the scene being tele- vised are transmitted to the control point on an ultra-high frequency with a power of two watts. In addi- tion to acting as a monitor for the televised picture, the control point performs two other functions. It sends out a stream of pulses which stabilize the camera and can be used also to issue vocal instructions to the cameraman. Recent developments in the de- sign of pencil-sized tubes and other sub - miniature component parts made possible the impressive re- duction in bulk and weight of the equipment. Equifnnent Carried as Back-Pack The back-pack is carried in knap- sack fashion, suspended from the narrator's shoulders by flexible straps. Two small antennas extend from the top of the pack and are used respectively to transmit the picture signal to a base station and to receive voice and control signals from that same point. The camera is an adaptation of the RCA industrial TV camera using the Vidicon tube. As an added feature, the camera includes a miniature kinescope picture tube which serves as a view-finder for the cameraman. Through it he is able to see an exact reproduction of the scene on which the camera lens is focused. The equipment contains 42 tubes which, with their associated cir- cuits, pi-ovide all synchronizing fre- quencies for a standard 52o-Iine, 30-frame interlaced television pic- ture. Included in the unit are the battery-operated power supply, de- flecting circuits, amplifiers, and a radio receiver for receiving instruc- tion and other essential information from the control point. A single battery operates the portable sta- tion for about 1^2 hours. The narrator-cameraman's voice is picked up and transmitted through the combination of a small microphone built into the camera case and an ingenious electronic circuit which adds the voice signals to the picture signals as they are radiated to the control point. Research and development of the portable television equipment were carried out by Mr. Florv, W. S. Pike, Jr., J. E. Dilley, and J. M. Morgan, of the RCA Laboratories, under the direction of Dr. V. K. Zworykin. Vice President and Tech- nical Consultant. CO.NTROL PANEL OK PORTABLE TV SYSTEM. I.NCLUDING MONITOR SCREEN AND TWO-WAY RADIOTELEPHONE FACILITIES. SIDE VIEW OF PORTABLE TELEVISION CAMERA, SHOWI.NC; VIDKO.V TUBE (UPPER RIGHT) AND CO.NTROL UNITS.