American television directory (1946)

Record Details:

Something wrong or inaccurate about this page? Let us Know!

Thanks for helping us continually improve the quality of the Lantern search engine for all of our users! We have millions of scanned pages, so user reports are incredibly helpful for us to identify places where we can improve and update the metadata.

Please describe the issue below, and click "Submit" to send your comments to our team! If you'd prefer, you can also send us an email to mhdl@commarts.wisc.edu with your comments.




We use Optical Character Recognition (OCR) during our scanning and processing workflow to make the content of each page searchable. You can view the automatically generated text below as well as copy and paste individual pieces of text to quote in your own work.

Text recognition is never 100% accurate. Many parts of the scanned page may not be reflected in the OCR text output, including: images, page layout, certain fonts or handwriting.

THE BELL SYSTEM’S PLAN FOR TELE-NETWORKS Construction of nationwide networks, already well started, will continue to keep pace with the require¬ ments of this rapidly expanding broadcasting medium. By KEITH S. McHUGH Vice President, American Telephone and Telegraph Company ACROSS THE COUNTRY, mile by mile, automatic coaxial cable laying under the sponsorship of the Bell System is linking major communities together, speeding the day of nationwide television. About 400 miles of a 7,000-mile network is in operation at the beginning of 1946. CROSS SECTION of a six-coaxial cable (left) shows position of coaxials with respect to regu¬ lar telephone wires. Fanned-out view of cable at right shows construction of conductors in the one sheath. Width of waveband carried depends on amplifying equipment, not on cable. T he Bell System is preparing to meet the television industry’s needs in transmission facilities as they arise. That unqualified statement can be made because of the background of ex¬ perience and resources that has been accumulated by the telephone industry. For nearly three-quarters of a century, telephone engineers have been develop¬ ing successfully the art of transmitting electrical impulses over long distances. For some 20 years we have been oper¬ ating successfully nationwide networks for radio broadcasting. And backing up such experience are an incomparable physical plant, a thoroughly trained personnel, and the research achieve¬ ments of the Bell Telephone Labora¬ tories. Bell System facilities for broad-band transmission have proved capable of transmitting either telephone calls or television programs satisfactorily. They will be ready to meet television’s ex¬ panding requirements in quality of transmission and in dependability as rapidly as the art develops. What type of equipment will the Bell System use in serving the television industry? Coaxial cable and speciallyequipped telephone wires already have proved capable of carrying broad-band television frequencies. Radio relay serv¬ ice may also prove attractive in broad¬ band transmission. Our objective is to provide the best, most dependable and most economical transmission method. We shall use whichever method or com¬ bination of methods gives the television industry the most satisfactory service at the lowest practical cost. Coaxial Cable In the years prior to World War II, as it became apparent that increasing telephone traffic would outstrip the ca¬ pacity of conventional wires and cables on major toll lines, telephone engineers looked for a transmission method that would accommodate the expected in¬ crease in volume of calls. They adopted the coaxial principle and developed a cable that could carry many hundreds of phone conversations simultaneously without mutual interference. Essential¬ ly, a coaxial cable is a wire conductor within a cylindrical copper tube which serves as both a return conductor and a shield. Simple though it is in design, coaxial cable when suitably equipped efficiently transmits the broad frequency bands required for multiplex telephony and television. Present coaxial equipment can trans¬ mit frequency bands of about 3 mega¬ cycles. Experimental work, started be¬ fore the war and being resumed now, however, indicates that, with further development, bands of greater width can be accommodated should television need them. The first coaxial cable to be placed and used for telephone messages by the Bell System was a 90-mile section be¬ tween New York and Philadelphia, in¬ stalled in 1936. This was followed by a 200-mile length between Stevens Point, Wis., and Minneapolis, which has been in operation for about five years. The ( Continued on page 128) 25