RADIO PROGRAMMES

Evening Star, Issue 22817, 27 November 1937, Page 6

RADIO PROGRAMMES

QUESTION OF PRESERVATION “CANNING” OUTSTANDING WORK Present since the inception of the radio era has been the prohlem of retaining a permanent record of the many magnificent programmes offered by this invention. The principle, of the phonographic disc has been applied witt little success, owing to its costly maintenance, and the inability of the disc •to hold a musical continuity of more than three or four minutes’ duration. 4 Thus the Tcflphon, a new invention without either of the above drawbacks, was the source of great interest when shown at the Leipzig fair recently. ' This instrument records a continuous programme of any given length without any supervision, once it has been sot in motion. The notes of music, or sounds of speech, are registered on a film, which can immediately be used to render a repetition of tho presentation just recorded. A film some 100 metres in length will “ play” continuously for about 24 hours. The apparatus in wholly automatic, aiid chronicles the programme with minute exactness. Contrary to the practice of the talking motion picture, the 1 sounds, are not photographed on the film but are engraved thereon by a sapphire stylus. The whole apparatus is attached like ft loud-speaker to the back of the radio, and the broadcast enters a sort of cutting-box wherein the musio is, cut in grooves into the film. A special film which takes impressions on both sides acts as a sound track, while the actual film itself is one continuous roll, beginning and end joined together. One bun*; dred grooves can be cut Into - each roll, at a distance of 0.26 millimetres apart. The film rotates at a speed of 22.5 centimeters per second in the recording of speech, and 45 centimetres per second m the registering of music. A pointer on a scale indicates just how much of the film has been used, and on this scale also can be set -down the names of tho various items re--corded. Each time the film is run off, this scale can be reattached, thus constituting an index to the contents ,of tho rol), and making possible an accurately catalogued library of programmes. Tho turn of a knob sots tho device going, and in the ” playing ” of the film a sapphire stylus must ho used, as in the original rendering. One stylus has a lifetime of approximately 800 hours. Of special interest is the automatic contrivance which removes, by a simple process of suction, the particles of film loosened in the original cutting of the sound grooves in, the roll. The uses of the “Teflphon.” are manifold: Telephone conversations, conferences, court-room proceedings, _ dictation, can all he quite easily “ written” into the film, which also possesses the unique advantage, by means of a switch, of enabling a full halt in the recording to take place, and a complete review of what has gone before to be made, without the necessity of- rolling the film backwards. A roll of film will give 100 “ performances ” without any noticeable degeneration in the quality of the sound, which is quite adequate for most purposes.