The talking machine world (Jan-June 1925)

88 THE TALKING MACHINE WORLD May 15, 1925 Discusses Construction and Acoustical Features of the Brunswick Radiola Dr. Alfred M. Goldsmith, Chief Broadcaster Engineer of the Radio Corp. of America, Is the Author of an Interesting Article Entitled "Radio Engineering and Phonograph Engineering" One of the very interesting articles in Highlights of Radio Broadcasting, a publication written in its entirety by Dr. Alfred M. Goldsmith, chief broadcaster engineer of the Radio Corporation of America and widely known in radio circles throughout the world, is entitled "Radio Engineering and Phonograph Engineering." This article, which is devoted to a most important discussion of the constructional and acoustical features of the Brunswick Radiola, reads as follows: Engineering forever widens its scope, and new fields which are at first developed by a Brunswick Radiola hit-or-miss method gradually become the subject of orderly and rapid development by skilled engineers. No devices more fully illustrate this evolution from chance trials to systematic technical improvement than those two related instruments: the radio receiver and the phonograph. The nature of the music originally put out by phonographs, and later by the first radio loud speakers, "designed" by a wild guess, is too notorious to require comment. When it is contrasted with the superb effects whieh can be obtained to-day under suitable conditions, the debt owed to engineering becomes evident and the possibilities of the future are seen to be even more attractive. Up to the present the acoustic problems in the production of desired sounds have been very similar for the radio receiver and the phonograph. Each uses a small vibrating sheet or diaphragm to produce the sounds. In the case of the phonograph, the diaphragm is generally a circular piece of mica mounted in the reproducing head of the phonograph and vibrated by mechanical connection to the needle resting on the record. In the case of the radio loud speaker, an iron diaphragm (or one of other suitable material) is vibrated electromagnetically through the agency of currents which are produced by the radio receiver and its amplifier. The defects of such diaphragm systems may be very serious unless every feature of the dimensions, mounting and control of the diaphragm is thoroughly understood and accurately worked out. The sound produced by the diaphragm in each case passes through and is modified by a horn, and here again is ample opportunity for bad or good design and objectionable or desirable results. The material of the horn, its size, shape and mode of attachment are all of importance, and require careful study and experimentation to get the best results. The radio receiver has the best of the problem, in one way, because one can, after all, increase the amount of available power for vibrating the diaphragm as much as may be desired by radiotron tube amplifiers, whereas the power obtainable from a needle riding in the groove of the phonograph record is strictly limited. Each field has found its own acceptable solutions, and satisfactory results are now being obtained. The output of a phonograph and that of a radio receiver are not so much alike nor so competitive as is sometimes believed to be the case. A phonograph record is of course a reasonably permanent article. Even if the record is worn out, it can be replaced by the purchase of a duplicate. It represents the result of a considerable number of rehearsals of the artist, and may fairly be assumed to be the best recording possible of the particular selection. The broadcast performance is, generally speaking, final — that is, if it is not quite what the broadcaster desired, it can nevertheless not be recalled or modified. And, as a general rule, it is heard once, and is not available for indefinite repetition. A phonograph record can also give the auditor music or speech from persons who are unavailable at the time, either through absence or death. The broadcaster must confine himself to personalities and performances of the present unless he too uses records for his "raw material" for broadcasting. Unless one has a great number of broadcasting station programs at his choice, the phonograph will be more likely to furnish exactly the type of music which is wanted at the very moment it is desired, always assuming that the user is financially very solvent and willing to purchase the assortment of records required for his desired range of entertainment. The capabilities of the radio receiver are unique in a number of respects. An important speech is to be delivered on a given evening. It can reach a million homes by radio, with all the timeliness and personal interest which attaches to it. It can carry to the radio audience the words of the greatest statesmen or leaders in other fields of activity at the instant they are spoken, and with all the delicate individual touches which make such speeches so interesting. This is not possible of achievement in the form of a permanent record, the psychology of the response to the record being quite different from that of the reaction to the actual broadcast speech. Broadcasting can carry the best concert being given in a group of citie = even at considerable distance from each other. SHELTON ELECTRIC CO., THE SHELTON Electric Motor The "Simplicity" electrifies Victor, Edison and Columbia phonographs by simply taking off winding handle and placing motor against turntable. Automatic switch in motor operated when the turntable is started or stopped. Operating on AC or DC current of 110 volts. Specify type of current when ordering. THOMPSON AND MANLEY STREETS LONG ISLAND CITY. N. Y. to all residents of the great area surrounding these cities, and at the very instant that the concert takes place. It can give performances lasting for many hours, where the trouble and expense of gathering approximately the equivalent entertainment in phonograph records would be prohibitive even if, indeed, it were not frequently impossible to assemble the desired pro^ gram in the form of records. The continuity of the performance of a play or an opera is not disturbed in radio broadcasting, and it is an admirable means of bringing the most recent artists and aspirants before the entire public and probably before their efforts have been in part stabilized in record form. The recent rapid development of the radio drama and of political broadcasting indicates other fields which will in all likelihood remain exclusive to radio. The romance of radio is replaceable in no other way. Through the miles of darkness, carried by no visible force, come the concerts and speeches which entertain and instruct the radio listeners. There is and must always be a thrill in the knowledge that an annihilator of space has been placed at the disposal of mankind. Men have always felt the cramping limitations of their own slow capabilities of travel. The task of carrying oneself to a distant city is sufficiently trying to make its elimination by radio a permanent and stable human asset. It is therefore logical to expect that radio and the phonograph will be, to some extent, mutually supplementary. Each will supply its Panel for Brunswick Radiola quota of enjoyment in its own way and utilize its own capabilities to the full. The combination of the two fields of endeavor is, in fact, rapidly proceeding in certain technical directions. The first of the accompanying photographs shows a radio receiver specially designed for inclusion in the cabinet of a certain console phonograph. The most noticeable and unusual feature of this receiver is its careful adaptation to phonograph requirements, and in particular its careful panel arrangement. The appearance of the combined phonograph and Radiola receiver is shown in the second accompanying photograph. The possibilities of such an instrument are indeed striking. One listens to one's favorite broadcasting station concert and then, deciding to hear some particular favorite dance or song, one has only to play the desired record on the same instrument and to hear the music coming from the same horn. The scope of each instrument is therefore widened by the combination. It seems likely that the development of the radio field will again show, as has repeatedly been . the case, that new scientific inventions do not necessarily supersede existing agencies but that they supplement them and broaden their usefulness. J. F. Hilliard Made Manager Hollywood, Cal., May 4. — J. Fred Hilliard was recently selected as manager of the local branch of the Piatt Music Co. Mr. Hilliard has been identified with the Piatt organization for three years and has had a wide experience in the retailing of musical instruments. He is wellknown to the Coast trade. The Paper Radio Corp., Jamaica, L. I., N. Y., has been incorporated at Albany with a capital stock of $5,000. The incorporators are W. F. Pape, C. D Heckman and W. B. Philipbar.