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Die Zeitschrift "audio-record" - Was ist (war) das Besondere ?

Diese Firmen-Zeitschrift war Jahrzehnte verschollen. Doch da stand eine Menge über den nationalen amerikanischen unabänderlichen Weg zum ungeliebten (und teilweise diffamierten) deutschen Magnetophon-Tonband drinnen. Mit diesen Informationen kann jetzt eine Menge an Schallplatten-Historie und ganz früher Magnetband-Historie "gerade gerückt" werden.


Ein kurzer Blick auf die Neuzeit : "Wem die Stunde schlägt."

Ein Film von 1942

Werfen wir einen Rück-Blick auf die weltweite Situation beim Übergang von der analogen auf die digitale Magnetband- technik zwischen 1982 und 1986. Nicht nur Telefunken sowie die Japaner, auch die Firma Willi Studer entwickelten digiale Profi- PCM- Bandmaschinen mit 16 oder 24 digitalen Kanälen. Und das waren Riesenmonster. Und dann passierte das eigentlich visionär "Vorhersehbare" und diese Technik war damit abrupt vorbei. Diese Story steht hier:

Die Willi Studer Story - "Wem die Stunde schlägt" - oder auch "Die DAT Legende".

Und genau das scheint hier im November 1946 auch geschehen zu sein. Die ganzen Rundfunk-, Schallplatten- studio- und Plattenhersteller- Mitarbeiter sowie deren Manager und die sonstigen Beteiligten standen staunend vor einer völlig irren Technik - aus dem mühsam besiegten NAZI-Germany, - die sie ziemlich unerwartet traf und damit virtuell umwarf.

Diese Technik war ganz erheblich besser und vor allem wesentlich flexibler als die besten Schallplatten-Techniken. - Ich vermute, den meisten der Zuhörer bei den Vorführungen der OTS (Office of Technical Services) in 1945 und 1946 war recht schnell klar, es ändert sich - in Kürze - unheimlich viel und alle müssen mitmachen, sonst fallen sie einfach hinten runter.

Gleiches galt auch für die Einführung des UKW/FM-Rundfunks in USA. Und im Land der unbegrenzten Möglichkeiten fängt "sie" (sowohl die Bosse wie die Mitarbeiter) auch niemand auf (- wie bei uns das Sozialamt).

Auch die Sache mit den Deutschen Patenten war 1946 weitgehend geregelt.

Wenn Sie direkt auf dieser Seite gelandet sind .....

.... werfen Sie zuvor einen Blick auf diese beiden Artikel aus Dezember 1946, in denen von der ersten Vorstellung des AEG K4 Magnetophons (die HF Version) am 5.11.1946 an der Ostküste Amerikas und von der Einschätzung eines Dabeigewesenen, eines Ingenieurs von AUDIO DEVICE, berichtet wird.


audio record - 1947 - 01 (Vol.3 - No.1 January)

Das Bild könnte heißen : Schüler lernen "Radio" machen

Lernen, wie man fremde Wörter, Namen und Begriffe korrekt ausspricht


ORALEXICON is the name given to a new series of record albums, produced by NBC's Radio Recording Division in New York, seeking to standardize the pronunciation of difficult words and foreign names that are so often mispronounced on the air and in daily life. (The first edition is devoted entirely to classical music nomenclature and terminology.)

As radio's oldest and most popular announcer and commentator of classical and operatic music, Milton Cross was chosen to set up a standard of pronunciation that could be followed successfully by English speaking announcers and music lovers everywhere. Milton Cross is, therefore, the world's first ORALEXICOGRAPHER, and the ORALEXICON the first Recorded Pronouncing Dictionary for Classical Music.

The School of Radio Technique, situated in Radio City and America's oldest school devoted exclusively to radio broadcasting, designed the ORALEXICON specifically for announcers, commentators and students who have long felt the need of a pronunciation standard that could be learned easily by ear and followed with confidence.

In addition to the names of the world's most famous composers of classical and operatic music, ORALEXICON gives Milton Cross' pronunciation of: Popular Grand Operas, Contemporary Orchestral Conductors, Samples of radio continuity for Operatic and Symphonic Programs, and finally oft-used Musical Terms with exact definitions. The album consists of four 12 inch Vinylite records (8 sides), a 20 page Manual of Instructions and mimeographed copies of the continuity used.

Material Shortages and Recording Under Adverse Conditions Big Headache

By John Bubbers - Studio Engineering Supervisor - WOV - New York
(This is the fifth in a series of articles by leading figures in the recording field.)

During the war ... and it's shortages, many strange situations arose that often called for quick action. More often, "haywire" repairs had to be devised to make things function in a "normal" sort of way. Even the simplest of parts were at various times impossible to get and stocks were in some instances nearly depleted before the replacements came through.

The tube situation became critical during the latter Part of 1943 and after taking careful study of the demand, it was found, that a certain type would last only eight weeks under operating conditions.

Close analysis of the problem showed cathode leaks in all of the failures. This was attributed to insufficient removal of heat from the area surrounding the tubes. A few feet of duct work connecting to our fresh air supply from the air conditioning apparatus reduced our losses to ten percent of the original.

Problems of misaligned cutting (Schneidköpfe) heads proved to be a severe headache since time lost in their repair also had to be minimized and spacers and jigs were devised to permit their alignment by unskilled personnel. A rather strange thing occurred one hot afternoon when we were transporting an old portable cutting unit by car to a very isolated location.

Upon arriving, we found that the dampening mechanism had lost its original resiliency and would not function properly. This was rectified by locating the nearest refrigerator and cooling it down. The cutter then functioned normally.

Other precautions of supply were at first unpredictable, but as we soon learned ... our rule was "expect the worst." The quality of recording discs, fortunately, was maintained, even though the supply at times was rather limited. Looking back, our problems of the war years have taught us ingenuity and foresight and their memory is cherished only because these problems are in the past.
John Bubbers

  • Anmerkung : Es gab sie also auch, die Engpässe in der größten Volkswirtschaft der Erde, die ab 1941 gegen das schon leicht angeschlagene Deutschland in den Krieg zog. Trotz einer gigantischen Material-"Macht" gab es bei den Schlüsselindustrien durchaus dicke und ernsthafte Probleme, auf der Suche nach speziellen Fachleuten ebenfalls. Das wurde natürlich solange wie möglich "unter der Decke" gehalten.


Use of Top-Flight Talent Key to I.D.E. Success

Outstanding Public Service Recorded Programs Praised by Radio Industry

In its seven-year history the IDE (Institute for Democratic Education = Institut für demokratische Weiterbildung), a unique nonprofit organisation has produced and distributed an impressive body of transcribed radio shows which has earned it top rank with radio stations and ether critics. Devoted to the advancement of American ideals, the Institute has utilised the best professional talent-writers, actors, musicians, directors - to turn out transcriptions that have pioneered a proud path in the realm of public service programs. Each of its LEST WE FORGET series of 13 or 26 recordings, all genuine Americana, has been made available free to radio stations, bringing power-packed educational entertainment to millions of Americans.

IDE's tenth series LEST WE FORGET-THESE GREAT AMERICANS achieved unprecedented airing, afforded more than $250,000 worth of free time. Using big names to recreate dramatically the big people of our nation, the series features among others John Carradine as Woodrow Wilson, Ralph Morgan as Joseph Pulitzer, Quentin Reynolds as Wendell Willkie and Melvyn Douglas in the program on Franklin D. Roosevelt. This latter show was played by 710 stations as part of the regular series broadcast and as a memorial tribute on the first anniversary of FDR's death. (Roosevelt ist 1946 an Krebs gestorben.) The entire series has been given 1,700 hours on the air by 622 stations. In 1946 there were 7,000 individual broadcasts with many stations playing particular programs four or five times for special occasions. IDE shows were given 52% class "A" time and among the stations using them were 100 of 5,000 Watt and 10 of 50,000 Watt strength (Sendeleistung).

After radio broadcasts have been completed (mit Programmen versorgt), the Institute makes recordings available to schools through 25 distribution centers centrally spotted over the country and previous series are being circulated among 1,900 schools. During the war, the Army and OWI used the programs which also reached an international audience via short-wave.

IDE was among the first to apply successful advertising techniques to public service programs, using dramatic spot announcement to carry its democratic message.

Two new projects in the working stage at the Institute promise good listening and learning. One series, LEST WE FORGET - THE AMERICAN DREAM, dramatically probes the problems of prejudice and inter-group relations in terms of plain people - ordinary Americans whose backgrounds make them vivid story material. Employing a striking new technique of listener identification, the programs achieve a maximum of personal projection of the hearer into the situations of the average people who are the heroes of the programs.

IDE IS run by men who know the job of radio and democracy. Its Board of Governors, headed by the Dean of Boston University, Howard M. LeSourd, includes such names as Norman Corwin, Paul La;arsfeld, Lyman Bryson and Phillips Carlin. .Harold Franklin is the Institute's program director.

Acoustical Properties of Recording Studio Improved By Use of Semi-Spherical Diffusers

(From an article prepared by Forrest L. Bishop. Chief Engineer, Kasper-Gordon, Inc., for "COMMUNICATIONS")

With high-fidelity reproduction a must characteristic of all types of recording today, the studio has become a major fidelity factor. For it is in the studio that many basic problems can originate. It has thus become necessary to develop or redesign studios, that have a minimum of acoustical faults.

In our Boston studios we were faced with a problem of boominess resulting from phase distortion and reverberation. Our early analysis of the acoustical properties of the studios indicated two major factors contributed to the defect: the small room dimensions and the construction of two walls, a long wall on the control-room side and a short wall meeting the long one at right angles, both of which were surfaced with painted wallboard.

A series of test recordings were made and measurements were taken at various positions in the room with a sound level meter at frequencies from 30 to 10,000 cycles. In all measurements, high peaks appeared in varying degrees within the range of 100 to 150 cycles together with long hangovers of reverberation.

Since absorption had proved a failure, we believed that diffusion might bring about the desired effect. The conventional treatment would have been polycylindrical, but we decided to use semispherical diffusers. We believed that we would have greater control over the amount and quality of diffusion by the addition, subtraction and placement of the diffusing semispheres.

The spheres were made from a cement and cellulose mixture, easily molded to the desired size and shape. The semispherical sections ranged in size from 12 to 36 inches across. When permanently attached, they were bolted to the walls by special steel brackets. In determining the position of the diffusers, they were arranged in random pattern, more diffusers being used at the end of the studio, where less life was desired. To carry out the principle of diffusion still further, a convex pane of plexiglass was installed in the control-room window.

The resulting acoustical improvement was evident immediately. Those familiar with the studio recognized it by ear alone. The series of test recordings and measurements which followed proved that all boominess had been eliminated. Both speech and music were recorded with high-fidelity quality. Piano recordings, which formerly were made with great difficulty, could be cut with fidelity at all instrumental amplitudes. A chorus of 60 recorded in our small studio, a procedure that would have been impossible in the old studio. And the disc reproduction was excellent.

  • Anmerkung : Diesem Artikel kann man entnehmen, daß "High Fidelity" damals um 1946 und 1947 (noch) bei 10.000 Hz aufgehört hatte. Jetzt kann man sich die Überraschung der Platten-Spezialisten und der Rundfunkleute bei der November Vorführung des deutschen AEG Magnetophons noch besser vorstellen. Der normale Frequenzbereich einer (damaligen) Studio-Schallplatte ging von 80 bis etwa 7.000 Hz bei einem Rauschabstand von 40dB. Jetzt wurde aber gezeigt bzw. vorgeführt, daß die Deutschen da schon 1941 dran vorbei marschiert waren.


audio record - 1947 - 02 (Vol.3 - No.2 February)

Heute normal, damals war es etwas Besonders, Talentsuche mit Platten-Aufnahmen.

Wie eine Schallplatte länger lebt - disc-life - das sind Tips, wie man Platten besser schont,

und natürlich "Californias smallest studio" durfte nicht fehlen.

NOW, YOU TELL ONE (erzähl doch nicht ....)

Ever heard of a sponsor who cancelled his air time because his announcer had done such a good selling job that he couldn't satisfy the demands of anxious customers?

(Haben Sie jemals gehört, daß ein Auftraggeber seine Radiowerbung storniert hat, weil er den Erfolg nicht mehr handhaben konnte ?)

Well it happened. Here's how: Maurice Hart, KFWB's ultra smooth disc jockey, on his "Start the Day Right" show, played several recorded tunes, unannounced. Those listeners who guessed the correct title were to be awarded a free portrait by the sponsor, Amos Carr Photo Studios of Hollywood. Within 24 hours over 500 letters had poured into the station. At the end of the week, the rather awesome amount of 3,638 had piled up in the KFWB mail room. Mr. Carr had had enough. Expecting at the most a few hundred leads, he was forced to cancel his 1 minute spot and his offer.

Tips On Increasing Disc Life (das gilt für Lack-Folien)

By Ernest W. Franck, Research Engineer

Lacquer discs are often used to record material of sentimental or historical value, particularly personal or home recordings (Eigenaufnahmen). It is usually desirable to play these from time to time without fear that too frequent use will wear them out. With reasonable handling, lacquer discs can be played hundreds of times without any marked wearing (nennenswerte Abnutzung), but with careless handling or poor playback equipment they may be badly worn in a dozen playings.

  • Anmerkung : Das war damals schon Unsinn und ist heute bei den Vinylplatten immer noch Unsinn. Der Fachmann aus dem Schneidstudio, Herr Brüggemann, erklärte mir plausibel, daß nach dem 20. Abspielen von den Tönen über 10.000 Hz fast gar nichts mehr da ist. Jetzt hatten die 78er Platten damals noch gar keine 10.000 Hz, sondern nur maximal 7.000 Hz drauf. Doch die selbst geschnittenen Lackfolien, die "lacquer discs" waren deutlich weicher als die 78er Schellack Platten und lebten damit erheblich kürzer - bei vermeintlich voller Qualität !!

To get the greatest use from lacquer records, treat them after recording as if they were still new "blanks" (behandle die Platten, als wären es neue ungebrauchte Scheiben).

Handle them by the edges to avoid making finger marks, and keep them in envelopes or album. Remember, only one to an envelope. This prevents scratching one disc with another, and makes it easier to find the one you want. Store them standing on edge in racks or on a shelf and be sure no dust can get to them. Shelves close to the floor are bad for dust unless they are enclosed. Don't store records near a radiator.

If your turntable is velvet covered, brush out the accumulated dust with a good clothes brush or vacuum cleaner from time to time. Make it a habit to keep the lid on the machine closed when not in use. This keeps dust off the turntable. If there is no lid use a cloth cover.

See that the pick-up arm moves freely. If your pick-up is heavy, don't worry too much; you can still get hundreds of good playings from your records if you use a good playback point (eine "gesunde" Abtastnadel). With lighter pick-ups, the record life will be even longer. If your pick-up does not have a permanent point (fest eingebaute Nadel, also das wären dann Stahlnadeln), always use a new shadowgraphed needle when you play the first lacquer disc. After that, as long as you are playing lacquer discs, the steel needle (die Stahlnadel) will be good for about 30 minutes playing time, but if you play even one pressing, then change to a new needle before playing another lacquer disc.

Many people like to use sapphire playback points (eine Saphir Nadel, Diamanten waren 1946 noch nicht verfügbar). They give good results and save the worry about needlechanging. However, if you use a sapphire playback, and play a lot of pressings, keep in mind that in time (nach einiger Zeit) pressings will wear away (abnutzen) the sapphire, sometimes leaving sharp edges, which could damage the lacquer grooves.

Be on guard for a graying of the grooves (bewache die Rillen) or an accumulation of powder on the tip of the needle. Careful broadcast engineers, who use pick-ups with permanent sapphire points, never play lacquers with the same pick-up they use for pressings. This is because the pressings are likely to damage the sapphire stylus and the damaged stylus would not fit the grooves properly.

When finger marks, dust, heavy needle pressures and damaged styli are avoided, it is amasing, how a lacquer disc will stand up after many repeated playings. A little attention to these points will pay dividends - you can enjoy your records and have them too.

(eine neue Masterdisc erstellen oder zusammen-stückeln)

By Harold J. McCambridge - Supervisor of Audio Maintenance & Construction, WHOM - New York (This is the sixth in a series of articles by leading figures in the recording field)

Every recording engineer in an active broadcast or recording studio daily faces the problem of making "dubbed" or re-recorded discs, that sound "as good as, or better than" the original. This is a task, that requires all the
techniques of making an original recording (with the exception of microphone handling), plus a number of new ones that spring up, when the playback system is brought into the recording line.

Dubbing is now used so extensively in the production of commercial records that it can be considered a regular part of the production process in most of the industry. In a broadcast studio, its principal uses are as follows:

  • 1 . Preparation of transcribed program material; using recorded music from various sources for background or primary material.
  • 2. Assembly of interview-type material from spot recordings made at the convenience of the participants.
  • 3. Furnishing to clients and artists of permanent records of program material by production of copies from the original program transcription.


Obviously it is necessary to have good recording equipment in order to make a good dubbing. What is often overlooked, is that dubbing imposes very strict requirements on the playback system. From the point of view of the broadcast engineer, the most essential characteristics of a playback system for dubbing are the following:

  • 1. Harmonic distortion and especially, intermodulation distortion, must be at extremely low levels in every part of the playback system, including the pickup, equalizer, and preamplifier. A distortion level that may be tolerable in the reproduction of records can be quite unallowable in a playback system used for dubbing. The final product suffers from the distortion of three main sources added together: the original record, the playback system, and the recording system.

    The playback distortion, therefore, does not stand alone as in the reproduction of records but has a cumulative effect with that of the other elements in the dubbing system. Unless the playback system distortion is rigidly controlled the result will be a transcription with high intermodulation distortion. This is a vital matter to a broadcast engineer since an increase in intermodulation distortion is soon reflected in loss of "ear acceptability" and listener approval.

  • 2. The pickup used must cause negligible record wear, since it is often necessary to play "acetate" records many times in preparing transcribed material. An increase in surface noise or a loss of definition between the first and last playings of an original acetate are highly inconvenient, to say the least. Low record wear means, in general, that the pickup used must have high mechanical compliance, both horizontal and vertical, with the accompanying low stylus pressure. One incidental advantage of using a pickup of highly refined moving system is, that it makes possible "spot cueing" on records used for program material or dubbing, without ruining the records.

    A heavier pickup, "spotted" on a still record which is put in motion at the proper cue, will produce a minute depression in the record surface which is heard as a "tick" the next time the record is played. Records which have been spot-cued a number of times, develop so many ticks, that they are unplayable. A truly low-wear pickup does not produce an audible depression in the record surface.

  • 3. The adjustable equalizer system, necessary in every modern broadcast studio playback system, must introduce no distortion, as mentioned above, and in addition, must be stable in its characteristics and accurately calibrated. To achieve such an equalizer set-up, beginning with a pickup which itself must be equalized to produce a flat "starting" characteristic, is difficult if not impossible. By the time two or more of the commoner varieties of equalizer have been piled on top of each other, calibration is easily lost, and more important, a high level of distortion has been added to the system. These difficulties can be avoided by starting with a pickup which is inherently flat, and adding an equalizer system which has been carefully designed as a single unit, to operate with the particular pickup chosen.

    A pickup with a basic flat characteristic is highly desirable, of course, for other reasons: it produces less surface noise, and is free of the distortion characteristic of transducers which have serious peaks within the operating range, a distortion which is not removed by electrical equalization of the peaks.

Conclusion :
A satisfactory solution of the pickup problem at WHOM was finally reached after we had tested several commercial pickups. It was found that the Pickering Pickup and Equalizer for lateral playback, and the Western Electric Pickup and Equalizer for vertical playback, gave us all of the necessary dubbing characteristics. Other dubbing problems could be discussed, but it is believed that the ones outlined are those that need the most emphasis from the point of view of the broadcast engineer.

  • Anmerkung : Auch diese Technik war mit dem neuen - jetzt amerikanischen Magnetophon - ganz schnell obsolet. Und die Audio-Ingenieure hatten das nach der beeindruckenden OTS-Vorführung im November 1946 auch ganz schnell kapiert, daß man mit 60db Rauschabstands- Reserve öfter "dubben" konnte als mit 2 Schallplatten mit jeweils nur 40dB Rauschabstand.


"Space Isn't Everything In Recording" Proves Proprietor of California's Smallest Studio

What is probably one of the smallest recording studios in the world, if not the smallest, is located at 350 North Main Street in downtown Los Angeles. Owned and operated by Mr. J. T. Martin, this smallest of small studios, known as the "Hollywood Recording Studio", is the home of the "Hollywood Recording and Music Publishers".

Measuring 9' x 9' overall, Mr. Martin's workshop, strange as it may seem, is divided into individual rooms; the control room and business office, occupying a 6' x 9' portion of the precious space, and the actual recording room, operating in an area only 3' x 9' ... hardly room for half "n elbow.

Although small in structure, it has never been said, that the Hollywood Recording Studio is a small time proposition. No siree, for all the latest, up-to-the-minute recording devices are in the 9' x 9' square.

Let's look inside Mr. Martin's haven and see, what all he has packed into this king-size Corona-Corona receptacle. First of all, the recording room is equipped with 2 crystal microphones and a studio type bidirectional mike. There is also a loud speaker in this room allowing for a private playback of a finished
recording. Sometimes the loud speaker is used to carry (recorded) music from the control room to the microphones. This music is used for background for certain types of musical recordings. In the control room, we see 2 Radiotones, 1 Federal, 1 Wilcox Gay; two of these being 16" turntables.

Three loud speakers are in use. Over in one corner is a small assorted file of commercial records and a business desk. Somewhere (only heaven knows ... just where) Mr. Martin finds space for the stock of blank discs. Where do the customers stand or sit? Well, if the number of patrons exceed the space, Mr. Martin ushers them outside and they transact their business through the structure's large windows.

Hollywood Recording Studio is the third stage in Mr. Martin's rapidly growing business. Only three years ago he entered the recording field with only one 12" turntable recorder and a booth hardly big enough to hold him, the machines, a microphone and one customer. What's more, two months later he bought another machine and moved everything, lock-stock-and-barrel, into more spacious quarters; this time a 5' x 8' emporium.

And, then, after 6 months, as is always the case, there comes a time when a fellow just needs more room. So, Mr. Martin, realizing the necessity for additional space, and a great believer in the theory that good things come in small packages, shifted his belongings to his present site.

NBC Introduces New Auditioning Procedure;
Discs, Index To Talents of Radio Hopefuls

(Die Story, wie man 1947 neue Talente ausgewählt und betreut hatte.)

A file of recordings (eine Liste mit Karteikarten und Tonaufnahmen) likely to determine the future of many a young radio actor is being built up in the Radio City studios of the NBC "National Broadcasting Company" in New York - an ever-expanding index to the talents of actors and singers, who aspire to fame on the air.

  • Anmerkung: "on the air" oder "on air" bedeuten "auf Sendung" oder "live senden".

The file is the result of NBC's newly maugurated "Actor's Audition Showcase", which auditioning actors are given scripts, extensive direction and coaching and finally - backed up by sound effects and organ music for bridges in the script - a record is cut as if the show were on the air.

These sessions are held each Tuesday evening, and on Thursday afternoons NBC's national production manager, Robert K. Adams, calls the 25 directors on his staff together to hear the production of the week. The 30 minute record is played, and when the final cue has been given, the directors hold a round table discussion of the actors on the show.

Some applicants are considered good enough for parts on forthcoming productions, and others are ruled out as not yet ready for the air. The record is filed, and directors seeking a certain type of voice or character for some later production can run through a card file, get the disc for a re-play, and choose the particular type his show needs.

Before actors and actresses finally go before the mike for their recording of a program, they are interviewed and "screened" by Edward King, NBC's director of dramatic auditions. King talks to his callers, reviews their previous experience in radio, Broadw'ay shows, summer stock or college dramatics. Each is told that only the best talent will go on the air, yet every help is given youngsters, who hope to make radio their career.

After the screening, they are told to stand by for calls, and when a director takes his turn for the week's production, he studies the card files and five-minute records made of applicants' voices on "mad, sad and glad" readings. A cast is drawn to fit the script, calls are made, and the show is on its way to the disc.

"These records are among our most valuable files, and as the Actor's Audition Showcase goes on, they will become increasingly important in our casting," Mr. Adams said.

Use of Classroom-Radio Taught To Capitol Teachers

Educational Importance of Recording One of the Key Subjects in Course
(Bei uns hieß das viele Jahre später "Teach the Teacher" oder Train the Trainer)

Recently, through the cooperation of WTOP - Washington. CBS and the Washington, D. C, Public School System, a new course of study for teachers in the use of radio in the classroom was opened at "Wilson Teachers College" in
the capitol city.

  • Anmerkung : Hier wird vom deutschen Leser viel lokales Wissen verlangt bzw. vorausgesetzt. - Also : Die Capitol-Stadt ist die Hauptstadt der USA = Washington, und Washington liegt im "District Columbia", ein Mini-Staat der USA. Viele Amerikaner sagen heute noch, sie wohnten oder leben in "D.C.". Selbst ich mußte mehrfach nachfragen, wo bitte ist denn "D.C.", das kenne ich noch gar nicht und ich kannte alle 49 Staaten der USA noch aus unserem Gymnasium.

Under the directum of Miss Hazel Kenyon Markel, Director of Community Service for WTOP, the course, open to teachers and others interested in making use of radio in education, will give college credit for the weekly two-hour lectures. In a special letter to Audio Record, Miss Markel advised that since the objective of her classes was to train teachers in the effective use of radio in the classroom, recording will be taken up as a closely allied aid in this field. "The problem of transcription uses," Miss Markel said, "will be treated from the following standpoints:

  • a. Brief history of the recording field.
  • b. Advantages of recordings for the teacher.
  • c. Limitations in the use of recordings.
  • d. Available sources of information on recordings for classroom use.
  • e. Methods of effective utilization in the classroom.
  • f. Important developments in the recording and transcription field."



  • "Under 'b' (advantages)", Miss Markel continued, "will be considered the possible flexibility in use and lasting quality of recordings, the ability to preaudit the program and therefore prepare effectively for its use, the ability to repeat a program if desirable or to interrupt it for discussion by the class, and the ability to retain the program for use from time to time.
  • "Under 'c" (limitations) will be noted lack of adequate equipment in schools, the cost of such equipment, and the limited life of recordings.
  • "Under "e' (methods) for effective use will be suggested good equipment, current and good quality recordings, careful selection of the program and effective preparation for its use, close correlation with classroom work and with students' previous experiences, immediate and carefully planned follow-up procedures. The specific techniques, of course, depend on the type of program and the teacher's motives in its use, but good methods for the use of classroom aids in general apply to the use of recordings.
  • "Under 'f" (trends) we will consider late types of recording equipment, wire and film recordings, possibility of schools buying equipment with both transcription and playback facilities, teachers being trained in the use of both audio and visual aids and the possibility of transcription services for education programs."

In announcing the special course, Dr. Clyde M. Ruber, Wilson College Registrar, and also Chairman of the "Radio Committee" for the public schools of the "District of Columbia", (das ist also D.C.), stated, that it is the first direct effort to acquaint teachers of the Washington schools with the techniques of utilizing radio as an educational aid.

Dr. Hobart M. Corning, Washington's Superintendent of Schools, also urged teachers to take advantage of this opportunity for intensive study of a medium from which children get a large part of their education. "Teachers should know, how to use radio programs in their classrooms, just as they are familiar with the techniques of using visual aids such as charts and motion pictures," Dr. Corning emphasized. "Through hearing good programs in school, experiments have shown that children's out of school listening habits can be greatly improved."

audio record - 1947 - 03 fehlt


audio record - 1947 - 04 (Vol.3 - No.4) (April)

Der Präsident von Audio Devices fliegt nach Europa. Das war der event für William C. Speed. Auch für "normale" (reiche) Amerikaner, also "civilians", war ein Flug über den Atlantic ein besonderes Ereignis, da der Flug hin und zurück zudem fast so teuer war wie ein Auto.

Als der BRAUN Chefentwickler Wolfgang Hasselbach - viel später 1962 - zum ersten Male nach USA flog, kostete der PANAM (Propeller-) Flug fast 5.000.- DM, fast so viel wie ein VW-Käfer.

Dann kommt ein Bild von einer frühen Hifi-Ecke im Wohnzimmer vom Platten-Chef der Radio-Station ABC mitsamt eine sehr ausführlichen Beschreibung seiner damaligen "Hifi"-Anlage

April, 1947 - Audio Devices' President Mr. Speed visits Europe; - To Confer With Top Phono-Radio Heads

"1946 Record Sales Only Beginning - Foreign Disc Demands Up Too" - William C. Speed

William C. Speed, President of Audio Devices, Inc., sailed recently on the QUEEN ELIZABETH for Europe, where he is scheduled to meet with leading recording and broadcasting officials in England and France on market conditions and technical advancements in sound recording.

Prior to his departure, Mr. Speed related that, although 1946 witnessed the manufacture of more than 300,000,000 phonograph records, plus countless thousands of other types of transcribed recordings, the year 1947 promises even greater record production.

"We in the recording industry," Mr. Speed emphasized, "definitely believe that the popularity phonograph records and recorded radio programs enjoyed during the past year is only the beginning of a trend that will soon see more and more people enjoying recorded entertainment in their homes.

"Phonograph record production and sales alone last year," Mr. Speed pointed out, "were three times as great as before the war. This has occurred," he said, "in spite of the fact that comparatively few new phonograph machines have yet been produced. And, this large increase,"
Mr. Speed continued, "is not only seen in this country, but abroad as well. Exports of recording discs have increased rapidly and now amount to more than 10% of domestic sales. The production
of electrical transcriptions, the more expensive and better quality record, primarily used for transcribed radio programs, was also far greater than in previous years," Mr. Speed explained. Prior to 1941, this type of record was used almost entirely for musical programs.

Since that time, however, the use of completely transcribed shows has increased each year until today recorded programs are being presented approximately half of the total time radio stations are on the air.

weiter geht es in diesem Artikel :

In addition to foreseeing an unprecedented output in phonograph records and electrical transcriptions, the Audio official also explained that the demand for the instantaneous disc is now more than four-fold pre-war and with the construction of many new radio stations, coupled with the stepped-up manufacture of recording machines, the 1947 demand will reach even greater proportions.

When questioned on the practicability of other types of recording devices, such as wire and tape, and the '47 production outlook for them, Mr. Speed answered by saying: "It is our feeling in the recording industry that in the not too distant future delayed broadcasts, original motion picture recording, and conference recording will surely take advantage of some of the features offered by these other devices, particularly iron oxide coated vinyl tape. This method of recording, which was brought to a high degree of perfection by the Germans during the war, is now well along the road to mass production here. In fact, our own company has done considerable research on vinyl tape during the past year and production is now under way.

However, he concluded, "any effort to indicate that discs and oxide tape, for instance, are competitive seems rather futile at this time. Discs are still high on the wave of popularity with every indication of staying there if simplicity, quality and price are to remain as governing factors." - Our President Mr. Speed will remain in Europe for approximately one month.

"Recording Is My Avocation and Vocation Too" -
Says American Broadcasting's Recording Chief

By Larry A. Ruddell - Recording Supervisor - AMERICAN BROADCASTING COMPANY (ABC)

Ever since the day my father brought home our first "gramaphone" many years ago and said you can make music if you turn the crank and push the switch, I have been interested in making music played by other people sound good.

Since those days many changes have taken place not only in the art of recording but also in reproducing, and during this interim I have tried many ways and have had many disappointments in my quest for perfect recording and playback. Actually the nearer I have thought I was to this goal, the further away I have been from it. Recently, in my attempts to learn why, I have become surrounded in my every day life by what is actually a laboratory, consisting of the latest equipment developed in the industry.

Recording Is My ..... Ein Blick auf die Bilder

The accompanying pictures will show in part the equipment I have, and I will try and describe to the reader what my "home recording unit" consists of.

The first thing I had to do was, to sell my wife on the necessity of having it and to reconcile the investment that was necessary for the installation. Since this was to be a "proving ground" for my ideas it was essential that I have the tools with which to work, so I proceeded by "trial and error" to obtain the finest speakers, amplifiers, cutters and other components necessary for the construction of a recording and sound system.

I utilize practically every controversial component that is discussed in the trade (im Handel) today; triode and pentode amplifiers, commercial, custom built and equipment of my own design. Communication receivers, TRF and Superhet tuners, Jensen and Altec speakers, special recording equalizers, etc.

We all know that before we can hope to cut a good "platter" we have to be sure we have a good recording table, cutter and blank on which to record. If we haven't these basic requisites, regardless of what else we have, we cannot hope to obtain the desired result.

Recording Is My ..... Für die Aufnahme .....

For recording I use Allied tables. I have mounted these on twenty-four inch base panels and together with a few other "tricks" the records are free from any visible pattern and there is no discernible "rumble" on playback. For appearance sake, the overheads have been chrome-plated and the base plates are stainless steel. The control panels are mounted on bakelite and chrome trimmed. The tables are lighted with overhead lumaline fixtures.

I have tried all cutters (Schneidemaschinen) that are interchangeable with my overheads including RCA, Fairchild, Presto and others but of all these I prefer the new Presto ID.

Due to lack of space, the rack consists of 60 R-T-S jacks and the main cable from the recording table to the rack contains 50 pair of shielded leads and 10 additional pair run up from the auxiliary block in the power supply cabinet. It also contains 6 channels of equipment. Two of the amplifiers use 6B4's, one 807's, one 6L6's and two 6V6"s in the output. (Das waren die damaligen Monster-Ausgangsröhren der stärksten Endstufen.)

I use the new Super-Pro 400X for communication work, the Hallicrafter S36 for UHF work from 27.. to 143 megacycle and for comparative FM tests, a Miller TRF tuner, the new AM-FM Browning and last but not least the new deluxe Fisher.

Also in the rack, there are two fourchannel Preamps (das sind 4 getrennte Eingangskanäle, kein Quadro !!) that are interchangeable with any of the above equipment and which permit me to do all kinds of mixing; each one consists of two low-level and two high-level inputs.

I use the Western Electric 9A and 9B pickups for playback of hill-and-dale and lateral reproduction respectively. Each pickup has its own booster and pre-amp in its circuit.

There is a cutter-transfer key that makes it possible to cross-over from one cutter to the other through the same recording channel but by the use of cutter keys it is possible to record two different fifteen minute programs simultaneously.

  • Anmerkung : Die 40cm Platten (Rohlinge) konnten also 15 Minuten am Stück aufnehmen, und das ohne die spätere Rheinsche Füllschrifttechnik.

As level indicators I use the Weston VU Meter on the control panel of the recording table and on the amplifier control rack I have a DB Meter calibrated with the one on the recording table for the presetting of recording levels. All of the recording amplifiers are flat from approximately 20 to 20,000 within plus or minus 2dB with about one-half of one percent distortion.

Recording Is My ..... Die Wiedergabe .......

For the playback of commercial shellac records I use the new Garrard RC60 record changer with the new GE, MPLI crystal and the Garrard magnetic pickups, that are all interchangeable.

For recording I use discs from all of the "Big Four" manufacturers, but for overall dependability and consistency it is the Audio Red-Label two to one.

  • Anmerkung : Hier liest man, es gab also 4 große Hersteller von Lackfolien zum Schneiden von Schallplatten, also nicht nur die Firma AUDIO DEVICE.

My test equipment consists of a Hewlett-Packard Oscillator, RCA Oscilloscope, Daven Gainset, Hewlett-Packard distortion meters, RCA Volt-Ohmyst tube tester, continuity meters and miscellaneous check records. It is possible by "throwing" a patch-cord in the rack to feed tone to any channel, to "meter" the output as well as put it on the scope by the same simple procedure. I have striven for simplicity of operation and design and interchangeability of all components of the system. All input and output impedances are 500 Ohms, which greatly increases flexibility.

Always remember you cannot take out of a system more than you put in and if it is not "Clean" going in, it will not be "Clean" coming out. The human ear is final criterion by which all reproduction is judged and if it is not pleasant listening your efforts for perfect reproduction have been in vain.

"WOW" - the stability of speed

By C. J. LeBel, (Clarence Joseph Le Bel) Vice President - AUDIO DEVICES, Inc.

In the midst of the current widespread interest in improved recording fidelity, one factor has received little notice, the question of stability of speed, or wow. This is the more curious because the public is quite conscious of such a fault.

Everyone, of course, appreciates the need for watching the condition of the drive mechanism of a recording machine and playback table. On the other hand, few seem to remember the role of excessive clearance between center pin and disc hole. The result can be serious, regardless of the quality of the machine. In fact, a very fine pre-war machine can be the most erratic offender, due to pin wear from the many discs recorded or played.

The Problem
To simphfy this discussion, we disregard the spiral nature of the groove and consider the needle running at a fixed distance from the center of the disc. We ignore also, whether we are recording or reproducing - a disc miscentered in recording and played back centered will exhibit the same "wow" as a transcription disc perfectly centered in recording, and miscentered in playback. We likewise neglect the distortion products resulting from the frequency modulation process (which "wow" is), and take only the maximum range of pitch change. This figure has been the one generally discussed, being most easily measured.

If a disc with a hole larger than the center pin is placed with one edge of the hole against the pin (as usually happens in a busy recording room), the disc center is offset from the center of rotation by half the difference of hole and pin diameters, which we may call d/2. This means that the distance from the groove to the center will change, during one revolution of the disc, from R- 1/2d to R+ 1/2d, where R is the distance from the center of rotation to the groove spot which is being played.

Obviously, the proportional change in groove velocity as a result of the change in radius will be R+ 1/2d divided by R- 1/2d minus 1.

In the range of variation wc arc considering, where d is very small compared to D, this expression may be very accurately simplified to change in groove velocity = 2d/D.

This may easily be read in the following figure:


Of course, if this "wow" occurs in recording, and if the reproducing pin is the same size, the "wow" by fortuitous placement on the pin may be doubled, unchanged, or reduced to zero in reproduction.

Some Practical Observations
Obviously, some variation in disc hole size must be allowed, to allow for a reasonable amount of wear of punch and die. Also, some variation of pin size is necessary. On the other hand, the number of professional machines is limited, whereas the discs are made by the million. Hence, it is most economical to allow a larger share of the permissible variation for the disc hole.

In March 1942, the National Association of Broadcasters set the following dimensions as standard:

Disc hole .285 to .287" diameter
Pin hole .283 to .284" diameter

From the chart, these dimensions will permit a fluctuation range, at 7" diameter, of

Average .07%
Maximum .11%
Minimum .03%

These are not normally noticeable. On the other hand, we have often encountered badly worn pins on otherwise good machines, a typical case being .280"

With a .287" hole, this would produce a range of 0.2%, which may be noticeable when added to the natural wow of the machine.

Actually, the NAB limit of range of variation of recording machine speed is 0.2% (+0,1%), so it is reasonable to keep other variations small by comparison.

Wow being such a variable, and so hard to track down, it is the better part of wisdom to minimize misfit as a cause. Many machines now in use have pins as small as .278". It would be wise to measure your own machines at intervals, and if the size is beyond official limits, consult the manufacturer. Do not use an oversize pin - a hole of lower limit size may fail to fit on. With many tables in use for nine or ten years, this matter deserves real attention.

Auf der letzen Seite folgt ein Bild der Firmenprodukte 1947

auf der 1947 "National Convention" mit nachfolgendem Text:

The 1947 National Convention and Show of the "Institute of Radio Engineers" (IRE), held March 3-6 in New York's Grand Central Palace and Hotel Commodore, saw the registration of 12,500 persons and was unquestionably the most successful event in the Institute's history, IRE officials advise. During the four day meeting, 120 technical papers were presented, several of which concerned latest developments in the recording field, and 170 exhibitors from every state in the union and from every province of Canada displayed their products.

The Audio Devices display (above) showed the various types of discs, their applications, and each step necessary in their production, from raw material to finished blank. Also, the process involved in making phonograph records from Master discs. On the booth's sidcwalls, transcription labels, representing hundreds of radio stations and recording studios throughout the United States, Canada, Alaska, Porto Rico and Hawaii using Audiodiscs, were displayed.

audio record - 1947 - 05 (Vol.3 - No.5) (May)

Hier steht ein sehr langer großer Artikel über das Herstellen der Schneidfolien der eigenen Firma AUDIO DEVICE, direkt vom stellvertretenden Präsidenten Mr. C. I. LeBel.

Und auch ein Einblick auf die Rundfunklandschaft in Europa nach dem Ende des Krieges.
und darum gibt es zum ersten Mal die Zeitschrift auf 6 A4-Seiten

"Parts Show" to be held in Chicago this month

The 1947 "Radio Parts and Electronic Equipment Conference and Show" is scheduled for May 12th through May 16th 1947 at the Stevens Hotel in Chicago. Audio Devices will display its products in Booth 148.

Many Recorded Programs Being Aired By Europe's Few Commercial Stations

Discs Cut Here For Foreign Playback

European commercial radio completely inoperative during the War with the exception of some forty lowpowered stations in Spain and a high'powered (60,000 watt) privately owned station in the tiny republic of Andorra, perched high atop the Pyrenees, has now returned to normal peacetime operations. "Radio Andorra" operated commercially throughhout the entire War.

  • Anmerkung : Es steht hier kein Wort davon, daß Spanien im gesamten 2. Weltkrieg zwar "neutral" aber tendenziell deutschfreundlich war und die Deutschen darum dort nicht einmarschiert waren. Und darum blieben die dem Franco- Regime treuen Sender "am Leben". Diese "feinen geografischen Details" waren vielen Amerikanern fremd geblieben, wobei sogar Wien und Basel oft deutsche Städte waren.

The "Speakerina," Europe's famous disc jockey of Radio Andorra, who broadcasts continuous music from twelve noon until 1 A.M. each day.

After the cessation of hostilities, stations which operated commercially before the war in France were not reissued their permits to operate commercially. These stations were confiscated by the Germans at the time of the occupation and after the Liberation were taken over by the "French Provisional Government". The Government still controls them and has shown no indication that they will return them to their former owners to be operated commercially.

Today, the only radio stations operating commercially in Europe are the twenty-six stations of the Italian Network; the forty outlets in Spain; the aforementioned Radio Andorra; Radio Monte Carlo in Monaco and Radio Luxembourg. And, as is true with most stations in America today, all are making considerable use of transcribed programs in their daily schedules. The Italian network, for instance, has recently acquired an NBC Thesaurus library to supplement other recorded programs being aired to affiliates. And then too, CETRA, a subsidiary of the Broadcasting Company SIPRA, has made some excellent recordings of the best Italian opera singers. An album of Ferruccio Tagliavini made by this company is now on sale in New York City.

Radio Andorra, because of its geographic location, has practically no live talent and therefore makes constant use of recordings of every kind. As a matter of fact, this station carries on a continuous disc jockey show from twelve noon to 1 a. m., the disc jockey being a very pretty girl called "The Speakerina". Her trade mark, "Aqui Radio Andorra", is known from Gibraltar to the English Channel. This is the only station in Europe providing a continuous program of light popular music.

With a desire to sell their products in the European market, American sponsors are making recordings of their commercial programs here in America for use on the Italian network. A recent example of this was the series of singing commercials made by Elsa Miranda, the "Chicquita Banana" girl, for Royal Baking Powder, a product of Standard Brands, Inc.

The Government radio of all European countries carried on extensive experiments with recording during the war and today commercial radio is now picking up where Government radio left off. Thus, continuous and increasing use of recordings over the commercial radio stations of Europe is a certainty.

  • Anmerkung : Die Aussage bedeutet - "Mit Sicherheit (certainty) wird auch in Zukunft viel aus Musik-Konserven gesendet". Aber, wie wir wissen, hatte die Platte auf lange Sicht das Nachsehen. Das wird hier aber absichtlich nicht so genau gesagt. Denn die Hauptprodukte von Audio Device sind nämlich bislang die Schneidfolien samt Zubehör und diese Kunden darf man nicht verwirren oder unsicher machen, im Gegenteil. Das mit dem neuen Magnetophonband muß so lange wie möglich unterdrückt werden, bis AUDIO DEVICE das eigene Audio-Tape fertig hat.


Ein ganz seltener Artikel aus 1947 : Woraus besteht der Schallplatten- Schneid-Rohling - die eigentliche Lackfolie ?

Solche Artikel sind ganz selten, daß damals überhaupt einer der 4 großen Lackfolien-Hersteller mal in etwa beschrieben hatte, daß die Folien, es waren ja feste Platten mit Beschichtung, ganz besondere Eigenschaften haben mußten.


RECORDING LACQUER (Aufnehmen auf Lack-Folien)

By C. I. LeBel, Vice President AUDIO DEVICES, Inc. (Vol. 3, No. 5 May, 1947)

Lacquer forms the coating for all modern instantaneous recording discs, and since the groove is cut directly in it, the character of the coating is the character of the blank. This article answers many questions which have come to us from time to time, and so may give the professional recordist a better understanding of the material which he handles. Needless to say, a recording lacquer does not consist of a highly filtered mixture of ordinary commercial black automobile lacquer with two drops of decibel juice added to each gallon.

Virtually any lacquer made includes most, if not all, of the following classes of constituents:

Film Former (die Trägerplatte oder das Material ?)

The film forming material around which the entire formula revolves may be any one of the following: nitro-cellulose, ethyl-cellulose, acetyl-cellulose, or vinyl-chloride. All of these are available in many types and "viscosities." Complete tests leave no doubt that nitro-cellulose is by far the best as regards all professional recording qualities. Of the others, ethyl-cellulose has been utilized in some amateur home recording discs, but the results are certainly not professionally usable.

Solvents (Lösungsmittel)

The film forming material as received from its manufacturer is quite unfitted for direct coating; in fact, cannot even be applied as a film without being dissolved in a solvent, of which we have our choice of three different groups (classified by boiling point).

Low boiling solvents will evaporate very rapidly even at room temperature. Representative materials in this class are: acetone, ethyl-acetate, methyi-acetate, alcohol, methyl-ethyl-ketone, and scores of others.

Medium boilers evaporate rather slowly at room temperature, but evaporate rapidly at a slightly elevated temperature.

Finally, we have high boilers which evaporate very slowly indeed at an elevated temperature. In fact, it may be rather desirable to heat for twenty to one hundred hours to drive them out completely.

It is very difficult to make a satisfactory lacquer using only one of these solvents, so the chemist prefers to use two and often all three groups. Correct selection of solvents will greatly help production reliability.

Resin (das Harz)

Occasionally, a chemist will wish to add a resin or other similar material to give the coating some body. This will give the coating more strength, but the desirability of its use is perhaps questionable. For the chemist who insists on using such a material, there are a very large number of resins, such as the copal, dammar, mastic, shellac, and the phenolic and alkyd groups.

Diluent (der Verdünner)

To dissolve the resin or to change the evaporating properties of the solvent mixture, a diluent is very often added. Diluents do not absorb moisture and, therefore, are very well behaved in summertime, whereas some solvents previously mentioned may absorb some moisture, and this has to be driven out in the processing. On the other hand, a diluent by itself will not dissolve the film forming material, and only a limited amount of it may be used, for the limited compatibility of diluents with solvents sets a definite maximum. Representative diluents are: benzol, toluol, and naphtha.

Plasticizers (Weichmacher)

We come now to the most important materials of all, the plasticizers. Lacking them, we would find a coating which was extremely hard, extremely brittle, extremely noisy, and violently inflammable when it had dried. To prevent this, materials are added which should remain in the coating throughout life.

Properly chosen, they soften the coating, make it easy to cut and quiet in playback*. Two types of plasticizers are available: the solvent type and the nonsolvent type. Solvent plasticizers actually are solvents of extraordinarily high boiling point, so high that they very often will decompose before they will boil at atmospheric pressure. Representative materials of this sort are: dibutyl phthalate, dioctyl phthalate, triacatin, dibutyl sebacate.

Non-solvent plasticizers will not dissolve the base material, but are compatible with it. They have many excellent properties, and the only thing that limits their use is the fact that an excess will tend to sweat out under adverse conditions. It is, therefore, necessary to use a mixture of solvent and non-solvent plasticizers. Castor oil is one of the most common non-solvent plasticizers.

Dye (Farbstoff)

A black dye is usually added to a lacquer in order to improve its appearance and make it easier for the recordist to judge depth and smoothness of grooves. There are only two very simple requirements for the dye. It must be extremely dark in color, and it must be readily soluble in the solvent. There are a very large number of dyes available, all answering this description, and dye selection is perhaps the easiest problem of the entire formulation.

The Formulating Problem (überall ein großes Geheimnis)

Because Audio Devices has its own lacquer plant, the composition of the material is entirely under our own control.

An ordinary industrial finishing lacquer may contain six or seven constituents; adequate formulae may be found in many reference books and the chief limit is the cost of materials. Half of the job of an industrial lacquer chemist is the developing of the use of extenders to cheapen the material without injuring its properties, and most of the other half of this job is that of improving the quality without significantly increasing the material cost.

Recording lacquer is quite another affair. It will contain approximately thirty constituents, some of which are present to the extent only of .05% and the formulae are entirely secret.

We have never seen a single recording lacquer formula published, and the most important plasticizer constituents could not be detected with accuracy by the best analyst.

  • Anmerkung : Das war natürlich der Wissensstand von 1947, als man noch keine Spectralanalysen kannte.

The magnitude of the formulating problem may be best appreciated when we realize that it is an art as much as a science and that it is basically exeprimental in nature. The chemist must try a large number of proportions of each material with a large number of alternate proportions of each other material. We may appreciate this problem the better when we realize that fifteen materials each tested in ten different proportions will mean 15^10 tests to be made. This obviously completely impossible regardless of how many men are brought to bear on the problem. We rely very heavily then on the genius of our formulators and, as they feel their way along in the developments, they are able to eliminate a large number of the tests as obviously unnecessary.

Plasticizer Choice

As was mentioned previously, plasticizers are extraordinarily non-volatile (nicht flüchtig)materials which are used to stabilize the coating and give easy cutting, long play back life, and low flammability. There have been two "schools for formulation thought". American formulation in the American beginning period 1934-1938 used very little plasticizer; the coating was made soft by leaving a considerable amount of residual solvent. The discs were stored in a solvent tight can to retain this residual solvent. When the disc was removed from its can and left in the air, the solvent would evaporate and the coating would slowly harden.

Typical playback life for such a coating was ten to twenty playings; the noise level was high and the stability of the coating was extremely poor. Nitro-cellulose with inadequate plasticizer is not a remarkably stable material, so the groove would warp appreciably with time, and the distortion increase would be very great. We have observed a harmonic distortion increase as great as 10% to 20% within a period as short as two weeks in testing discs of this sort.

The "second school of thought" began with "La Societe des Vernis Pyrolac of Paris" in the period from 1929 to 1935. In 1938 Audio Devices entered into a contract with Pyrolac whereby AUDIO-DISCS are manufactured in the U.S.A. under an exclusive license agreement. This contract also gave all the lacquer formulation "know-how" developed by Pyrolac since 1929. Our company is thus the only American company whose experience goes back so far.

Audio Devices' success with this type of recording lacquer from 1938 on forced a change in American practice, virtually completed by 1941. Pyrolac had found that a very quiet and durable coating could be made by using adequate plasticizers of the correct proportions, and the object of their formulator was to create a coating which would have no change in character throughout life. Properly done, such a coating will have a playback life ranging from several hundred to several thousand times, 20 db lower noise level, and negligible distortion throughout life.

Plasticizers may evaporate (verdunsten, ausdünsten), oxidize, or polymerize, but because recording lacquer coatings are so sensitive, good record platsicizers will not exhibit any such changes. Ordinary industrial-lacquer data are wholly inadequate to the record-lacquer formulator's needs, for industrial lacquers can lose 50% of their plasticizing with little visible effect. 2% in recording disc plasticizing would be extremely bad.

Unser License Agreement with La Societe des Vernis Pyrolac

Audio Devices, Inc., is thus very fortunate in that its license agreement with La Societe des Vernis Pyrolac gives it access to recording lacquer tests begun as far back as 1929 and to their experience in manufacturing discs going back as far as 1932. Thanks to this extensive library of test data, our chemists have found the long life stipulation imposes no restriction whatever on the formulator's results. They were able to get quite as good performance in the long life disc as they could get if they were willing to take short cuts and use impermanent materials. It should also be pointed out, that proper plasticizers exert a very profound stabilizing effect on nitro-cellulose and that such a coating is, therefore, of longer life than we can now estimate. Pieces of plasticized nitro-cellulose made in 1866 are still in existence. Research goes on continually with noticeable results and high promise for improvements in the near future.


Every experienced recordist will testify that a given lacquer formula has a very definite personality. Some of them are treacherous, ill-mannered and prone to cause trouble, while others
are always reliable. Personality is perhaps the sum total of twelve factors.

These may be listed as follows:

  • a. Easy cutting.
  • b. Static and thread throw.
  • c. Noise (as measured immediately after cutting).
  • d. High frequency response.
  • e. Playback life.
  • f. Aging of the uncut disc, loss of cutting qualities.
  • g. Aging of the cut disc, development of noise and inter-modulation distortion.
  • h. Adherence to aluminum under all climatic conditions.
  • i. Processing characteristics, good behavior in both the silvering and gold sputtering methods.
  • j. Stability of recording properties under a wide range of temperature and humidity.
  • k. Advance ball behavior.
  • l. Grease resistance.


Coating Process (die Beschichtung der Trägerplatte)

Audio Devices introduced machine coating into this country and demonstrated that no other method equalled the single layer, homogeneous, automatic application of lacquer to an aluminum disc. When the film has dried, the disc is put through a controlled temperature cycle. This improves the coating considerably; the noise level decreases and the high frequency response improves greatly. Besides improving the coating, the temperature cycle has the important function of driving out the last remnants of the high boiling solvents. If left in, these would evaporate gradually over a period of weeks or months, and the hardness of the disc would be continually changing. When the controlled temperature cycle has been finished, the disc is punched with the standard 4-hole center, inspected and packed.

The Coating Machine

Eight years of experience have indicated that this automatic coating machine does not impose any restriction on the formulation; in short, any coating which makes a good record can be handled by this machine. Coatings made by other methods will be several db noiser than the same material applied by this machine.

Quality Control inside AUDIO DEVICE

Of course, it is one thing to devise a good formulation, and it is another thing to manufacture it successfully. This problem has become more complex year by year and, with the present deterioration of raw material, it has even become necessary to re-purify (heraus-reinigen) a large number of chemicals. The impurities removed would have no significant effect on an ordinary industrial lacquer, and it is perhaps no reflection on the chemical manufacturers to say that repurification (Endeinigung) is necessary. It has merely been found that microscopic percentages of certain impurities tend to effect considerable changes in the lacquer performance.

Quality control is not a new phrase with us, as we were using advanced quality control procedures years before the war. Production control in the disc plant is a large subject in itself; it is chemical engineering par excelsis.

*. High Frequency and Noise Level Characteristics of an Instantaneous Recording Disc - C. J. LeBel. ATE Journal, Vol. 8, No. i, p. 6, January 1941.

Reprints of This Article Available on Request

The Audio Record has been enlarged from four to six pages this month in order that we might bring our readers Mr. LeBel's complete article. Reprints are available to all who request them. Write - The Editor, Audio Record, 444 Madison Avenue, New York City.

Television Transcription in May, 1947
(Aufzeichnung von Fernsehprogrammen auf Platten)

By Will Baltin - Secretary-Treasurer - Television Broadcasters Association, Inc.

Although network facilities for television broadcasting are now being expanded across the nation, the television broadcaster will have to rely on "recorded" programs to a marked degree if he is to fulfill the requirements of the Federal Communications Commission, which initially called for a minimum of 28 hours-per-week of telecasting beginning April 1. 1947.

Networks can provide the television broadcaster in outlying regions with a certain amount of high quality programs, but for "local" shows, where sufficient talent is unavailable, he will have to fall back on transcribed or "recorded" material, much as the radio broadcaster does today.

The Disc Does The Work (Nein, das war eher ein Traum.)

Of course, in television there is a marked difference as to what constitutes a recorded show. In radio the disc jockey merely chortles his introductions - and the commercial - and then permits the disc to provide the entertainment.

Film is to television what the acetate disc is to radio. Quantitavely speaking, good film for television is scarce (Mangelware) today. (Wir schreiben Frühjahr 1947 !!!)

One can understand the reticence (Zurückhaltung, Ablehnung) of the major film producer to supply television broadcasters with the product he makes available to theatres. A great hope for the telecaster lies in the independent film producer who is presently "packaging" film shorts, ranging from one to 30 minutes in duration.

  • Anmerkung : Das war natürlich ein visionäres Wunschdenken, das sich bei uns auch nochmal 1972 bei der TED Bildplatte wiederfand, die aber auch mit Pauken und Trompeten den Bach runter gegangen war. Die analoge oder digitale Vinyl-Schallplatte war prinzipiell für die Bildaufzeichnung ungeeignet.


New Film For Recording Tele

Intriguing projects are also understood to be under way in the laboratories of du Pont and Eastman Kodak where special film is being developed for recording television programs directly off the face of a cathode ray tube. With the picture quality on the fluorescence of the kinescope constantly improving, and with the brilliance of the image easily controlled, it is quite possible to film an entire studio-produced television program off the face of the video receiving tube and thereby provide a method of not only retaining a permanent record of the production, but making possible distribution of the film for use on other stations.

  • Anmerkung : Das wurde bei uns "FAZ" genannt, die "Film-Auf-Zeichnung", der Vorläufer der MAZ, der "Magnetband-Auf-Zeichnung" ab 1956/57.

Paramount Pictures, Inc., is employing a similar method in its experiments for theatre television, and it has already been revealed that Paramount is able to receive a television program of the air, film the sight and sound, develop and print the subject in from one to three minutes. This so-called "delayed" television makes it possible to provide many theatres with a television service for immediate use when the subject is received or for exhibition whenever desired.

One thing is quite clear: There is a definite place for the "transcribed" program in television and this will be borne out to an ever-increasing extent as more video stations reach the air this year.

audio record - 1947 - 06 (Vol.3 - No.6 June)

Einen Füll-Artikel über den unbegrenzten Nutzen der Schallplattenaufnahme kann man locker übergehen.

Der Artikel über die Abnutzung von Saphiren ist dagegen interessant.

Und das Bild eines futuristischen Übertragungswagens - natürlich mit Plattenschneidmaschinen usw. - erinnert an unser ehemalig ebenfalls futuristisches deutsches HOBBY Magazin.

Dazu kommt ein sehr informativer und ausführlicher Artikel über die Funktion der amerikanischen kommerziellen Radiostationen und deren Werbefinanzierung kurz nach dem 2. Weltkrieg.

Airing of Corwfn's "One World Flight" Series - einmal um die ganze Welt - (Good Testimonial to Unlimited Value of Discs)

(Last October (1946), Norman Corwin, CBS writer-producer-director, and his assistant, Lee Bland of CBS' Documentary Unit, returned to the U. S. after a 42,000 mile air trip around-the-world; Mr. Corwin's prize as winner of the first "One World Award." During Mr. Corwin's journey he recorded his conversations with hundreds of people in many foreign lands. Upon his return, and after nearly three months of boiling this material down, Columbia broadcast a series of 13 programs. In the accompanying article, Mr. Bland tells of some of the complex recording problems encountered while the series was being prepared for the air.)

Turntable operators can best appreciate the complex recording problems of Norman Corwin's recent CBS series, "One World Flight." For the 13 broadcasts we used discs as insurance against mechanical failure and also to facilitate cueing. On each broadcast, our two turntable engineers alternated in playing the recorded excerpts. Each man had a complete set of all recorded material, generally consisting of about 30 separate cuts on double-faced 16" 33 1/3 rpm platters.

One of our main problems was to preserve the highest possible quality for the air shows. Since the engineers alternated cuts, it was therefore possible to save each man's untouched recordnigs for the dress rehearsal and broadcast by the simple expedient of switching sets of recordings after the preliminary rehearsals.

Our discs were produced at Columbia Records, from magnetic-type recordings made during the world flight. The original field recordings suffered frequently from faulty batteries picked up en route. Speed variations and quality differentials were corrected during the discing process, but only after hours of patient experimentation.

One of the most tedious aspects of the entire procedure was the job of splicing significant extracts, in the interests of time. This was accomplished manually by dexterous engineers who accepted the challenge to do the impossible and proved that the possibilities in re-recording are almost limitless.

Considering that all original field recordings were once dubbed before being piped for discing, that - in the splicing operation - we dubbed again as often as necessary, and that the ultimate blends were copied to prepare the broadcast discs, there was surprisingly little loss of quality and intelligibility. To me, this is not only a testimonial to engineering "know-how" and equipment but it gives aid and comfort to producers and directors who wish to experiment with recorded documentaries.

  • Anmerkung : Diese Weltreise machte der Autor in 1946, kurz nachdem der große Kollaps fast der gesamten Welt beendet war. Da gehörte schon eine Menge Mut und Abenteuergeist dazu.


WOR-New York's "Johnny on the Spot"

This streamlined studio on wheels will speed WOR newsmen and engineers to the scene of important newsbreaks and special events throughout the New York Metropolitan area. One of the largest mobile broadcasting studios in the country, the new unit is 27 feet long and houses a complete broadcasting studio, equipment room and driver's compartment. The 8' x 10' studio accommodates eight persons and is equipped with a full-size desk, chairs, and radio telephone to keep the unique broadcasting unit in touch with master control or the station's transmitters at Carteret, N.J. Four different short wave transmitters, as well as two fixed-studio-type recording units, two wire recorders and one spring-wound recorder are contained in the equipment room. An observation post and roof platform for news reporters, announcers and photographers will also facilitate televised special features.

  • Anmerkung : Das Bild erinnert an die futuristischen Titelbilder unseres deutschen HOBBY- Magazins der 1960er und 1970er Jahre.


THE RUBBER NETWORK (Interna über die Radio-Werbung)


  • Anmerkung vorab : Dieser Artikel gibt einen tiefen Einblick in die in den USA damals wie heute ganz normale Werbefinanzierung der großen und der ganz kleinen Radiostationen auf dem tiefen Land und derer gab es drüben ganz extrem viele. Jedes kleine Kaff hatte seinen eigenen der weit über 4000 lokalen Sender und manche dieser "Idealisten" darbten ganz schön vor sich hin.

  • "advertisers" sind die "werbetreibenden Anzeigenkunden"
  • "affiliates" sind die beteiligten Kleinst-Sendestationen
  • "advertising agency" ist die Werbeagentur

Hier also der Artikel von
B. Michael M. Sillerman, President KEYSTONE BROADCASTING SYSTEM. Inc.

We at Keystone have been given a variety of names. Since we are the only transcription network in existence, the uniqueness of our setup has apparently invited many novel appellations. In the press we are often referred to the wax web, or the wire-less network, and ever so often the "rubber network."

This name has intrigued me because in many ways it describes our operation very well. We do have a flexibility and a resilience that resembles the characteristics of rubber. This elasticity has shown itself in the transition from the pre-war period to war times and back again into post war. Our transcription mode of broadcasting has the necessary stretch in following the country's economic course. Also the need to follow the contortions of the advertiser's distribution and peculiar conditions call for a certain amount of stretching and snapping to meet the situation.

Two Hundred Sixty Affiliates

The Keystone Network, stretching from coast to coast and now consisting of 260 affiliated stations, concentrates solely on the small urban and rural areas. This is what we call BEYOND METROPOLITAN America, now often referred to as "BMA."

This emphasis on the small town is timely in view of the country's changing economy. Leading economists today state that two-thirds of the nation's retail sales are made in the small towns.

In the light of the facts and figures showing this emphasis on the small town market, the leading advertising agencies have learned that the Keystone Network has, for the first time in many decades, made it economically possible for the advertiser to buy these increasingly important markets as a unit, something they could not do before.

And the leading advertisers of the country have learned that the Keystone plan of operation makes it possible for them to promote their products via radio in these small markets on a comparable cost basis with their promotions in the large metropolitan markets.

These achievements have been accomplishcd by a simple but basic technique which finds much of its answer in the electrical transcription. The Keystone story is a success story of the transcription embellished with small station cooperation, seasoned with a firm belief in the selling power of the BEYOND- METROPOLITAN station and garnished with a realization of a tremendous aggregate market potential.

These factors all crystalized into an integrated unit, are responsible for the realization of a national coast-to-coast transcription network. It is radio's adaptation of the old adage of the small strands woven together into a strong rope. Bound together into the transcription network, the small stations are a potent selling force.

KBS Operation Explained

Many of the country's leading advertisers and agencies know from first hand experience about the modus operandi of KBS. But some people outside the orbit of Keystone ask, how does it work. The answer is quite simple. KBS is organized and operates on a network basis. However the stations are linked together by transcription instead of leased telephone wires. Keystone distributes its sustaining and commercial programs on a transcribed basis. This gives the affiliates, as well as the advertiser and agency, flexibility and freedom of movement that is essential to good programming.

Through its unique method of network operation utilizing the transcription, the commercial shows on the four major wired networks are potentially available through Keystone to the KBS affiliates. At the same time wired network advertisers can reach the BEYOND METROPOLITAN audiences by broadcasting their same wired network programs on a transcribed basis on KBS stations. Burns and Allen, and Lum'n Abner, are typical of such commercial programs. The local stations benefit by such programming and the advertisers gain a tremendous audience in the Keystone areas. Some advertisers on the other hand, have developed their own such programs for the Keystone markets exclusively. Others find the KBS sustaining features valuable commercial programs. Grove Laboratories for example, sponsored a KBS sustainer titled "Western Serenade", featuring cowboy and hillbilly talent.

Advertiser - Small Market Radio Benefit

While Keystone has evolved the transcription and its network into a bull's eye for the last frontier of American domestic commerce, it serves the advertiser and at the same time helps small market radio. Throughout its history KBS has led the fight for recognition of the transcription and the small market station. In the field of local sales every KBS transcribed sustaining program is in effect a cooperative show, since the affiliates are encouraged to sell it locally.

In all industry matters such as music copyright affairs, NAB, BMB, and general commercial program trends. Keystone is in the forefront watching all factors that have any bearing on the small market stations. The elasticity of the so-called rubber network which Keystone operates is typified by the view of the radio director of the advertising agency which leads the nation in radio billing, who states:

Hier kommen ein paar Kommentare

"KBS, through its unique method of transcription network operation makes it possible for the advertiser to buy the small markets as a unit, and at a cost that compares favorably with competitive media. Therefore Keystone has placed the national advertiser within the reach of the small market station on a nation-wide unit basis. This to my mind is the real achievement of the network."

And on the other side of the fence, the manner in which the KBS rubber network lends its stretch in support of the affiliated station is typified by the following statement of a KBS affiliate :

"Through KBS I have been able to get such programs as Lum'n Abner, Burns and Allen, Philo Vance and others on transcription. I have been able to get such national accounts on my station as Sterling Drug, Miles Laboratories, General Foods, Lever Brothers, Emerson Drug, Lucky Strike, and others. The national advertiser, I feel, has found a way - through KBS and its transcription technique - to put shows on the small stations.

"I am affiliated with KBS because I think they have done one helluva job in selling the national advertisers on small market radio. Instead of doing it with mirrors, or wires, they do it with transcriptions. They perform a function that no other group or network does in radio - they sell the small markets exclusively."

Record Collecting Habit (ein Schallplatten-Besessener)

(habit = Angewohnheit, Bessenheit, Macke, Hobby)
By Jim Walsh, Day News Editor WSLS-Roanoke, Va.

  • Anmerkung : Also, es gab sie damals 1947 auch schon, die Geschichts- Besessenen, die daran ein Interesse hatten, nicht alles zu vergessen oder in Vergessenheit geraten zu lassen.

Playing old records on my "Jim Walsh's Wax Works" program over this station comes naturally to me. Why shouldn't it? I became fascinated by the miracle of recorded music before I was three years old and can still remember the first record I ever heard. It was a comic skit called "A Night Trip to Buffalo" and it was played on an old-time talking machine with a large external morning-glory horn.

Within a few years, there was a phonograph in my home and before I was old enough to go to school I had begun making the rounds of the dealers (das sind keine Drogen-Läden, das sind ganz normale Geschäfte oder Läden) in my little town, begging the latest monthly supplement describing the new records. (I had taught myself to read.)

From that time I have never stopped collecting records - mostly by looking for them in Salvation Army depots. Good Will outlets, second-hand furniture stores and junk shops - until now I have more than 10,000 discs and cylinders, some made as long ago as 1898 and others issued only a week or so back.

Have Studied Old-Tiniers

In addition, I have made a life-long study of the careers of men and women, such as Ada Jones, Billy Murray, Henry Burr, Len Spencer and many others, who were the first recording artists, and now have a nation-wide reputation as an authority on old records. For a considerable time I have been collecting material for a book to be called "Record Makers," which will give the life stories of these old timers.

During the past five years, my monthly department, "Favorite Pioneer Recording Artists," has appeared in Hobbies Magazine, and I have also written extensively about record collecting for magazines such as the American Record Guide, This Week, Leisure, Magazine Digest and the Gramophone of London. Just before World War II, a Jap (ein Japaner) asked permission to translate some of my articles into Japanese for the benefit of the record collectors there. I don't know whether he ever got around to it!

Many of the surviving old-time recording artists, such as Billy Murray, who has been my particular hero since I was seven years old, have been my good friends of late years.

My collection contains more than 400 brands of records - most of them long since obsolete - from all parts of the world. There are many classical discs by dead or retired opera stars, but I have found for radio use it is best to restrict myself chiefly to playing old popular songs and humorous sketches. The "Wax Works", which began at WJHL in Johnson City, Tenn., in 1939 and was
also given for four years at WDBJ-Roanoke, before moving to WSLS, where I am now day news editor, has been generally popular with all classes of listeners, but its appeal seems to increase for every decade the listener has lived. Many fans have thanked me for the relief it gives them from swing and crooners.

One of the outstanding items of the collection is a record of "Shine On, Harvest Moon," sung especially for me by Jack Norworth, who collaborated with the late Nora Bayes back in 1908 in writing the song. Jack said he had been so annoyed by persons who insisted that they had Bayes and Norworth records of "Shine On. Harvest Moon," despite the fact that they never recorded it, that he appreciated more than he could say my making no such claim. In fact, he appreciated it so much that he made the record and sent it to me for a Christmas present, so I could truthfully say, I was the only person in the world with a record of "Shine On, Harvest Moon," sung by the composer !

SAPPHIRE QUALITY CONTROL (es geht um Schneidstichel)

By C. I. LeBel, Vice President of AUDIO DEVICE

In view of the widespread current discussions of the subject of quality control, it is felt that a few sidelights on this problem would be of interest to the recordist. Although American industry as a whole first fully realized the value of such programs during the war, quality control has been active at Audio Devices since the company's start. Space will permit us to touch only on cutting stylus control in this article, so disc quality control will be discussed in a later issue of Audio Record.

Stylus Properties

Two main performance characteristics of a cutting stylus are noise level and high frequency response. The interrelation of these has already been discussed in detail by the writer, so it is enough to say here, that a quieter groove may be cut, first, by increasing the length of the burnishing facet and, second, by improving the quality of the cutting of burnishing edges.

Requirements for high frequency response set a definite upper limit to the length of burnishing facet which may be employed in a professional stylus. We are left, then, only one way to keep the noise level down; that is, to control the cutting edge and burnishing surface. In doing this we are controlling an invisible detail, for the small irregularities which cause differences in noise level are so minute (sind so winzig) that they are invisible under the most powerful microscope that can be brought to bear.

  • Anmerkung : Das Elektronen Mikroskop war noch nicht erfunden.


Quality Control at Audio Device

Here at Audio Devices each sapphire is tested for noise level in a professional recording machine. Grooves are cut in lacquer discs then played back by a pickup feeding into a high gain amplifier and a standard VU meter. An 800 cycle high pass filter is used to remove the effect of turntable rumble, which because of its low frequency is virtually inaudible even though strong in meter reading. We are then measuring only the voltage produced by the record scratch. A stylus with noise level above the rejection point is sent back to the lapidary's shop for reprocessing.

  • Anmerkung : Das Filter setzt bei 800 Hz ein, sicher nicht besonders steilflankig. Das sagt aber etwas darüber aus, daß man damals 1947 die Rumpelfrequenz im 100 oder 120 Hz Bereich gefunden hatte.

  • Eine "lapidary" ist eine Schleiferei. Bei uns ist die Tätigkeit des Läppens bei den Werkzeugmachern sehr geläufig, das ist der absolute Feinschliff einer einer extrem glatten metallnen Oberfäche.

We are occassionally asked why a 100% test is necessary; why not use sampling methods? This can best be answered by a glance at test results, most conveniently shown as a number of distribution curves.

Distribution Curves

Figure 1 shows the distribution of noise levels in a batch (einer Bulk-Lieferung) of 501 points. The decibel values are meter readings, based on an arbitrary reference level.

It is interesting to note the heavily skewed shape of the curve, as well as the double peak; the statistician would correctly say that this is not statistically "normal" data. This is a typical batch of styli, for rejects are only a small percentage.

An exceedingly good batch of 511 points is shown in Figure 2. While the rejection percentage is about the same as in the previous case, the secondary peak at -59db is smaller in area, and the area under the main curve at -68db is greater.

What happens when the lapidary's laps are not in quite as good condition is typified in Figure 3, for a batch of 500 units. Note that the rejectionable percentage is several times as great and that the secondary peak has broadened considerably on the noisy side.

These styli were made by the best lapidary in the country at a time when processing was running very smoothly. Figure 4 is taken from earlier data on 605 points, and shows the result when the laps are temperamental. It is also similar to the results of an inexperienced lapidary, in that the major peak is ten to fifteen db noiser, and the rejects many more. Note that the skewness is much reduced, and the standard deviation is visibly much greater.


It is evident from this, that 100% inspection is necessary. The recordist rightfully expects all his cutting styli to be usable. Sampling inspection would guarantee that the consumer would usually have to return not over several per cent but could not assure his finding all usable. According to the laws of chance (das Gesetz des Zufalls), and since rejects run in clusters, a recordist might conceivably get three bad points in a single group of ten (i.e. 30% bad) these three being perhaps a quarter of the bad units from a batch of 500. So we must inspect all.

Sampling is primarily useful where a defect will be caught at later stages of manufacture, or where so few rejects exist that it is cheaper to find one occasionally than to test all. A good example of the latter case may be found in small composition resistors. It was found that genuinely bad units would occur once in a hundred thousand units. It was cheaper to troubleshoot every twenty thousandth assembly for a bad resistor, than to test all the hundred thousand resistors individually.

Quality Engineering

A running count of rejection percentages provides a valuable index to process quality and is sometimes the start of an engineering project. For example, see Figure 5, showing the percentage of rejects in 50 successive batches. Whereas rejections normally ran several per cent, they could run as great as 20% in irregular fashion. It was evident that, as the quality control engineer would say, the process was not under (statistical) control. We started an investigation and found that rejects in such noisy batches would often whistle, whereas whistlers were almost unheard of among the rejects of "normal" batches. After designing and building a special microscope and making hitherto difficult measurements on 500 points at a time, some correlation studies became possible.

It was soon found that two fundamental dimensions were not under statistically adequate control. Bringing them under control and computing the optimum relation, the number of out-of-control batches dropped profoundly. Thread action became more reliable, the average quality improved 10 db, and remained better. We had coordinated stylus design with lacquer coating characteristics.

After several months of good results, trouble reoccurred. A brief study showed that tool wear was causing a return to lack of control. This was easily remedied permanently and the trouble has not reoccurred since.

This is a good example of how the quaility engineer can simultaneously improve product quality and reduce product cost.

Recording's Advancement (Verbesserungen der Schneidtechnik)

By J. R. Poppele, V. P., Chief Engineer WOR - NEW YORK

As C.J. LeBel, Vice-President of Audio Devices so aptly put it: "A device (or technique) may be radically improved either by redesign, or by merely improving every part (or procedure) by as little as ten per cent."

At the WOR Recording Studios, Mr. LeBel's statement concerning improvement and re-design has been put into practice with gratifying results. New amplifiers have been installed, advanced technique having been put into practice. Recording distortion has been reduced to a minimum, and the over-all technical improvement in all types of recording has been marked.

New type recording heads are now in use. These heads are more sensitive and include temperature control. All of which produces greatly improved recordings, and this improvement has been well received by broadcast stations throughout the country, who have found an ever-increasing and wider use of transcriptions and records.

Making further advances in the art of recording, we have found that the use of improved cutting styli contourappreciably increased the signal to noise ratio in the recordings. New reproducing turntables of the latest type with direct drive and improved construction have assured rumble free, constant speed recordings.

Uniform quality has been the aim of WOR Recording Studios, and has enabled the manufacturers of popular records to offer to the public records of uniform quality and greatly improved technique.

Although the recording industry has not seen any particularly spectacular changes during the war years, there is, during the present transitional period, a continuous effort to improve here and there, and we believe we have advanced our technique are tremendously by taking advantage of new equipment as it becomes available, and by continuously striving to function as efficiently as we can.

One of the greatest advancements on an industry-wide basis was the adoption of the N.A.B. recording standards which, when considered in the light of the many other technical achievements during the past years, puts the recording industry on more solid footing than ever before. This advancement and these improvements have been reflected in the increased use of transcriptions and records by the broadcast industry, and it will be interesting to follow the improvement in the art of recording, as AM, FM and television stations increase in numbers.

Die Artikel aus 1947 sind doch länger als gedacht, darum finden Sie die 2.Hälfte auf der zweiten 1947er Seite:



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