These recording discs were made for the Brush Company “Mail-A-Voice” dictating machine. This set of 62 discs includes several slightly different types, the most significant difference being that some are paper and some are plastic. All are flexible and coated with a magnetizable powder. The Mail-A-Voice was designed by German immigrant Semi J. Begun who also used the device for personal correspondence. Several of the discs in the set are audio letters from Begun to his mother.
This “Red Head” recording-playback head was designed by Brush Company around 1950 for sale to tape recorder manufacturers. Inside the housing is a small, specially-shaped electromagnet designed to produce a focused magnetic field. When recording, a current fed into the head varied according to the strength of the input signal and that variation was captured by the recording tape. For playback, the magnetic field on the tape generated a signal in the head as it passed close. The closer the playback signal matched the input signal, the more accurate the recorded sound.
The miniaturization of electronic components has allowed designers to add features to audio products that previously would have been impractical or simply too expensive. This TEAC model A-170 cassette tape deck includes input equalizing controls more typical of studio equipment. The donor, who used this tape deck as a teenager, added the “do not touch” admonition in an effort to prevent family and friends from changing the settings.
This unusual magnetic recorder was used an a dictation machine in the 1960s. The recording medium is a letter-sized sheet coated with a magnetic powder. The round plate on the machine carried the read-write head and spins under the stationary sheet. One can then fold the recording and mail it to the recipient. The donor’s father owned a business equipment store and acquired this piece as a marketing demonstration. In this instance, the product did not succeed in the market.
The origin of magnetic recording can be traced to design work by Oberlin Smith of the United States in 1878. After seeing a demonstration of Thomas Edison’s phonograph, Smith thought about how to record sound using a magnetic medium. After ten years of failing to make a working model, Smith published his idea in the hope that someone else might benefit. Valdemar Poulsen of Denmark read Smith’s idea and in 1898 demonstrated the first practical magnetic recorder, a telephone answering machine he called a “telegraphone.” Various companies sold telegraphones for about ten years but microphone and amplification technology were not sufficiently developed to support the device. Poulsen turned to radio experiments in 1902.
The telegraphone spurred others to continue development of magnetic recording devices. Much early work took place in Germany where the telephone manufacturing firm of Ferdinand Schuchard hired engineer Semi Begun to work on circuit design. Begun became interested in magnetic recording and while working for Lorenz Company helped to design a new answering machine, the “Textophone.” Introduced in 1933, the textophone sold well since it could also be used as a dictating machine.
The Textophone consisted of two units: this telephone desk set, and a recording and playback console. The recording mechanism passed a steel wire from one reel to another in front of an electromagnet that impressed a magnetic field on the wire. When the wire was passed back in front of the electromagnet, a signal was induced in the speaker circuit. The desk set operated as a regular telephone but also includes control buttons for the recorder.
This small, portable wire recorder is an interesting example of transistorized miniaturization. The user can carry the recorder in a coat pocket while wearing the wrist-watch microphone with a connecting wire running up the sleeve. The watch does not keep time but serves solely as an unobtrusive microphone. The recorder does not use transistors but rather uses vacuum tubes. It thus requires three batteries: one for the motor drive, one for the tube filaments and one for the tube anodes.
Accessories include the wristwatch microphone, a power supply, an automobile adapter, a headset, and three patch cords. It is unclear how much noise the motor assembly made and so how useful this recorder may have been in making secret recordings. Since the tubes would have generated heat it’s also probable that the device might have been uncomfortably warm if worn. The donor’s father owned a business equipment store in Washington, D.C., and may have acquired this piece through the store. A handwritten evaluation was critical and did not recommend acquiring the product.
This front-loading Betamax video recorder was manufactured by Sony at the height of the company’s competition with producers of the rival VHS format. Beta recorders initially featured a one hour recording cassette, later lengthened to match VHS. Early Beta machines were slightly larger than early VHS units and designers struggled to put a quality audio signal on the tape without compromising video signal quality. Both formats were available for about ten years but ultimately Sony could not solve the audio-video problem without a major redesign that made newer tapes incompatible with older machines. Sony dropped the Beta format in 1988.
While telephone answering machines date to the early twentieth century, commercial units did not begin to enter the U.S. market until the 1960s. AT&T executives feared that users might cut back on telephone use if recording devices were widely adopted. The company sought to block the introduction of answering machines even while their engineers made significant technical advances in magnetic recording technology.
This model 100 “Record-O-Phone” by Robosonics was one of the early, commercially available answering machines. Introduced in 1963, these machines cost several hundred dollars each and were aimed at business customers. The unit used a reel of plastic recording tape to record incoming messages. The unit’s cradle-arms were placed beneath the handset of a desk telephone and lifted the handset off the base in response to an incoming call. Since the unit is not electrically connected to the telephone, the user avoided sanction by the telephone company.
The origin of magnetic recording can be traced to design work by Oberlin Smith of the United States in 1878. After seeing a demonstration of Thomas Edison’s phonograph, Smith thought about how to record sound using a magnetic medium. After ten years of failing to make a working model, Smith published his idea in the hope that someone else might benefit. Valdemar Poulsen of Denmark read Smith’s idea and in 1898 demonstrated the first practical magnetic recorder, a telephone answering machine he called a “telegraphone.” Various companies sold telegraphones for about ten years but microphone and amplification technology were not sufficiently developed to support the device. Poulsen turned to radio experiments in 1902.
The telegraphone spurred others to continue development of magnetic recording devices. Much early work took place in Germany where the telephone manufacturing firm of Ferdinand Schuchard hired engineer Semi Begun to work on circuit design. Begun became interested in magnetic recording and while working for Lorenz Company helped to design a new answering machine, the “Textophone.” Introduced in 1933, the textophone sold well since it could also be used as a dictating machine.
The Textophone consisted of two units: a telephone desk set, and this recording and playback console. The recording mechanism passed a steel wire from one reel to another in front of an electromagnet that impressed a magnetic field on the wire. When the wire was passed back in front of the electromagnet, a signal was induced in the speaker circuit. The desk set operated as a regular telephone but also includes control buttons for the recorder.
This Akai reel-to-reel tape recorder was imported from Japan in the late 1960s. The professional-grade recorder used transistors rather than older style vacuum tubes. That reduced power consumption and made the electronics much lighter. However, the unit features a wooden case and cover that makes it heavier than most recorders in the collection.
Japanese industrialists viewed the task of rebuilding after World War Two as an opportunity to modernize their production facilities and product lines. The transistor was one new technology in which they invested heavily.
Companies in many countries have produced magnetic recording devices, often in association with radio production. This professional grade machine was made in the 1959 by Tandbergs Radiofabrikk of Oslo, Norway. The reel-to-reel model 2TF unit was used at the National Museum to record interviews.
This Ampex model 750 recorder is a professional-grade unit. In 1927, Alexander M. Poniatoff emigrated from Russia to the United States and in 1944 founded Ampex to make equipment for the U. S. Navy. Looking for a post-war product, he attended a demonstration of a German tape recorder. Poniatoff decided that magnetic recording would be a good post-war market. Ampex concentrated on building higher-quality products for professional studio use rather than selling consumer products.
The donor purchased this unit as a graduate student for use in field work in the late 1970s. He was researching black gospel music.
This model MI-12525 RCA wire recorder shows one answer to a major problem of using steel wire to record sound. The recording wire is wound into a cartridge. The user simply inserts the cartridge into the recorder and can quickly begin using the machine. This machine was designed for use in office dictation around 1948.
Early magnetic recorders used steel wire or steel bands as a recording medium instead of plastic tape. Steel wire was fragile and tangled easily. Threading a recording machine took a certain amount of finesse and the wire could easily break if mishandled.
The Japanese emphasized electronic technology when rebuilding their manufacturing capability after World War II. The need to replace factories and equipment destroyed during the war gave them the opportunity to take advantage of the latest innovations and enter new markets. The invention of the transistor at Bell Labs in 1947 proved to be a significant opportunity for Japanese electronics companies like Minatronics.
This model TE-155 answering machine does not electrically connect to the telephone, A desk telephone was placed on the deck of the unit and the lever is slipped under the handset. When the phone rang, the lever lifted the hand-set and the recording began. This indirect method of recording was required due to AT&T’s disapproval of telephone answering machines. Since the device did not connect to the company’s lines, the user avoided sanction.
In the late 1990s Motorola introduced this Pocketalk digital answering machine. Similar to a pager in construction, the Pocketalk allowed the user to hear an incoming phone message almost anywhere. Motorola designed the unit to make use of a special transmission network to which the user paid a monthly subscription. The incoming call would be recorded at a message center, digitized and sent to the transmitter nearest the Pocketalk’s location. While the network did not have complete coverage, most metropolitan areas could receive the signals. By 2000, advances in cellular telephones made the Pocketalk obsolete.
This Phonetel model KH-141B answering machine used a removable cartridge to record telephone calls. This unit, with just a few simple controls, was imported from Hashimoto Corporation of Japan. The founder of that company, Kazuo Hashimoto, held several answering machine patents.
This model BK-416 “Soundmirror” is a modified version of Brush’s model BK-401. Like the earlier unit, the BK-416 used a paper tape coated with a magnetizable material in a reel-to-reel configuration. The retail price in 1953 was about $280, nearly $2300 in 2012 dollars. Working in parallel with Bell Laboratories and the Armour Research Foundation, Brush Development Company spearheaded American research efforts in magnetic recording prior to World War II. Building on the research of Semi Begun, the company made military wire recorders during the war and introduced consumer products like this Soundmirror after the war ended.
