Wire recording
Encyclopedia
Analog signal
An analog or analogue signal is any continuous signal for which the time varying feature of the signal is a representation of some other time varying quantity, i.e., analogous to another time varying signal. It differs from a digital signal in terms of small fluctuations in the signal which are...
audio storage in which a magnetic recording is made on thin steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
or stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....
wire
Wire
A wire is a single, usually cylindrical, flexible strand or rod of metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Standard sizes are determined by various...
.
The wire is pulled rapidly across a recording head
Tape head
A tape head is a type of transducer used in tape recorders to convert electrical signals to magnetic fluctuations and vice versa.-Principles of operation:...
which magnetizes each point along the wire in accordance with the intensity and polarity of the electrical audio signal
Audio signal
An audio signal is an analog representation of sound, typically as an electrical voltage. Audio signals may be synthesized directly, or may originate at a transducer such as a microphone, musical instrument pickup, phonograph cartridge, or tape head. Loudspeakers or headphones convert an electrical...
being supplied to the recording head at that instant. By later drawing the wire across the same or a similar head while the head is not being supplied with an electrical signal, the varying magnetic field presented by the passing wire induces a similarly varying electric current in the head, recreating the original signal at a reduced level.
Magnetic wire recording was replaced by magnetic tape
Magnetic tape
Magnetic tape is a medium for magnetic recording, made of a thin magnetizable coating on a long, narrow strip of plastic. It was developed in Germany, based on magnetic wire recording. Devices that record and play back audio and video using magnetic tape are tape recorders and video tape recorders...
recording, but devices employing one or the other of these media had been more or less simultaneously under development for many years before either came into widespread use. The principles and electronics involved are nearly identical. Wire recording initially had the advantage that the recording medium itself was already fully developed, while tape recording was held back by the need to improve the materials and methods used to manufacture the tape.
History
The first wire recorder was a Valdemar PoulsenValdemar Poulsen
Valdemar Poulsen was a Danish engineer who developed a magnetic wire recorder in 1899.-Biography:He was born on 23 November 1869 in Copenhagen...
Telegraphone of the late 1890s. Wire recorders for dictation and telephone recording were made almost continuously by various companies (mainly the American Telegraphone Company) through the 1920s and 1930s, but use of this new technology was extremely limited. Dictaphone
Dictaphone
Dictaphone was an American company, a producer of dictation machines—sound recording devices most commonly used to record speech for later playback or to be typed into print. The name "Dictaphone" is a trademark, but in some places it has also become a common way to refer to all such devices, and...
and Ediphone recorders, which still employed wax cylinders as the recording medium, were the devices normally used for these applications during this period.
The brief heyday of wire recording lasted from approximately 1946 to 1954. It resulted from technical improvements and the development of inexpensive designs licensed internationally by the Brush Development Company of Cleveland, Ohio and the Armour Research Foundation of the Armour Institute of Technology (later the Illinois Institute of Technology
Illinois Institute of Technology
Illinois Institute of Technology, commonly called Illinois Tech or IIT, is a private Ph.D.-granting university located in Chicago, Illinois, with programs in engineering, science, psychology, architecture, business, communications, industrial technology, information technology, design, and law...
). These two organizations licensed dozens of manufacturers in the U.S., Japan, and Europe.
These improved wire recorders were not only marketed for office use, but also as home entertainment devices that offered advantages over the home disc recorders
Acetate disc
An acetate disc, also known as a test acetate, dubplate , lacquer , transcription disc or instantaneous disc...
which were becoming increasingly popular for making short recordings of family and friends and for recording excerpts from radio broadcasts. Unlike home-cut phonograph records, which could accommodate only a few minutes of audio on each side, the steel wire could be repeatedly re-recorded and allowed much longer uninterrupted recordings to be made.
The earliest magnetic tape recorders, not commercially available in the U.S. until 1948, were too expensive, complicated and bulky to compete with these consumer-level wire recorders. During the first half of the 1950s, however, tape recorders which were sufficiently affordable, simple and compact to be suitable for home and office use started appearing and they rapidly drove wire recorders from the market.
Exceptionally, the use of wire for sound recording continued into the 1960s in Protona's Minifon miniature recorders, in which the importance of maximizing recording time in a minimum of space outweighed other considerations. For any given level of audio quality, the nearly hair-thin wire had the advantage that it was a much more compact storage medium than tape. The Minifon wire recorder was designed for stealth use and its accessories included a microphone disguised as a wristwatch.
Wire recording was also used in some aircraft cockpit voice recorder
Cockpit voice recorder
A cockpit voice recorder , often referred to as a "black box", is a flight recorder used to record the audio environment in the flight deck of an aircraft for the purpose of investigation of accidents and incidents...
s and flight data recorder
Flight data recorder
A flight data recorder is an electronic device employed to record any instructions sent to any electronic systems on an aircraft. It is a device used to record specific aircraft performance parameters...
s beginning in the early 1940s, mainly for recording radio conversations between crewmen or with ground stations. Because steel wire was more compact, robust and heat-resistant than plastic-based magnetic tape, wire recorders continued to be manufactured for this purpose through the 1950s and remained in use somewhat later than that. There were also wire recorders made to record data in satellite
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
s and other unmanned spacecraft
Robotic spacecraft
A robotic spacecraft is a spacecraft with no humans on board, that is usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to...
of the 1950s to perhaps the 1970s.
Magnetic format
Poulsen's original telegraphone and indeed all very early recorders placed the two poles of the record/replay head on opposite sides of the wire. The wire was thus magnetised transversely to the direction of travel. This method of magnetization was quickly found to have the limitation that as the wire twisted during playback, there were times when the magnetization of the wire was at right angles to the position of the two poles of the head and the output from the head fell to almost zero.The development was to place the two poles on the same side of the wire so that the wire was magnetised along its length or longitudinally. Additionally, the poles were shaped into a "V" so that the head wrapped around the wire to some extent. This increased the magnetising effect and also increased the sensitivity of the head on replay because it "collected" more of the magnetic flux from the wire. This system was not entirely immune to twisting but the effects were far less marked.
The longitudinal method survives into magnetic tape recording to this day.
Media capacity and speed
Compared to tape recorders, wire recording devices had a high media speed, made necessary because of the use of the solid metal medium. Standard postwar wire recorders used a nominal speed of 24 inches per second (610 mm/s), making a typical one-hour spool of wire 7,200 feet (approx. 2200 m) long. This enormous length was possible on a spool less than 3 inches in diameter because the wire was nearly as fine as hair. 30 and 15 minute lengths of wire were also available on these small spools, which were employed by the majority of recorders made after 1945. Some heavy-duty recorders used the larger Armour spools, which could contain enough wire to record continuously for several hours. Because the wire was pulled past the head by the take-up spool, the actual wire speed slowly increased as the effective diameter of the take-up spool increased. Standardization prevented this peculiarity from having any impact on the playback of a spool recorded on a different machine, but audible consequences could result from substantially altering the original length of a recorded wire by excisions or by dividing it up onto multiple spools.Handling and editing
To facilitate handling as the user threaded the wire across the recording head and affixed it to the take-up spool, some manufacturers attached a strip of plastic to each end of the wire. This was designed to press-fit snugly into either spool. To prevent the wire from piling up unevenly on the spool as it was recorded, played or rewound, on the majority of machines the head assembly slowly oscillated up and down (or back and forth) to distribute the wire evenly. On some machines, moving wire guides performed this function, like the mechanism that distributes line across a fishing reelFishing reel
A fishing reel is a "cylindrical device attached to a fishing rod used in winding the line". Modern fishing reels usually have fittings which make it easier to retrieve the line and deploy it for better accuracy or distance. Fishing reels are traditionally used in the recreational sport of angling...
. After recording or playback, the wire had to be rewound before any further use could be made of the machine—unlike tape recorders, the take-up reel on most wire recorders was not removable.
A break in the wire was repaired by tying the ends together and trimming. When such a repair was made to an existing recording a jump in the sound would result during playback, but because of the high speed of the wire the loss of an inch due to tying and trimming was trivial and might pass unnoticed. Unfortunately, if the wire broke it could easily become tangled and snarls were extremely difficult to fix. Sometimes the only practical solution was to carefully cut the tangled portion away from the spool—an operation which ran the risk of endlessly enlarging the problem—and discard it. The difficulty of handling the wire itself when necessary was arguably the only serious shortcoming, among several definite advantages, of steel wire as a monophonic recording medium.
Editing was accomplished by cutting and splicing. As the knot of each splice passed through the head during playback, a very brief loss of normal contact was inevitable and the resulting dropouts could make editing musical recordings problematic. Although wire was not as suitable for editing as plastic-based magnetic tape would prove to be, in the field of radio broadcasting it offered tremendous advantages over trying to edit material recorded on transcription discs, which was usually accomplished by dubbing to a new transcription disc with the aid of multiple turntables, stopwatches and a lot of patience. The first regularly scheduled network radio program produced and edited on wire was CBS
CBS
CBS Broadcasting Inc. is a major US commercial broadcasting television network, which started as a radio network. The name is derived from the initials of the network's former name, Columbia Broadcasting System. The network is sometimes referred to as the "Eye Network" in reference to the shape of...
' Hear It Now
Hear It Now
Hear It Now, an American radio program on CBS, began in December 1950, ending in June 1951. It was hosted by Edward R. Murrow and produced by Murrow and Fred W. Friendly. It ran for one hour on Fridays at 9 pm Eastern Time.- The show's beginnings :...
with Edward R. Murrow
Edward R. Murrow
Edward Roscoe Murrow, KBE was an American broadcast journalist. He first came to prominence with a series of radio news broadcasts during World War II, which were followed by millions of listeners in the United States and Canada.Fellow journalists Eric Sevareid, Ed Bliss, and Alexander Kendrick...
.
Fidelity
The audio fidelityFidelity
"Fidelity" is the quality of being faithful or loyal. Its original meaning regarded duty to a lord or a king, in a broader sense than the related concept of fealty. Both derive from the Latin word fidēlis, meaning "faithful or loyal"....
of a wire recording made on one of these post-1945 machines was comparable to a contemporary phonograph record or one of the early tape recorders, given a microphone or other signal source of equal quality. Because of its homogeneous nature and very high speed, wire was relatively free of the noticeable background hiss which characterized tape recordings before the advent of noise reduction systems. The Magnecord Corp. of Chicago briefly manufactured a high-fidelity wire recorder intended for studio use, but soon abandoned the system to concentrate on tape recorders.
Notable uses
In 1944-1945, the 3132 Signal Service Company Special of the U.S. ArmyUnited States Army
The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...
's top secret Ghost Army used wire recorders to create sonic deception on the Western Front
Western Front (World War II)
The Western Front of the European Theatre of World War II encompassed, Denmark, Norway, Luxembourg, Belgium, the Netherlands, France, and West Germany. The Western Front was marked by two phases of large-scale ground combat operations...
in the Second World War
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. Multiple battlefield scenarios were recreated using military sounds recorded at Fort Knox
Fort Knox
Fort Knox is a United States Army post in Kentucky south of Louisville and north of Elizabethtown. The base covers parts of Bullitt, Hardin, and Meade counties. It currently holds the Army Human Resources Center of Excellence to include the Army Human Resources Command, United States Army Cadet...
, Kentucky
Kentucky
The Commonwealth of Kentucky is a state located in the East Central United States of America. As classified by the United States Census Bureau, Kentucky is a Southern state, more specifically in the East South Central region. Kentucky is one of four U.S. states constituted as a commonwealth...
. The wire-recorded audio, which was played back through powerful amplifiers and speakers mounted on vehicles, was used to conceal real Allied
Allies of World War II
The Allies of World War II were the countries that opposed the Axis powers during the Second World War . Former Axis states contributing to the Allied victory are not considered Allied states...
deployments, locations and operations.
In 1944 at the Middle East Radio Station of Cairo, Egyptian composer Halim El-Dabh
Halim El-Dabh
Halim Abdul Messieh El-Dabh is an Egyptian-born American composer, performer, ethnomusicologist, and educator, who has had a career spanning six decades...
used wire recorders as a tool to compose music.
In 1946 David Boder, a professor of psychology at Illinois Institute of Technology in Chicago, traveled to Europe to record long interviews with "displaced persons"—most of them Holocaust
The Holocaust
The Holocaust , also known as the Shoah , was the genocide of approximately six million European Jews and millions of others during World War II, a programme of systematic state-sponsored murder by Nazi...
survivors. Using an early wire recorder from the Armour Research Foundation, Boder came back with the first recorded Holocaust testimonials and in all likelihood the first recorded oral histories of significant length.
In 1946, Norman Corwin
Norman Corwin
Norman Lewis Corwin was an American writer, screenwriter, producer, essayist and teacher of journalism and writing...
and his technical assistant, Lee Bland, took a wire recorder on their One World Flight, a round-the-world trip subsidized by friends of Wendell Wilkie and patterned after Willke's own 1942 trip. Corwin documented the post-war world and used his recordings in a series of 13 broadcast documentaries on CBS—which were also among the first broadcast uses of recorded sound allowed by the radio networks.
In 1949 at Fuld Hall in Rutgers University
Rutgers University
Rutgers, The State University of New Jersey , is the largest institution for higher education in New Jersey, United States. It was originally chartered as Queen's College in 1766. It is the eighth-oldest college in the United States and one of the nine Colonial colleges founded before the American...
, Paul Braverman made a 75-minute recording of a Woody Guthrie
Woody Guthrie
Woodrow Wilson "Woody" Guthrie is best known as an American singer-songwriter and folk musician, whose musical legacy includes hundreds of political, traditional and children's songs, ballads and improvised works. He frequently performed with the slogan This Machine Kills Fascists displayed on his...
concert using a wire recorder. The recording only came to light in 2001, and appears to be the only surviving live recording of Woody Guthrie; it was restored over several years and released on CD in 2007. The CD, The Live Wire: Woody Guthrie in Performance 1949, subsequently won the 2008 Grammy Award for Best Historical Album
Grammy Award for Best Historical Album
The Grammy Award for Best Historical Album has been presented since 1979. During this time the award had several minor name changes:*In 1979 the award was known as Best Historical Repackage Album*In 1980 it was awarded as Best Historical Reissue...
.
In 1952, the Harvard University
Harvard University
Harvard University is a private Ivy League university located in Cambridge, Massachusetts, United States, established in 1636 by the Massachusetts legislature. Harvard is the oldest institution of higher learning in the United States and the first corporation chartered in the country...
physics department's musical variety show The Physical Revue, written and performed by Tom Lehrer
Tom Lehrer
Thomas Andrew "Tom" Lehrer is an American singer-songwriter, satirist, pianist, mathematician and polymath. He has lectured on mathematics and musical theater...
, was recorded on wire; this recording was recently rediscovered and made available online.
Wire recorders sometimes appear in motion pictures made during the time of their widest use. For example, in office scenes in the original 1951 version of The Thing
The Thing from Another World
The Thing from Another World , is a 1951 science fiction film based on the 1938 novella "Who Goes There?" by John W. Campbell . It tells the story of an Air Force crew and scientists at a remote Arctic research outpost who fight a malevolent plant-based alien being...
, a typical Webster-Chicago
Webster-Chicago
For the contractor based in San Mateo, California, see Webcor BuildersThe Webster Chicago Corporation was a maker of electronic equipment in Chicago Illinois. The product line included record changers, wire recorders and reel to reel tape recorders. They also made phonograph amplifiers that are...
unit is plainly visible on a small table by the window. In some shots (e.g., at 0:11:40 on the 2003 DVD release), its detached lid, carrying two extra spools of wire, is also visible. In this instance the recorder is simply "set dressing" and is not shown in operation.
Though fictional, the Allied officers of Hogan's Heroes
Hogan's Heroes
Hogan's Heroes is an American television sitcom that ran for 168 episodes from September 17, 1965, to March 28, 1971, on the CBS network. The show was set in a German prisoner of war camp during the Second World War. Bob Crane had the starring role as Colonel Robert E...
used a wire recorder to record a meeting in Kommandant Klink's office on a device that was disguised as a sewing box made of wooden thread spools.
See also
- Webster-ChicagoWebster-ChicagoFor the contractor based in San Mateo, California, see Webcor BuildersThe Webster Chicago Corporation was a maker of electronic equipment in Chicago Illinois. The product line included record changers, wire recorders and reel to reel tape recorders. They also made phonograph amplifiers that are...
, manufacturer of Webster-Chicago and WebCor wire-recorders - Sound recording
- Tape recorderTape recorderAn audio tape recorder, tape deck, reel-to-reel tape deck, cassette deck or tape machine is an audio storage device that records and plays back sounds, including articulated voices, usually using magnetic tape, either wound on a reel or in a cassette, for storage...