This article deals mainly with analog tape recorders for audio applications; information on digital recording, recording of video signals, and recording of data can be found in other articles. An analog or analogue signal is any continuous signal for which the time varying feature (variable of the signal is a representation of some other Digital Audio Tape (DAT or R-DAT is a signal recording and playback medium developed by Sony in the mid 1980s PLEASE BEAR IN MIND THAT THIS IS A GENERAL ARTICLE ABOUT VCRs/VIDEOCASSETTE RECORDERS A data logger (also datalogger or data recorder) is an electronic device that records data over time or in relation to location either with a built in instrument

Reel-to-reel tape recorder.

A tape recorder, tape deck, reel-to-reel tape deck, cassette deck or tape machine is an audio storage device that records and plays back sound using magnetic tape, either wound on a reel or in a cassette, for storage. Reel-to-reel, open reel tape recording is the form of magnetic tape audio recording in which the recording medium is held on a Reel, rather than being A cassette deck is a type of Tape recorder for playing or recording audio Compact cassettes A deck was formerly distinguished from a recorder Magnetic tape is a medium for Magnetic recording generally consisting of a thin magnetizable coating on a long and narrow strip of Plastic. The Compact Cassette, often referred to as audio cassette, cassette tape, cassette, or simply tape, is a Magnetic tape sound It records a fluctuating signal by moving the tape across a tape head that polarizes the magnetic domains in the tape in proportion to the audio signal. Signal processing is the analysis interpretation and manipulation of signals Signals of interest include sound, images, biological signals such as A tape head is a type of Transducer used in Tape recorders to convert electrical signals to magnetic fluctuations and vice versa A magnetic domain describes a region within a material which has uniform Magnetization.

History

Early tape recorders were created by replacing the steel wire of a wire recorder with a thin steel tape. The first of these modified wire recorders was the Blattnerphone, created in 1929 or 1930 by the Ludwig Blattner Picture Corporation. Year 1929 ( MCMXXIX) was a Common year starting on Tuesday (link will display the full calendar of the Gregorian calendar. Year 1930 ( MCMXXX) was a Common year starting on Wednesday (link will display 1930 calendar of the Gregorian calendar. The first practical tape recorder was called K1 and demonstrated in Germany in 1935. Magnetophon was the brand or model name of the pioneering Reel-to-reel tape recorder developed by engineers of the German electronics company AEG in the 1930s based Year 1935 ( MCMXXXV) was a Common year starting on Tuesday (link will display full calendar of the Gregorian calendar. Development of magnetic tape recorders in the late 1940s and early 1950s is associated with the Brush Development Company and its licensee, Ampex; the equally important development of magnetic tape media itself was led by Minnesota Mining and Manufacturing Company (now known as 3M). The 1940s decade ran from 1940 to 1949 Events and trends The 1940s was a period between the radical 1930s and the conservative 1950s which also leads the period to be The 1950s Decade refers to the years of 1950 to 1959 inclusive Ampex ( is an American electronics company founded in 1944 by Alexander M 3M Company ( formerly Minnesota Mining and Manufacturing Company until 2002 is an American multinational conglomerate corporation with a worldwide

Further information: Magnetic tape sound recording#Early steel tape recorders

Description of operation

Electrical

A typical portable desktop cassette recorder from RadioShack. Magnetic tape has been used for Sound recording for more than 75 years RadioShack Corporation (formerly Tandy Corporation) (  is a chain of electronics retail stores in the United States, as well as parts of North America

Electric current flowing in the coils of the electromagnet causes the magnetic material on the tape to align in a manner proportional to the original signal. Electric current is the flow (movement of Electric charge. The SI unit of electric current is the Ampere. An electromagnet is a type of Magnet in which the Magnetic field is produced by the flow of an electric current. The signal can be reproduced by running the tape back across the tape head, where the reverse process occurs – the magnetic imprint on the tape induces a small current in the read head which approximates the original signal and is then amplified for playback. Faraday's law of induction describes an important basic law of electromagnetism which is involved in the working of Transformers Inductors and many forms of Many tape recorders are capable of recording and playing back at once by means of separate record and playback heads in line or combined in one unit.

Mechanical

Professional recorders usually use a simple three-motor scheme. One motor with a constant rotation speed provides traction for the leading wheel that is usually combined with a capstan and flywheel to ensure that the tape speed does not fluctuate. Capstans are rotating spindles used to move recording tape through the mechanism of a Tape recorder. A flywheel is a mechanical device with significant Moment of inertia used as a storage device for Rotational energy. The other two motors apply constant torque to maintain the tape's tension or wind the tape quickly. Cheaper models use a single motor for all required functions. There are also variants with two motors, in which one motor is used for rewinding only.

Later developments

Since their first introduction, analog tape recorders have experienced a long series of progressive developments resulting in increased sound quality, convenience, and versatility.

• Two-track and, later, multi-track heads permitted discrete recording and playback of individual sound sources, such as two stereophonic channels, or different microphones during live recording. The more versatile machines could be switched to record on some tracks while playing back others, permitting additional tracks to be "laid down" to match previously recorded material such as a rhythm track.

• Use of separate heads for recording vs. playback (three heads total, counting the erase head) enabled monitoring of the recorded signal a fraction of a second after recording. Mixing the playback signal back into the record input also created a primitive echo generator.

• Dynamic range compression during recording and expansion during playback expanded the available dynamic range and improved the signal-to-noise ratio. dbx and Dolby Laboratories introduced add-on products in this area, originally for studio use, and later in versions for the consumer market. In particular, "Dolby B" noise reduction became very common in all but the least expensive cassette tape recorders.

Solidyne GMS200 tape recorder with computer self-adjustment. Argentina 1980-1990

• Computer controlled analog tape recorders were introduced by Oscar Bonello in Argentina. ^[1] The mechanical transport used three DC motors and introduced two new advances: automated microprocessor transport control and automatic adjustment of bias and frequency response. In 30 seconds the recorder adjusted its bias for minimum THD and best frequency response to match the brand and batch of magnetic tape used. The total harmonic distortion, or THD, of a signal is a measurement of the Harmonic distortion present and is defined as the ratio of the sum of the powers The microprocessor control of transport allowed fast location of any point on the tape.

Limitations

The storage of an analogue signal on tape works well, but is not perfect. An analog or analogue signal is any continuous signal for which the time varying feature (variable of the signal is a representation of some other In particular, the granular nature of the magnetic material adds noise to the signal, which is usually heard as tape hiss. Also, the magnetic characteristics of tape are not linear. The word linear comes from the Latin word linearis, which means created by lines. They exhibit a characteristic hysteresis curve, which causes unwanted distortion of the signal. A system with hysteresis can be summarised as a system that may be in any number of states independent of the inputs to the system A distortion is the alteration of the original shape (or other characteristic of an object image sound waveform or other form of information or representation Some of this distortion is overcome by using an inaudible high-frequency AC bias signal when recording, though the amount of bias needs careful adjustment for best results. Tape bias is the term for two phenomena DC bias and AC bias, that improve the fidelity of analogue Magnetic tape sound recordings DC bias is the addition Different tape material requires differing amounts of bias, which is why most recorders have a switch to select this (or, in a cassette recorder, switch automatically based on cutouts in the cassette shell). Additionally, systems such as Dolby B, Dolby C and Dolby HX-Pro have been devised to ameliorate some of the noise and distortion problems. Dolby NR is the name given to a series of noise reduction systems developed by Dolby Laboratories for use in analogue Magnetic tape recording Variations in tape speed cause flutter, which can be reduced by using dual capstans. Higher speeds used in professional recorders are prone to cause "head bumps," which are fluctuations in low-frequency response.

Variety of tape recorders

There are a wide variety of tape recorders in existence, from small hand-held devices to large multitrack machines. Multitrack recording ('multitracking' or just 'tracking' for short is a method of Sound recording that allows for the separate recording of multiple sound sources to create A machine with built-in speakers and audio power amplification to drive them is usually called a "tape recorder" or – if it has no record functionality – a "tape player," while one that requires external amplification for playback is usually called a "tape deck" (regardless of whether it can record).

Multitrack technology enabled the development of modern art music and one such artist, Brian Eno, described the tape recorder as "an automatic musical collage device". Art music (or serious music or erudite music) as defined by Jacques Siron is an umbrella term generally used to refer to musical traditions implying advanced structural Brian Peter George St John le Baptiste de la Salle Eno (born 15 May 1948 commonly known as Brian Eno (ˈiːnoʊ is an English Musician, producer

Use of tape recorders

An important use of tape recorders is the recording of video. Video cassette recorders differ substantially from audio recorders due to the use of a rotating magnetic head that uses a helical scan over the tape medium. PLEASE BEAR IN MIND THAT THIS IS A GENERAL ARTICLE ABOUT VCRs/VIDEOCASSETTE RECORDERS Helical scan is a method of recording high bandwidth signals onto Magnetic tape. Helical scans increase the relative speed of the tape surface over the head.

While they are primarily used for sound recording, tape machines were also important for data storage before the advent of floppy disks and CDs, and are still used today, although primarily to provide an offline backup to hard disk drives. A floppy disk is an increasingly Obsolete data storage medium that is composed of a disk of thin flexible ("floppy" Magnetic storage medium encased A Compact Disc (also known as a CD) is an Optical disc used to store digital data, originally developed for storing digital audio

Tapedeck speeds

There are many different tape speeds which are in use in all sorts of tape recorders. Most often these speeds appear on tapedecks. But – while meaning the same speed – many tapedecks are either in centimeters per second (cm/s) or in inches per second (in/s). A centimetre ( American spelling: centimeter, symbol cm) is a unit of Length in the Metric system, equal to one hundredth The second ( SI symbol s) sometimes abbreviated sec, is the name of a unit of Time, and is the International System of Units The inch per second is a unit of Speed or Velocity. It expresses the Distance in Inches ( in) traveled or displaced divided

To overcome this, here is an overview:

References

See also: tape formats

• 8 track tape
• Cassette deck
• Elcaset
• Compact audio cassette
• Reel-to-reel audio tape recording
• Wire recording
• Helical scan
• Digital Audio Tape (DAT)

See also

• Audio editing
• Audio format
• Electromagnetism
• Electronic music
• Sound recording
• Wire recording

External Links

• Tape Recorder - Interactive Java Tutorial National High Magnetic Field Laboratory
• WikiRecording's Guide to Analog Tape