The Fidelipac, commonly known as a "NAB cartridge" or simply "cart", is a
magnetic tape Magnetic tape is a medium for magnetic storage made of a thin, magnetizable coating on a long, narrow strip of plastic film. It was developed in Germany in 1928, based on the earlier magnetic wire recording from Denmark. Devices that use magn ...
sound recording Sound recording and reproduction is the electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording t ...
format, used for
radio broadcasting Radio broadcasting is transmission of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based radio st ...
for playback of material over the air such as
radio commercial In the United States, commercial radio stations make most of their revenue by selling airtime to be used for running radio advertisements. These advertisements are the result of a business or a service providing a valuable consideration, usually ...
s, jingles,
station identification Station identification (ident, network ID or channel ID or bumper) is the practice of radio and television stations and networks identifying themselves on-air, typically by means of a call sign or brand name (sometimes known, particularly in th ...
s, and music. Fidelipac is the official name of this industry standard audio tape cartridge. It was developed in 1954"Eash hand-made his own plastic cartridge for his first working unit and in 1954 began showing his unit to record people" ... "What Eash did in the Fidelipac cartridge - a term invented in 1956 by a Toledo advertising agency - was splice tape together." by inventor George Eash"The almost-square plastic-cased Fidelipac magazines, which come in three different sizes, are produced by the Fidelipac division of SAC tereophonic Automatic Corporation located in Toledo, under the direction of George Eash, inventor of Fidelipac." (although the invention of the Fidelipac cartridge has also been credited to Vern Nolte of the Automatic Tape Company "Conley Electronics Corporation, Skokie, Ill., granted a non-exclusive franchise for its Fidelipac continuous tape magazine to Collins Radio Company, Cedar Rapids, Ia. The Collins broadcasting division has incorporated the Fidelipac cartridge into its Automatic Tape Control record and playback units."), and commercially introduced in 1959 by Collins Radio Co. at the 1959 NAB Convention. The cartridge was often used at radio stations until the late 1990s, when such formats as
MiniDisc MiniDisc (MD) is an erasable magneto-optical disc-based data storage format offering a capacity of 60, 74, and later, 80 minutes of digitized audio. Sony announced the MiniDisc in September 1992 and released it in November of that year fo ...
and computerized
broadcast automation Broadcast automation incorporates the use of broadcast programming technology to automate broadcasting operations. Used either at a broadcast network, radio station or a television station, it can run a facility in the absence of a human opera ...


The Fidelipac cartridge was the first audio tape cartridge available commercially, based on the endless-loop tape cartridge design developed by Bernard Cousino in 1952, while Eash shared space in Cousino's electronics shop in the early 1950s. Instead of manufacturing the Fidelipac format himself after developing it, Eash decided to license it for manufacture to Telepro Industries, in
Cherry Hill, New Jersey Cherry Hill is a township within Camden County, in the U.S. state of New Jersey. As of the 2020 U.S. census, the township had a population of 74,553, which reflected an increase of 3,508 (+4.94%) from the 71,045 counted in the 2010 census. ...
. Telepro then manufactured and marketed the format under the Fidelipac brand name.

Tape format

Fidelipac was originally a analog recording tape, two-track format. One of the tracks was used for monaural program audio, and the other being used for a cue track to control the player, where either a ''primary'' cue tone was recorded to automatically stop the cart, a ''secondary'' tone was recorded to automatically re-cue the cart to the beginning of the cart's program material (in some models, two secondary tones, one after the program material, and one before it, were recorded to have the cart machine automatically fast-forward through any leftover blank tape at the end of a cart's program), or a ''tertiary'' tone, which was used by some players to trigger another cart player or another form of external equipment. Later versions used three tracks, two for stereo audio, and the third for the cue track. The standard tape speed for Fidelipac carts used in the radio broadcasting industry is 7.5 ips, although some cart players and recorders can be set to record at other speeds, such as 3.75 or 15 ips.Audio Engineer's Reference Book By Michael Talbot-Smith @ Googlebooks

Cartridge format

Unlike the consumer-marketed
8-track cartridge The 8-track tape (formally Stereo 8; commonly called eight-track cartridge, eight-track tape, and eight-track) is a magnetic tape sound recording technology that was popular from the mid-1960s to the early 1980s, when the compact cassette, whi ...
developed in 1964 by
Bill Lear William Powell Lear (June 26, 1902 – May 14, 1978) was an American inventor and businessman. He is best known for founding Learjet, a manufacturer of business jets. He also invented the battery eliminator for the B battery, and developed th ...
which had the pinch roller integrated into the cartridge, the Fidelipac cartridge had a hole in the right-hand bottom front corner of the cartridge, where the pinch roller built into the player would swing up into place to hold the tape against the drive capstan. While later machines from ATC, ITC, Harris, and others had the pinch roller automatically engage the cartridge when the play button was pressed (the capstan motor was already running when the cart was inserted), early machines such as Sparta, Spot-matic, and others required the operator to also push or pull a separate lever to move the pinch roller into place before playback could begin. The 8-track cartridge tape speed was slower ( ips compared to Fidelipac's ips) and did not have adequate tape support pads, and thus was not "broadcast quality." The lower speed and narrower tracks in 8-track cartridges led to higher noise and reduced frequency response. The 8-track design also lacked a cue track. There were three sizes of Fidelipac carts available — the 4-inch-wide A size (Fidelipac Model 300, 350 and MasterCart), which was a standard 8-track size cart with maximum minute playing time at 7.5 ips (this was the most common and widely used size of Fidelipac cart); the 6-inch-wide B size (Fidelipac Model 600), a larger cartridge designed for holding longer programs; and the even larger 8-inch-wide C size (Fidelipac Model 1200), often used for
background music Background music (British English: piped music) is a mode of musical performance in which the music is not intended to be a primary focus of potential listeners, but its content, character, and volume level are deliberately chosen to affect behav ...
applications like the Rowe Customusic. The A size Fidelipac cartridge was later adapted by Earl "Madman" Muntz in partnership with George Eash in 1963 for his Stereo-Pak cartridge system (also known as a 4-track cartridge), which differed in two ways — the number of tracks used (four in this case, with two played back at a time to provide a total of two programs of stereo audio), and the tape speed ( ips—the same speed as 8-track cartridges, as opposed to Fidelipac's standard ips). Unlike the Fidelipac players which used a stationary head, the Stereo-Pak system used a movable head to switch between the two programs (much like the 8-track format, which also used a movable head to select its four stereo programs).

See also

* 4-track cartridge *
8-track cartridge The 8-track tape (formally Stereo 8; commonly called eight-track cartridge, eight-track tape, and eight-track) is a magnetic tape sound recording technology that was popular from the mid-1960s to the early 1980s, when the compact cassette, whi ...


External links

History of Tape Recording

{{Audio format Audiovisual introductions in 1959 Audio storage Tape recording Discontinued media formats Broadcast engineering History of radio American inventions 1959 in music 1959 in technology Products introduced in 1959