, commonly known as an NAB cartridge
or simply cart
, is a 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...
Sound recording and reproduction is an electrical or mechanical inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analog recording and digital recording...
format, used for radio broadcasting for playback of material over the air such as radio commercial
Commercial radio stations make most of their revenue selling “airtime” to advertisers. Of total media expenditures, radio accounts for 6.9%. Radio advertisements or “spots” are available when a business or service provides valuable consideration, usually cash, in exchange for the station airing...
s, jingles, station identification
Station identification is the practice of radio or television stations or networks identifying themselves on air, typically by means of a call sign or brand name...
s, and music. Fidelipac is the official name of this industry standard
A de facto standard is a custom, convention, product, or system that has achieved a dominant position by public acceptance or market forces...
audio tape cartridge. It was developed in 1959 by inventor George Eash (although the invention of the Fidelipac cartridge has also been credited to Vern Nolte of the Automatic Tape Company), and commercially introduced in that same year by Collins Radio at the 1959 NAB
The National Association of Broadcasters is a trade association, workers union, and lobby group representing the interests of for-profit, over-the-air radio and television broadcasters in the United States...
Convention. The cartridge was widely used up until the late 1990s, when such formats as MiniDisc
The disc is permanently housed in a cartridge with a sliding door, similar to the casing of a 3.5" floppy disk. This shutter is opened automatically by a mechanism upon insertion. The audio discs can either be recordable or premastered. Recordable MiniDiscs use a magneto-optical system to record...
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 operator...
made the Fidelipac cartridge obsolete.
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. It was originally a 1/4 in analog recording
Analog recording is a technique used for the recording of analog signals which among many possibilities include audio frequency, analog audio and analog video information for later playback.Analog recording methods store signals as a continual wave in or on the media...
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 was 7.5 ips
The inch per second is a unit of speed or velocity. It expresses the distance in inches traveled or displaced, divided by time in seconds...
, although some cart players and recorders could be set to record at other speeds, such as 3.75 or 15 ips.
Unlike the later consumer-marketed 8-track cartridge developed later in 1964 by Bill Lear
William Powell Lear was an American inventor and businessman. He is best known for founding the Lear Jet Corporation, a manufacturer of business jets...
which had the pinch roller integrated in the cartridge, the Fidelipac cartridge had a hole in the right-hand bottom front corner of the cartridge, where the pinch roller, built-in to the player instead, would swing up into place to support the tape up against the capstan. While Collins and Gates/Harris machines had the pinch roller automatically swing up into place when the playback button was pressed, with Fidelipac and ATC (Automatic Tape Cartridge) machines, the operator had to physically push or pull a lever to get the pinch roller in place before playback could begin.
There were three sizes of Fidelipac carts available — the A
size (Fidelipac Model 300, 350 and MasterCart), the standard 8-track size cart with maximum 10-1/2 minute playing time at 7.5 ips, the B
size (Fidelipac Model 600) which was a larger cartridge designed for holding longer programs, and the even larger C
size (Fidelipac Model 1200) often used for background music applications.
The A size Fidelipac cartridge was later adapted by Earl "Madman" Muntz in 1962 for his Stereo-Pak cartridge system, 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 (3.75 ips as opposed to Fidelipac's standard 7.5 ips). Unlike the Fidelipac players which used a stationary head, the Stereo-Pak system used a moving head to go between the two programs (much like the 8-track format, which also used a moving head to access its four stereo programs).
As of 2009, the American company CartGuys
is the only remaining manufacturer of Fidelipac tapes and recorders.