VX (videocassette format)
Encyclopedia
VX was a short-lived and unsuccessful consumer analog recording
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...

 videocassette format developed by Panasonic
Panasonic
Panasonic is an international brand name for Japanese electric products manufacturer Panasonic Corporation, which was formerly known as Matsushita Electric Industrial Co., Ltd...

 and launched in 1975 in Japan. In the US it was sold using the Quasar
Quasar (brand)
Quasar is a North American brand of electronics, first used by Motorola in 1967 for a model line of transistorized color televisions. These televisions were well-known for containing all serviceable parts in a drawer beneath the television's cabinet...

 brand and marketed under the name "The Great Time Machine" to exhibit its time-shifting capabilities, since VX machines had a companion electro-mechanical clock timer for timed recording of television program
Television program
A television program , also called television show, is a segment of content which is intended to be broadcast on television. It may be a one-time production or part of a periodically recurring series...

s. In Japan, the VX-100 model was launched in 1975, with the VX-2000 following in 1976. The first and only model sold in North America was the Quasar VR-1000 (based on the Panasonic VX-2000), with the VT-100 timer.

Design

The VX cassette itself had both reels of 1/2 in 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...

 stacked on top of each other in a coaxial fashion (much like the earlier Philips
Philips
Koninklijke Philips Electronics N.V. , more commonly known as Philips, is a multinational Dutch electronics company....

 "VCR
Video Cassette Recording
Video Cassette Recording was an early domestic analog recording format designed by Philips. It was the first successful consumer-level home videocassette recorder system. Later variants included the VCR-LP and Super Video formats.The VCR format was introduced in 1972, just after the Sony...

" and Cartrivision
Cartrivision
Cartrivision was an analog video videocassette format introduced in 1972, and the first format to offer feature films for consumer rental. It was produced by Frank Stanton's Cartridge Television, Inc. , a subsidiary of Avco, who also owned Embassy Pictures at the time. Cartrivision was available in...

 formats) in the bottom half of the tape, with a circular opening on the underside of the top half of the cassette, where the video head drum would enter. The tape in this opening was pre-formed in a loop to go around the head drum, eliminating the need for the tape to be pulled out of the cassette and threaded around the drum (like later videocassette formats like VHS
VHS
The Video Home System is a consumer-level analog recording videocassette standard developed by Victor Company of Japan ....

 and Betamax
Betamax
Betamax was a consumer-level analog videocassette magnetic tape recording format developed by Sony, released on May 10, 1975. The cassettes contain -wide videotape in a design similar to the earlier, professional wide, U-matic format...

). The opening was protected by a cylindrical plastic plug to protect the tape, which was unscrewed from the opening when the tape was loaded in the machine (by means of moving a horizontal lever on the front of the machine), and inserted back into the tape when ejected (by moving the lever back).

The video head drum itself of a VX machine also has the unique distinction of being completely removable and replaceable without any special tools or equipment. The drum has a knurled nut on top, which can be loosened (and tightened) by hand, allowing the drum to be removed from the deck for cleaning or replacement. To this date, the VX machines have been the only VCR designed with this feature.

Specifications

  • Recording method: Single head, alpha wrap helical scan
    Helical scan
    Helical scan is a method of recording high bandwidth signals onto magnetic tape. It is used in reel-to-reel video tape recorders, video cassette recorders, digital audio tape recorders, and some computer tape drives....

  • Head drum diameter: 48mm
  • Cassette dimensions: 213×146×44mm (550 g)
  • Tape width: ½ inch (12.65 mm)
  • Tape speed: 52.133 mm/s
  • Video track width: 48 μm (73 μm with guard band)
  • Relative velocity: 9.091 m/s
  • Video signal: Frequency modulation 3.3-4.6 MHz (chroma signal: Color-under
    Heterodyne
    Heterodyning is a radio signal processing technique invented in 1901 by Canadian inventor-engineer Reginald Fessenden where high frequency signals are converted to lower frequencies by combining two frequencies. Heterodyning is useful for frequency shifting information of interest into a useful...

    688.374 kHz)
  • Audio signal: 1 channel linear track (0.4 mm)
  • Recording time: Originally up to 100 minutes, 120 minute cassettes became available at a later date

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK