Parts Express - Tech Terms Glossary

Tech Terms Glossary

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Tap: used to split off a portion of the original signal for use elsewhere.

Tearing: A picture condition in which horizontal lines are displaced in an irregular manner.

Telemetry: A system utilizing control code transmitters and receivers. They can use either video cable or a simple twisted pair cable to send their information.

Termination: A non-inductive resistor that has the same resistance as the characteristic of the cable being used.

TFT (Thin Film Transistor) Active Matrix LCD Color Display: An LCD screen in which each pixel is powered by its own transistor, for images with purer, more distinct color and higher contrast ratio.

Timebase Corrector (T.B.C.): An electronic circuit that aligns unsynchronized video signals before signal processing. Used in multiplexers and quad splatters.

Tone Arm: Device that holds the phono-cartridge, applies the necessary tracking force for tracing the grooves of the record.

Tracking: A zoom lens' ability to remain in focus during the entire zoom range from wide angle to telephoto position.

Tracking Force: Weight or force pushing the stylus down into the record groove.

T-S: Thiele-Small parameters, a certain collection of loudspeaker specifications named after the scientists who developed them.

24K Gold-Plating: Gold plating prevents oxidation of the plug's surface, minimizing the contact resistance and transmission loss that occurs over time.

UHF (Ultra-High Frequency): regulated band of frequencies used for broadcast signals. Used for TV (channels 14-63), two-way radios, wireless communications, instruments and other similar equipment.

Vap: The volume of air having the same resistance to movement as the suspension of a passive radiator.

Vas: The volume of air having the same compliance, or ease of movement, as the suspension (surround, spider, etc.) of a speaker driver, i.e. a driver with a loose suspension will have a higher compliance and low Vas.

Vb: The internal volume of a vented speaker cabinet.

Vc: The internal volume of a sealed speaker cabinet.

VCP (Video Cassette Player): Component that plays back pre-recorded VCR tapes.

VCR (Video Cassette Recorder): Component that records and plays back RF signals used for TV and CATV broadcast.

Vertical Retrace: The return of the electron beam to the top of a television picture tube screen or a camera pickup device target at the completion of the field scan.

VHF (Very-High Frequency): regulated band of frequencies used for broadcast signals. Used for TV (channels 2-13), two-way radios, wireless communications, instruments and other similar equipment.

VHS (Video Home System): Probably the most popular format of home video tape equipment.

VHS Hi-Fi Stereo Audio: An audio recording and playback technology utilized in many VHS VCRs that delivers near CD-quality sound. Through a "depth multiplexing" technique, the audio signal is laid down beneath the video signal along the width of the tape instead of in a narrow band at the edge. This allows for inclusion of much more signal information, as well as the Dolby Surround sound encoding found on all major video movie releases.

Video Motion Detection: A system that uses the video signal from a camera to determine if there is any movement in the picture and set off an alarm.

Video Type Lens: An automatic-iris lens without an internal circuit to control the iris. All iris control voltages come from a circuit located within the camera.

Vidicon: A common type of camera pickup tube. It translates the effect of light striking its photo-sensitive surface into electrical impulses.

Voltage: Electromotive force (EMF), the internationally-accepted unit of measurement for the potential difference between a region with a surplus of free-flowing electrons (negatively charged) and a region with a deficit of free-flowing electrons (positively charged). Voltage induces current flow in a circuit.

VOM (Volt-Ohm Meter): Analog electronic measuring device that measures voltage and impedance.