Technical Glossary
This glossary contains definitions of words in our site that you may not understand. Choose one of the searches below to find the appropriate definition.

Keyword Search
Search by word and click GO.

Alphabet Search: Search by any letter of the alphabet.
Displaying 27 glossary terms found.


National Association of Broadcasters. The body which sets standards for U.S. broadcast stations.

National Association of Broadcasters
NAB. The body which sets standards for U.S. broadcast stations.

National Television Standards Committee
NTSC. The U.S. video standards committee.

Near Field
The area in a room which is in the immediate vicinity of the sound source.

Needle Pulse Pattern
A test pattern used to qualify the maximum setting of the peak white level with the Contrast Control. The Needle Pulse test pattern checks the condition of the high voltage power supply, which provides the energy needed to obtain light from the picture tube.

Two or more devices (or people) that can communicate with each other and share resources.

Nickel cadmium recharagable battery.

Near Instantaneous Companded Audio Multiplex. A method of transmitting stereo TV sound. Used in the UK, Scandinavia, Italy, Hong Kong and Singapore. Left and right channels are converted to a digital signal and transmitted at a rate of 728 kilobits per second upon a subcarrier spaced 6.552 MHz from the picture carrier.

A point or line where minimal motion takes place.

1) Unwanted sound generated by signals that have corrupted the original or desired signal. Interference of an electrical or acoustical nature. Analog film sound formats (optical and magnetic) are known to have substantial noise levels in the high frequency range (hiss). 2) Random noise is a desirable signal used in acoustical measurements. Pink noise is random noise whose spectrum falls at 3 dB per octave: it is useful for use with sound analyzers with constant percentage bandwidths. 3) Undesirable interference of picture.

Canceling - A microphone designed to cancel ambient noise so that it will not be broadcast or recorded. The housing of the microphone allows noise to reach both sides of the diaphragm simultaneously, one side canceling the other out. A close speaking voice strikes the diaphragm on only one side, generating a stronger signal with less background noise.

Noise Criteria
NC. Standard spectrum curves by which a given measured noise may be described by a single NC number.

Noise Floor
Normally the lowest threshold of useful signal level.

Noise Limiter
A circuit that reduces audible noise in a signal.

Non-Broadcast Television
Technically, the signal must be broadcast to become "television."

Non-Composite Video Signal
A video signal that contains picture and blanking information only, with no sync information.

Also called progressive scan. a method by which all the video scan lines are presented on the screen in one sweep instead of two. See Interlaced and Progressive Scan.

A system of video recording that uses one head to scan one field of video on the tape.

A deep, narrow frequency response dip.

Notch Filter
A filter of extremely narrow bandwidth used to eliminate discrete frequencies. Notch filters are usually tunable, and can be used to eliminate specific room or instrument resonances.

Notch Filter As Applied To A Comb Filter
Once the Comb Filter removes the color information from the black and white or luminance information, residual color may still be present in the black and white image in less expensive versions of this type of decoder. Expensive, high quality Comb Filters usually don't have this problem. A narrow notch filter is used to get rid of any remaining carrier in the luminance position of the signal. It is often switchable, meaning that you can turn it off. The choice of positions for best quality picture will be set dependent.

Notch Filter Decoder
A NTSC to RGB decoder that significantly limits horizontal resolution.

Notch Filter Decoder
This filter was the first type to be used in decoding NTSC to RGB. It treats all picture information in the area of the color carrier frequency as color information. The notch filter takes out everything in the frequency space of color information, including any luminance information interleaved with the color. All of the information removed by the notch filter gets sent off to the color processing circuits. Luminance resolution on a set containing a notch filter decoder will be poor, often limited to about 240 horizontal lines per picture height. It is still common on most inexpensive sets. A Notch Filter can also be applied to an inexpensive Comb Filter.

National Television Standards Committee. The color television standard for North America (adopted by the FCC for use in the United States) and parts of South America and Asia having 525 lines/60 Hz (60 Hz refresh). Two fields per frame and 30 frames per second. NTSC is also jokingly referred to as "Never Twice The Same Color." The NTSC system for color television was established in late 1953. As it was set out on paper, it was a theoretical, all electronic system based on a solid science assembled by the Commission International de l'Eclairage, CIE, the International Commission on Illumination, in 1931.

NTSC To RGB Decoder
Our color television system starts out with three channels of information, red, green, and blue. These three separate pieces of information are then encoded onto a single channel of video information called a composite NTSC video signal. In order to display the information contained in the NTSC composite signal it must be decoded, deriving the red, green, and blue signals needed to drive the color display. Every TV set that is capable of accepting a composite or S-Video signal must have a decoder built in. Adjusting the Color and Tint controls calibrates the decoding process. See Decoder.

Number Of Pixels
This applies to display devices with individually addressable elements for picture resolution. The LCD, Digital Micromirror Device and Plasma display all fall into this category. The higher the pixel count, the better the resolution capability of the display device. A minimum of 640 by 480 is required to properly display any NTSC sourced signal. The number increases to 800 by 600 for the PAL system and at least 1280 by 720 for any high resolution 1.78:1 aspect ratio picture. The best possible quality for a given array will be obtained when the input matches the display device. Playing an NTSC source on an 800 by 600 display would require a scaling of the video or using only 640 by 480 of the elements. Scaling often doesn't stand up to projection.

Number Of Speakers
Indicates the number of speakers found on a particular television set. Obviously, for people that do not plan to hook-up or attach additional external speakers, more is better.