Noise

“Noise” is low-level interference in an electronic component resulting from a power supply hum, internal electrical components, or other sources. Noise may also be in the form of radio waves or other signal distortions. Noise is found in all electrical components.

Solid-state electronics tend to have less noise problems than vacuum tube-based components.

The lower the noise rating of a component the better. When looking for an audio/video component, pay attention to the signal-to-noise (S/N) ratio to determine the amount of noise in the component. The S/N ratio is measured in decibels (dB). The larger the S/N number the better.

Non-Interlaced (Progressive)

Also known as progressive scan, non-interlaced refers to the way a video image is displayed on-screen. Each line of a non-interlaced frame (one complete image) is drawn one line after the other, i.e., progressively. This differs from interlaced images that draw the image in two fields where the odd lines are drawn first and then the even lines are drawn to create the final frame or complete image.

Interlaced video is used for the analog NTSC broadcast television standard in the United States. Both interlaced and progressive scan video are used for digital ATSC broadcast television in the United States.

Some DVD players offer progressive scan, but you must have a TV with a component video (RGB or Y, Pb, Pr) connection to take advantage of this capability.

Notch Filter

A notch filter separates chrominance (color) information from the luminance (brightness) information in a composite video signal. A notch filter or comb filter must be used to separate the color and brightness portions of a composite video signal.

A comb filter is better than a notch filter because it provides better resolution and less distortion. Most higher quality video devices use comb filters.

NTSC (National Television Systems Committee)

NTSC is the U.S. government agency that established the analog color television standard in use since 1953. The NTSC standard currently is being replaced by the new digital television standard (ATSC) advocated by the FCC.

NTSC video is transmitted in an analog format using a nearly square 4:3 aspect ratio, providing 525 horizontal lines of maximum resolution. It is an interlaced format that creates two separate fields, one every sixtieth of a second, and combines them to form one complete video frame thirty times per second.

The other video formats commonly used throughout the world are PAL and SECAM.