8VSB modulation technique - (8-level vestigial sideband) - DTV stations in the U.S. use 8VSB modulation. This is an AM mode wherein the carrier is multiplied by an 8-level digital signal, and then a filter is used to remove all but the carrier and 6 MHz of the upper sideband. ("8VSB" is often used as a synonym for OTA.)
VGA - This acronym is short for the "Video Graphics Array" display mode. VGA resolution is 640 x 480 pixels.
Baseband Video - Unmodulated analog video signal.
Resolution - A measure of the density of lines and dots per line which make up a visual image. Usually, the higher the numbers, the sharper and more detailed the picture will be. In terms of DTV, maximum resolution refers to the number of horizontal scanning lines multiplied by the total number of pixels per line.
IEEE 1394 - Also called Firewire or iLink. Originally a serial bus for PCs, 1394 may or may not become the interconnection standard for DTV products. It is competing with DVI. IEEE 1394 is a spec for a hardware interconnect plus a software shell. But additional software, such as HAVi, is required for connected units to actually talk to each other. Some day 1394 may dramatically simplify the way DTV products interconnect.
OTA - (over the air) - There are about 1500 OTA (terrestrial) TV stations in the U.S.
Bandwidth - The range of frequencies used to transmit the television signal, including picture and sound. Analog television signals have been allocated at 6 Megahertz for each over-the-air channel. Digital channels are allocated the same 6 Megahertz by Industry Canada. However, by the use of digital compression, a combination of up to 5 SDTV programs and/or one HDTV program can be carried in this 6 MHz digital channel.
8-VSB - Acronym for the transmission method used for over-the-air DTV broadcasting in Canada and the USA. Eight discreet amplitude level, "vestigial side-band" broadcast transmission technology. VSB is an analog modulation technique used to reduce the amount of spectrum needed to transmit information through cable TV, or terrestrial broadcasting.
Widescreen - see 16 - 9
Comb filter - A circuit in NTSC sets that separates the color information from the brightness information.
Dolby Pro Logic Surround. This is a 4-channel analog system. During recording, the 4 channels are "folded" into 2 stereo channels. If played back without a Pro Logic decoder, it sounds like normal stereo. This format is becoming obsolete.
IEEE 1394 - Also called Firewire or iLink. Originally a serial bus for PCs, 1394 may or may not become the interconnection standard for DTV products. It is competing with DVI. IEEE 1394 is a spec for a hardware interconnect plus a software shell. But additional software, such as HAVi, is required for connected units to actually talk to each other. Some day 1394 may dramatically simplify the way DTV products interconnect.
PAL - (Phase Altering Line standard) - This alternative to NTSC has 625 lines, interlaced, 50 fields per second. It is used in most of Europe, Asia (except USSR), Africa, and Australia, and parts of South America.
Virtual channel number - This is the channel the consumer thinks he is watching. The actual (physical) channel is selected by a hidden mechanism.
