News tagged with tv stations
Northern lights take unusual trip down south
A baffling solar storm pulled colorful northern lights unusually far south, surprising space weather experts.
Space & Earth / Space Exploration
Oct 25, 2011 |
4.3 / 5 (3) |
5
Friday is last day to apply for digital TV coupon
(AP) -- The government program that provides $40 coupons for digital TV converter boxes is winding down.
Jul 30, 2009 |
4 / 5 (1) |
0
Another 158 TV stations to kill analog early
(AP) -- Regulators have cleared 158 TV stations around the country to shut down their analog broadcast signals before June 12, when the remaining full-power stations will end theirs.
Mar 18, 2009 |
3 / 5 (1) |
0
New law could free up TV airwaves for mobile use
A new law could result in fewer TV stations on the air, in exchange for faster wireless data services for smartphones and tablet computers.
Feb 28, 2012 |
3 / 5 (1) |
5
Stations must warn if new TV signals lack reach
(AP) -- TV stations must alert viewers if their new digital signals don't reach areas covered by their soon-to-be-defunct analog broadcasts, the Federal Communications Commission has ruled.
Mar 16, 2009 |
2 / 5 (1) |
1
Television channel
A television channel is a physical or virtual channel over which a television station or television network is distributed. For example, in North America, "channel 2" refers to the broadcast or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video (VSB) and 59.75 MHz for analog audio (FM), or 55.31 MHz for digital ATSC (8VSB). Channels may be shared by many different television stations or cable-distributed channels depending on the location and service provider.
Depending on the multinational bandplan for a given region, analog television channels are typically 6, 7, or 8 MHz in bandwidth, and therefore television channel frequencies vary as well. Channel numbering is also different. Digital television channels are the same for legacy reasons, however through multiplexing, each physical radio frequency (RF) channel can carry several digital subchannels. On satellites, each transponder normally carries one channel, however small, independent channels can be used on each transponder, with some loss of bandwidth due to the need for guard bands between unrelated transmissions. ISDB, used in Japan and Brazil, has a similar segmented mode.
Channel separation on over-the-air channels is accomplished by skipping at least one channel between two analog stations' frequency allocations. (It should be noted that there are gaps between certain channels, where numbers are sequential, but frequencies are not contiguous, such as the skip from VHF low to high, and the jump to UHF.) On cable TV, it is possible to use adjacent channels only because they are all at the same power, something which could only be done over the air if the two stations were transmitted at the same power and height from the same location. For digital TV, selectivity is inherently better, therefore channels adjacent (either to analog or digital stations) can be used even in the same area.
For more information about Television channel, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
