Call signsCall signs are codes that identify a station. The United States is allocated the prefixes AA-AL, K, N and W. For broadcasting, only K and W are used, derived from the Morse code symbols for A and N, with an extra dash. Except for the oldest stations and translators, all broadcast stations are four letters long. Older stations may have three letter callsigns left over from earlier days, such as San Francisco's KGO or Chicago's WGN. K is used for stations west of the Mississippi River, and W is used for stations east of the Mississippi. Prior to 1923, the dividing line was further west note . Because of this rule change, and other more complicated reasons, there are stations that do not follow the K/W convention. KDKA-AM in Pittsburgh, the oldest commercial station in the United States note , and WOAI-AM in San Antonio, the station farthest west in the continental US with a W, are two notable examples. In Minnesota and Louisiana, where the Mississippi River begins and ends, station can have either W or K. There are also exceptions based upon prior ownership. In the Dallas-Fort Worth area, every television station's call sign starts with a K except for WFAA, because the station was originally owned by the same company that owned WFAA-AM, so it was allowed to keep its W call sign. This practice of allowing call sign carry over continues even today. Stations with a common owner can have the same callsign, but with a different suffix. So there can be a KOPB-AM, a KOPB-FM and a KOPB-DT (for digital television). Other suffixes are "TV" for analog television and "LP" for low power (there's also "CA", "CD", and "LD"). To reach communities outside of the main transmitter's area, translators are used. They have names like K11BX (the number in the middle is the "channel" or frequency assignment where the station operates), and are lower power. The number will also tell you the type of translator: if the number is two digits, it's a repeater of a television station; a three digit number is a repeater of an FM station. Often, religious broadcasters abuse the translator rules and have FM translators scattered across the country. Stations are commonly identified by their callsigns, which can be a big part of the station's branding.
BandsThere are five main broadcast bands in the United States:
- Amplitude modulation, or AM, radio covers 520 to 1710 kHz. This band is mostly used for news, talk and sports radio (a shift from once-commonplace music formats which began in the late '80s). Its advantages are long range and simple receivers. It has low bandwidth, so most music stations have moved to the FM band. Also known as medium wave.
- Frequency modulation, or FM, radio covers 87.9 to 107.9 MHz (87.7 FM, where the audio for analog channel 6 is heard, is also on many radios, with some low-power stations taking advantage of that to air a radio format). The last digit after the decimal point is always an odd number. It is used for all kinds of broadcasts, from college radio to top 40 music. HD radio is starting here as a subcarrier, although the receivers are really expensive now. FM is good for stereo music and can support data streams on subcarriers. Part of the VHF band. News, talk and sports radio are making their ways to FM, slowly but surely.
- VHF TV covers channels 2 to 13. There is no Channel 1.note Starting in February 2009 analog television stations switched to digital stations, and all stations switched by June.
- UHF TV covers channels 14 to 52. Channels above 52 have been allocated to other services, and channel 37 is reserved for radio astronomy.
- Shortwave radio is mostly unused for broadcasting in the United States. What stations do exist are religious (often run by a new "prophet") or operated by fringe groups. You can find official time signal broadcasts there too, among other signals; really cool alarm and digital clocks note can set themselves to these signals.
Standards and RegulationThe Media Watchdog in the United States is the Federal Communications Commission. Besides being notorious for "broadcast standards and practices", the FCC sets the rules for channels, power, and other technical stuff, as well as licensing stations. The United States used NTSC for analog television broadcasting and now ATSC for digital television. HD Radio is the digital radio standard, despite the rest of the world using the DAB standard
NetworksThere is no national government-operated broadcaster. All stations are funded by advertising, donations or money from
In fiction: Radio
- WKRP in Cincinnati is set in a radio station.
- Frasier worked in a Seattle radio station called KACL, AM 780.
- KBBL is a radio station in The Simpsons. There is also KBBL-TV.
- In the 1978 movie FM, the station is referred to as "Q-Sky". This was in the early days of radio stations taking on call letters with Z, X or Q and branding themselves with names like "X93" or "The River."
- The short story "On a Clear Day You Can See All the Way to Conspiracy" by Desmond Warzel takes place at WCUY, a fictitious AM radio station in Cleveland.
- NewsRadio took place in radio station WNYX.
- Storyteller/Songwriter Harry Chapin tells how he is the morning DJ of the radio station in the song WOLD.
- Paul Newman and Joanne Woodward star in a movie about a conservative New Orleans radio station WUSA.
- Billy Batson in the original Captain Marvel works for WHIZ. He hosts a couple of panel shows and reads news and continuity.
- On Hee Haw there was an occasional skit about KORN radio.
- The old American Movie Classics channel used to have a series called Remember WENN, about a station in the 1930s.
- WQHG is the television station in Family Guy.
- Mary Tyler Moore worked at WJM in Minneapolis.
- The "Weird Al" Yankovic cult classic UHF took had two stations whose call letters are never identified, Channel 62 and Channel 8 (the latter of which went dark by the movie's end; the logo for that station looks identical to the logo used by real-life Dallas station WFAA from 1996 to the present day, and during one scene, when one character preps for broadcast, the truck seen in the background is the satellite truck from KTUL-8, the real-life channel 8 in Tulsa, OK, where the movie was filmed)
- In Network, the fictitious fourth network (alongside CBS, ABC and NBC) is UBS (Union Broadcasting Service).
- Murphy Brown worked for the fictitious FYI newsmagazine on CBS in Washington, D.C.