What fake radio and TV stations exist in fiction? Obviously, there’re a lot, but I thought it might be fun to compile a bit of a list.
There’s WGBS broadcasting in Superman’s Metropolis.
In Airplane!, there’s WZAZ-FM, “Where disco lives forever” - call sign modelled on the names of the writers : Zucker, Abrahams, Zucker.
WKRP in Cincinnati
KBBL (from the Simpsons)
WXYZ was Billy Batston’s station in the original Captain Marvel
Just before I left Salt Lake City, WKRP started broadcasting from there. No joke (as they had to keep repeating).
And, yes, WKRP, even though it was west of the Mississippi. he rule’s not ironclad.
Back when I was an undergrad, WTBS used to be the MIT student radio station, by the way. Turner musta paid big bucks to buy it. It use to be Tech Broadcasting System. Now they have some undistinguished name with numbers in it.
WNYX in New York, from Newsradio.
WABBIT in various Loony Tunes shorts.
And their chief competitor: WPIG.
And in Wayne’s World 2, we see a different WPIG, in Aurora.
KCUF in Thomas Pynchon’s The Crying of Lot 49, a set of call letters that quite clearly would never meet FCC approval. 
Spell it backwards.
WPLJ in the Frank Zappa song. Later, a station in New York City took the call letters, so it now exists, but it was fictional when Zappa wrote the song.
WINO from George Carlin (“Wonderful Radio Wino!”)
Network 23 from Max Headroom
WENN, on the show “Remember WENN” on AMC.
The 275-watt Radio OKKK in the Tuna two-man plays.
[Arthur Carlson] Those swine! [/AC]
**WOLD **in the Harry Chapin song.
The Wireless Wizarding Network (WWN) in the Harry Potter books.
KBLY (K-Billy) - Reservoir Dogs.
ZBC (Zoblotnick Broadcasting Corporation) – David Lynch’s On The Air.
Rutland Weekend Television , from whence came the film The Ruttles .
Babylon 5’s ISN, which provided a seemingly objective view into the doings of Earth. Until season 3’s “Severed Dreams”, when…
[spoiler]"… and we’ve been unable to determine at this time how many have been killed on the recent attacks on Mars by Earth Gov. Forces. President Clark has announced that the attacks will continue until the Mars Provisional Government accedes to Martial Law. So far there’s been no reaction from any of the outer colonies concerning these attacks…"
‘I’m sorry, Jane. I’m sorry I jumped in like this, but we have to… the colonies at Orion 7 and Proxima 3, have just broken away from the Earth Alliance in protest over the bombing of Mars. They’re setting themselves up as independent states until such time as President Clark is impeached. Clark doesn’t want this information released but we have to go with this now cause we don’t know how much longer we can stay on the air. Armed troops have begun moving in on the ISN Broadcast Center here in Geneva. We just saw them coming around the corner. We’re trying to get a camera down there to document what’s going on. I can hear gunfire now, up here on the fourteenth floor. Listen to me, there’s information you don’t have, that’s been going on for the last year that we haven’t been allowed to tell you…’
Yikes. That, to me, is the most chilling scene in that arc.
From the Grand Theft Auto games :
Chatterbox
Head Radio
Flashback
CSR 103.2
K-Rose
KDST ( The Dust )
Playback
Radio X
WCTR
Radio Los Santos
Emotion 98.3
Fever 105
Flash FM
K-Chat
V-Rock ( the Vulture )
VCPR
Wildstyle
Wave 103
WKOMA from The Simpsons
Season 3 Homer Alone
“This is Coma-WKOMA. Restful, easy listening. Coming up next, a super set of songs about clouds.”
WJM from the Mary Tyler Moore show.
Clearly fictional, since women as hot as Bailey Quarters simply don’t exist in real life.
I don’t remember the call letters of the station, or even if it had call letters, but I loved the dismal little rural radio station in O Brother Where Art Thou, and I especially loved the blind radio station manager.
“Hooooeeey, that’s some mighty find pickin’ and singin!”