Some stations never change call signs even with these vastly different formats. And some change call signs with every format change. See below with these two examples from the Hartford, Connecticut Market. Then I share 2 stories of 2 other stations with longtime call letters that changed them. One that is a success. The other one that is not.
In Hartford, Connecticut WZMX 93.7 flipped formats seemingly every couple years since they were built from the old WLVH Super 94 in 1991, until they became a success with Hip-Hop in 2001, but they always kept the same call letters.
1991-1994 Hot AC - MIX 93.7
1994-1998 Classic Hits/Classic Rock - 93.7 The 70s Station.
1998-2000 - They made a lame attempt to take on all stations in Hartford playing Rock & Roll. (Playing everything from Oldies - taking on DRC-FM, Classic Rock - taking on WHCN, Modern and Active Rock - talking on both Radio 104 and WCCC). Their name was 93-7 The Point (nicknamed The Pointless)
2000-2001 - Jammin' Oldies. "Dancin' Oldies Z-93.7"
2001-Present - Hip-Hop "HOT 93.7"
Meanwhile every 104.1 FM (licensed to Waterbury, Connecticut) has gotten new calls with nearly every format change.
Mid 1970s WWCO-FM Simulcast of WWCO (AM).
1977ish-1979 Country WIOF
1979-1991 Soft Rock Magic 104 WIOF
July1991-October 1994 Hot AC Star 104.1 WYSR
October 1994-September 2003 Modern Rock Radio 104 WMRQ (I believe they remained WYSR until January 95)
September 2003-October 2007 Hip-Hop Power 104.1 WPHH
October 2007-May 2009 - Automated Rock Music (owned by the Aloha Trust) "FM 104.1" WURH.
May 2009-Present Modern Rock Radio 104.1 WMRQ (Radio 104 and the WMRQ calls returned to 104.1 FM after being sold to the independently owned Red Wolf Broadcasting in 2009).
In the city of Middletown, Connecticut little 1150AM was WCNX from their sign-on in 1946 until 1996 when they became WMRD. WCNX was pretty much a throw-away station from the 80s until the Mid-90s. Several attempts to sell the station during that time period fell through, until Don DeCesare (formerly of CBS Radio in NYC) bought the station. Soon he also bought WLIS in Old Saybrook and have teamed the 2 stations up with an eccentric format. The local morning host plays music. They have local talk host Phil Mikin (10AM-11AM), national Talkers including Stephanie Miller, Dennis Miller, The Duke & Doctor, Lou Dobbs, John Batchelor, and Red Eye Radio), a local Newscast with inserts from Channel 8 at Noon, local shows at 12:30PM (and repeated at 6:30). The weekends feature a wide-variety of specialty shows including: The House of Blues with Dan Akroyd, Celtic Programming, Italian Programming, Jewish Programming, Polka Programing, Caribbean Programming, Breakfast with The Beatles and Rock & Roll's Greatest Hits with Dick Bartley. See their schedule:
http://wliswmrd.net/progamming.htm It's really too bad they don't stream. They are a really interesting station.
In Southington, Connecticut AM 990 was WNTY from the time they signed on in 1969 until 2003. The General Manager at the time said the WNTY call sign was damaged goods as the station had been through numerous format changes over the years. (AC, Spanish Tropical, Hip-Hop, Talk) He changed the calls to WXCT. "XaCT. Radio 990 The X. Yes spelled without the "E"). "News, Weather, Sports, Traffic Xactly when you want it on Xact Radio 990 The X". Ironically now the WXCT call sign is damaged goods. In May 2004 new owners (under an LMA with Anda Productions) flipped the station to Spanish AC. SuperMax 990 (yeah they actually named the station after a prison) In July 2005 they terminated Anda Productions LMA and flipped the station to Spanish Tropical "POWER 990". (Programmed in house rather than through an LMA). - They had the nerve to use the branding "POWER 990" despite the fact Clear Channel was using the name POWER at 104.1 FM. In October 2005 they went rehired the former 990 The X GM and they went talk. "X Radio 990. Talk Radio for Women". In 2006 The GM signed a 2 year TBA (similar to an LMA). The station changed to TalkRadio 990. Unable to make enough money and find a partner, the owner of the station terminated the TBA and in May 2007 the station went Spanish Christian under a new LMA with Radio Cantico Nuevo. If someone buys this station again, I believe they should bring back the WNTY calls. Enough time has passed that those call letters are no longer damaged goods. I don't know if the station can be rebuilt or not, however.