WRRR

1330 AM WRRR was on the air in Rockford, Illinois from 1953 until 1982.
 

GU2 Radio

Campus radio at the University of Surrey in Guildford, England began with University Radio Surrey in 1972.  They rebranded as Guildford Campus Radio in 1990 and again to GU2 Radio in 2001 (GU2 is the postal code prefix of the surrounding area.)  Today the one watt station is known as Stag Radio, named after the school's mascot Steve the Stag.
 

KYST

KYST "Patriot Talk 920 AM" is a locally-owned, Conservative Talk station in Houston, Texas.  They flipped from a Spanish-language format in 2024 to become that city's fifth Talk outlet along with KTRH, KPRC, KSEV and KNTH.
 

KROI

KROI "Radio Now 92.1" was a Top-40 station in Houston, Texas from 2017 to 2021.
 

KNOR

"La Raza 93.7" KNOR is a Regional Mexican station licensed to Krum, Texas near Dallas.
 

KJLL

AM 1330 KJLL was a Talk station in Tucson, Arizona.  They dropped that format abruptly around 2012 and flipped to a music format with new call letters KWFM.  1330 AM went off the air pemanently in 2021.
 

Radio Malmo

A terribly generic postcard from Radio Malmo in Malmö, Sweden.  The URL no longer works but I think this station is now 89.2 FM Malmökanalen.
 

Concert FM

Concert FM (now known as RNZ Concert) is an FM radio network broadcasting Classical, Jazz, specialist programs and news updates.  They are one of the services of Radio New Zealand, that country's public service broadcaster, and is based in Wellington.
 

KCOH

KCOH is an Urban Contemporary/Talk station in Houston, Texas.  From 1953 until 2013 they broadcast to a primarily African-American audience at 1430 AM but are now located at 1230 AM.

CKSQ

CKSQ is a Country station in Stettler, Alberta.  They switched from 1400 AM to 93.3 FM in 2012
 

WWTJ

"96.9 FM The Way" WWTJ is a low-power Religious station in Watertown, New York.
 

WEZC

A 1986 sticker from Adult Contemporary station "EZ104" WEZC in Charlotte, North Carolina.

Armed Forces Network

The Armed Forces Network is a government radio and television service for military members stationed overseas.  There are 28 manned locations worldwide split between AFN Europe and AFN Pacific.  This link provides access to hours of historical audio and video from the more than 80 year history of the Armed Forces Network.

Planet Radio

88 FM Planet Radio is (or was...I can't tell if they still exist) a community radio station based in Brisbane, Australia dedicated to environmental causes and independent music. 
 

WUTK

90.3 FM WUTK is the student and volunteer-run radio station owned by the University of Tennessee in Knoxville.

 

WPRQ

WPRQ went on the air in the Kingsport/Johnson City/Bristol area of Tennessee in 1984.  This 1986 sticker dates back to their original Contemporary Christian format.  870 AM now has the call letters WPWT and plays Classic Country as "The Possum."  They are a daytime-only station to protect the clear-channel signal of WWL in New Orleans.
 

WMFL

1090 AM WMFL was on the air in (W) Monticello, FLorida from 1969 until some time in the 1990s.  Looking back through various Broadcasting Yearbooks, it looks like they existed like normal until around 1993.  The entries for 1994 through 1997 list them as "not on air, target date unknown" and nothing at all after that.
 

Interlochen Public Radio

Interlochen Public Radio is a network of five National Public Radio stations in Northern Michigan.  Classical music is heard on 88.7 WIAA and 88.5 WIAB while NPR News & Talk are heard on 90.1 WHPB, 91.5 WICA and 89.7 WLMN.  IPR is owned by the Interlochen Center for the Arts in Interlochen, MI.

WEAE

A magnet from 1250 AM WEAE, a Sports station in Pittsburgh, Pennsylvania from 1999 to 2010.
 

WAXC

92.1 FM WAXC was on the air in Wapakoneta, Ohio from 1978 to 1985.  In the early 1980s their transmitter moved north to Cridersville to better cover the larger Lima, OH radio market.  In 1985 they switched calls to WZOQ with a full-blown Top-40/CHR format.