The concession for XEQK was obtained in 1938 by Ángel H. Ferreira, and the station signed on the next year on 1500 kHz, operating 13 hours a day.
In an era without digital clocks and only limited telephone services, the format was a success for the station and made significantly more money.
Live announcers between the time signals included Jacobo Zabludovsky and Luis Ríos Castañeda, the "distinctive voice" of the station for years.
[2] "La QK", as it was popularly known, found a following in places such as hospitals, cars and businesses where exact time was paramount.
The 1963 full automation system involved modules of 12-minute discs controlled by time signals from the observatory, which were sent several seconds before the minute.
On April 1, 2024, XEQK and XEDTL exchanged their formats, returning Radio Ciudadana to 1350 AM and Tropicalísima to 660 AM.