From Wikipedia:
HD2IOA is the callsign of a time signal radio station operated by the Navy of Ecuador.[1] The station is located at Guayaquil, Ecuador and transmits in the in the HF band on 3810 and 7600 kHz.[2].
The transmission is in AM mode with only the lower sideband (part of the time H3E and the rest H2B/H2D) and consists of 1 kHz tone pulses repeated every second and voice announcements in Spanish.
While sometimes this station is described as defunct, reception reports of this station on 3810 kHz appear regularly at the Utility DX Forum