End of an Era: The Final Seconds of Shortwave Station CHU

On June 22, 2026, a century-old heartbeat on the shortwave bands officially went silent. Broadcast from the National Research Council outside of Ottawa, Ontario, station CHU dropped its carrier for the final time at 14:10 UTC (10:10 AM EDT), marking a somber and historic milestone for shortwave radio listeners (SWLs), mariners, and amateur radio operators worldwide.

 First hitting the airwaves in 1923 under the experimental callsign 9CC, the station ultimately became known as CHU in 1938. For decades, it provided an irreplaceable service for equipment calibration, ionospheric propagation research, and navigation across the three legacy frequencies:

• 3,330 kHz (3 kW)

• 7,850 kHz (5 kW)

• 14,670 kHz (3 kW)

Unlike other automated time stations, CHU was famous for its human element—the distinct voice announcements alternating each minute between English (Harry Mannis) and French (Simon Durivage)—as well as the unique 300-baud digital modem chirp broadcast between seconds 31 and 39.

💔 WHY DID IT SHUT DOWN?

According to the National Research Council (NRC), the closure was driven by a combination of major budget reallocations and the unsustainable cost of replacing aging, 1960s-era transmitter infrastructure. As modern networks pivot entirely toward internet-based protocol synchronization (NTP) and GPS, the physical HF transmitters were deemed too costly to maintain.

However, many in the amateur radio and scientific communities view the shutdown as a short-sighted loss of a vital, ground-based fallback infrastructure that remains completely immune to satellite cyberattacks or space weather anomalies.