Final time signal: Canada to switch off CHU

The long-established Canadian time signal station CHU is to permanently cease its shortwave transmissions on 22 June 2026, after almost a century.

The National Research Council (NRC) is withdrawing from the traditional HF infrastructure.

The dismantling of the transmitting installation south-west of Ottawa is taking place for technological and economic reasons. The NRC points to modern, more cost-effective distribution methods such as the Network Time Protocol (NTP) via the internet and web clocks.

For the agency, the financial and energy costs of maintaining the shortwave transmitters are no longer proportionate to the civil benefits.

The end of an era

For HF technicians and radio amateurs, this marks the end of an era of signal monitoring. CHU began with its first experimental emissions in 1923 under the call sign 9CC, before the distinctive call sign CHU was introduced in 1938.

A reliable reference

Since 2009, the station has been using the frequencies 3330 kHz, 7850 kHz and 14670 kHz. For decades, the carrier signals – accurate to atomic clock standards – served as a reliable reference for the amateur radio community, enabling the analysis of ionospheric disturbances, phase shifts and transatlantic propagation conditions in real time.

Until the final shutdown date in June, the operators will continue to accept reception reports for final confirmation via QSL cards.