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Tag: Time Signal

CHU Time Signal QRT on June 26th

After nearly 103 years of faithful service, Canada’s shortwave time station CHU will cease transmissions on June 22, 2026. Operated by the National Research Council (NRC), the station has been a reliable source of official Canadian time since 1923.CHU broadcasts automated time signals 24 hours a day on the frequencies 3330 kHz, 7850 kHz, and 14670 kHz. The transmissions include spoken time announcements in both English and French, derived from highly accurate atomic clocks.

For many radio amateurs, shortwave listeners, and people in remote areas, CHU has been the primary way to obtain exact time for decades.The closure fits into a broader trend in which shortwave technology is being replaced by modern alternatives such as GPS, internet time servers, and mobile networks. According to the NRC, shortwave broadcasts are no longer necessary for distributing official time.

My own QSL from CHU Ottawa

The announcement has caused disappointment among radio hobbyists worldwide. CHU was regarded as one of the oldest and most stable time stations in the world, comparable to the American WWV. Many of us have the CHU QSL card showing Sir Sandford Fleming, the man who proposed the introduction of standard time zones on the cover.

”Listeners can still receive the station until June 22, particularly at night and in the early morning hours when propagation conditions are favourable. After that, silence will fall on the familiar frequencies. An iconic piece of radio history will be lost.

QSL DCF77 Time-Signal 77.5 kHz

QSL DCF77 Mainflingen
QSL DCF77 Mainflingen Time-Signal 77.5 kHz

I received this beautiful QSL card DCF77 Time-Signal on 77.5 kHz by mail. The transmitter is located in Mainflingen, Germany. The QSL was accompanied by a folder on how time is managed. I also received a 2009 magazine from the PTB (Physikalisch-Technischen Bundesanstalt) with a special topic on 50 years of DCF77. This magazine is also available online. I sent my report to dirk.piester@ptb.de .

As you can read on the QSL there is no voice announcement of the time. Instead the date and time are transmitted by in code through the interval between second markers (0.1 s = “zero”; 0.2 s = “1”). You can see this in my waterfall map below. The gap prior to second 53 and 57 is twice as big. At the minute there is no gap.

DCF77 signal. The binary code is clearly visible.

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