Weatheradio Canada

In the early-1990s, increased government investment permitted major expansion of the network to the present size of 230 sites.

In most locations, the service broadcasts on one of seven specially-allocated VHF radio frequencies, audible only on dedicated "weather band" receivers or any VHF radio capable of receiving 10 kHz bandwidth FM signals centred on these assigned channels, which are located within the larger "public service band".

Since 2004, the service has used Specific Area Message Encoding (SAME) alerting technology to disseminate severe weather bulletins.

Weatheradio has indicated that, in 2021, it also plans to add other hazard and civil emergency information (such as natural disasters, technological accidents, AMBER alerts and terrorist attacks) to its broadcasts.

As of August 2007, most of these AM and FM transmitters were unlicensed by the CRTC under a special license exemption granted to low-power non-commercial broadcasters.

ECCC stated that the transmitters were predominantly located in areas of overlapping coverage and where alternate methods of access (such as cell phones and the Internet) were available.

Broadcast range for a Weatheradio transmitter is approximately 60 kilometres, but this depends on things like terrain, the quality of the receiver, and the antenna height above ground.

[4] The service uses multiple frequencies:[8] At selected locations, low power broadcasts without the alert tone are transmitted on the regular FM or AM band.

This encoding/decoding technology has the advantage of avoiding "false alarms" triggered by the 1,050 Hz tone itself in locations outside the intended warning area.

During potential or actual dangerous weather situations, specially built receivers are automatically activated by this signal to warn of the impending hazard.

The variability, normally more noticeable at greater distances from the transmitter, will occur even though you are using a good quality receiver in perfect working order.