Years after TV stations in Canada's larger cities were required to switch from analog to digital transmission, many broadcast towers that serve smaller areas continue to pump out signals that black-and-white sets made in the 1950s can still pick up.

But the number of those stations appears set to shrink following a federal government decision to clear a large portion of the ultra high frequency (UHF) band for wireless users, and, because of cost, some of those towers will be going dark.

That means viewers without cable TV or Internet won't get those stations anymore.

"We had to make the hard decision to shut it down," said Tom Lister, operations manager for Miracle Channel, about the station's analog transmitter that serves portions of southeastern Alberta, including Medicine Hat.

Miracle Channel, a Christian broadcaster based in Lethbridge, Alta., will still broadcast a digital over-the-air signal from its main transmitter. But the analog transmitter based in Bow Island, Alta., sends its signal on Channel 39 which is in the bandwidth that needs to be cleared.

Innovation, Science and Economic Development Canada has said Miracle can move lower on the dial to Channel 20.

Lister said the conversion would cost roughly $100,000 and with additional maintenance that would be required, the expense is too much to bear.

The power will be switched off some time this summer, Lister said. There are no plans to replace it with a digital signal.

Analog signals in North America use a standard that was developed in the mid-20th century. It's the same standard that beamed programs such as "The Friendly Giant" to Canadians as well as the 1972 Canada-USSR hockey series.

Provincial capitals and broadcasters in cities with populations over 300,000 were required to convert their analog over-the-air signals to new, higher-quality digital signals in 2011, but analog transmitters serving many smaller places were allowed to keep running. Most are repeater transmitters which carry signals from big-city stations.

Some of those broadcasters have already stopped providing over-the-air signals due to cost of operations and limited over-the-air viewership.

Repurposing the 600 megahertz (MHz) bandwidth is being done in conjunction with the United States, a spokesman for Innovation, Science and Economic Development said in an email.

Hans Parmar said more than 70 per cent of broadcasters will not be affected. And stations in the repurposed 600 MHz band that are not interfering with mobile services or other broadcast stations will only be required to move on an as-needed basis.

"These measures will not only enable the delivery of better and faster wireless services to Canadian consumers and businesses, it will also drive down prices," Parmar said.

The affected broadcasters will have a minimum of two years and up to five years to implement the changes, Parmar said. The first changes will not begin until June 2019.

The Canadian Association of Broadcasters has called for financial assistance to help with the costs associated with the change.

Wayne Rabishaw, director of operations for CHCH-TV based in Hamilton, Ont., said the station is still evaluating the cost for converting some of its analog transmitters that serve places such as Sault St. Marie and Sudbury.

He said their London, Ont., transmitter was converted to digital in 2011, but will have to move again because it's in the frequency the government wants for wireless.

"The last thing we want is for people who are counting on us to lose the signal, but it's not a cash-rich environment right now for Canadian broadcasters," said Rabishaw.

CTV Calgary also has to move two of its repeater stations in southern Alberta further down the dial.

"Our intent is to keep them going," said Dale Coutts, the station's operations manager.

News from © The Canadian Press, 2017