CBC Whitehorse's current AM transmitter, located in the city's Porter Creek area, will be shut down in September. (CBC)

A CBC decision to change its Whitehorse transmitter to FM from AM has people who live in rural areas of the Yukon concerned they'll lose their signal.

Pete Beattie, who lives at Lake Laberge, is one of a group of Yukon residents who have circulated a petition against the move.

Beattie, who says CBC Radio is part of daily life for him and his neighbours, worries he'll lose the CBC signal because AM usually transmits over a larger area than FM.

Beattie also wonders how they'll be kept informed during emergencies like forest fires.

"I suppose it would be easy to think of any number of events like that where the AM signal would be really good," he told CBC News.

Area residents have organized petitions asking both the federal and territorial governments to get involved.

A petition to the House of Commons asks "that Parliament permanently maintain AM transmission from Whitehorse, Yukon (one of Canada's 13 capital cities) so that every rural Yukoner will be able to tune into CBC."

Opposition parties in the Yukon are also urging action to save the AM signal.

CBC North regional director John Agnew said he has no choice but to end AM radio in Whitehorse.

The Radio One transmitter in the city's Porter Creek area has to be removed to make way for residential development, at the city's request, in the new Whistlebend subdivision.

Moving it elsewhere would run into the millions of dollars, Agnew said, so it's far cheaper to add another FM transmitter to the Radio 2 tower on Canyon Mountain, which is known locally as Grey Mountain.

The new transmitter will be more powerful than the current Radio 2 transmitter, he said.

"We are satisfied from an engineering point of view that we will meet the requirements of our broadcasting licence, but how much further the signal will transmit beyond that I don't know," he said.

The CBC has a mandate to broadcast within a 20-kilometre radius of Whitehorse.

In addition to the main FM transmitter on Grey Mountain, a second repeater transmitter will be put on a different hilltop to make sure Whitehorse and the immediate area are served, Agnew said.

The changeover is slated for August, but CBC will broadcast in both AM and FM while technicians work out any glitches in the system.

With files from The Canadian Press, CBC's Dave Croft