The CBC’s Mount Royal antenna tower hosts most major FM and TV transmitters in the city.
All major commercial FM radio stations in Montreal except one broadcast from antennas on a single giant transmission tower at the top of Mount Royal.
Soon, the sole holdout will be joining them.
CKOI’s current antenna atop the CIBC building
Last week, the CRTC approved (without any public process) an application to move CKOI-FM 96.9 from its current location atop the CIBC tower at Peel St. and René-Lévesque Blvd. to the Mount Royal tower.
Cogeco’s application explains that, with the move of television stations to digital, and the channel change of Radio-Canada and CBC TV transmitters from 2 to 19 and 6 to 21, respectively, the old VHF TV antenna used by them has become obsolete and is being removed. That will open up a space for a new antenna, and Cogeco wants to install it.
There are a few benefits to this. One, Cogeco’s other FM stations (CFGL-FM 105.7 and CHMP-FM 98.5) already broadcast from the Mount Royal tower, and moving CKOI would allow all three to be managed from one site, the company says. Also, because the antenna would be higher (277.6m instead of 220.8m above average terrain), its transmitter can reduce power but still cover the same area.
Finally, Cogeco says the new antenna will be compatible with HD Radio. It’s unclear if Cogeco has immediate plans for HD Radio or if it’s more of a long-term option, but other broadcasters are starting to use it now and CKOI would be ideal both because of its high coverage and because there are no stations close to it in frequency.
What makes CKOI unique in Montreal isn’t just its location, but also its power. According to the Canadian Communications Foundation, the station was authorized to use 307 kilowatts of power in 1962, when commercial FM broadcasting was just beginning in the country (at the time, the station was CKVL-FM, and was transitioning from being a mere repeater of CKVL to having its own programming). Because of grandfathered rights, it got to keep that power level even though FM stations are now limited to a maximum of 100kW. CKOI is one of only five stations in Canada allowed to go beyond 100kW, and it’s the second-most powerful transmitter in the country after Winnipeg’s CJKR-FM (310kW).
The grandfathered rights, however, don’t mean CKOI can move to the Mount Royal tower and blast out 307kW. When asked to approve the change, Industry Canada (or whatever it’s called now) said CKOI could continue exceeding the 100kW maximum provided its coverage area did not increase, that there was no increase in interference to existing stations or aircraft navigation, that the new installation respects safety regulations relating to transmission power, and that there is no objection from the U.S. Federal Communications Commission.
As a result, CKOI has proposed an effective radiated power of 147kW, which is as high as it can go without exceeding its previous coverage to the west. (This will drop it to fourth-highest power in Canada, after London’s CFPL-FM, 300kW, and Winnipeg’s CBW-FM, 160kW.)
Current (blue) and proposed (green) contours of CKOI-FM
The new pattern slightly reduces how far the signal goes toward the east and south, but probably won’t be too noticeable. (Cogeco estimates that 99.6% of the population in the previous coverage area will still be in the new one.) The higher antenna height will also mean the signal will face less disruption from the mountain and tall buildings.
(147kW might sound a lot higher than 100kW, but because of the way propagation works, the coverage area isn’t that much larger. Compare CKOI’s current pattern to CKBE-FM’s 100kW signal for an idea of how different it is.)
As a bonus, people going through central downtown won’t have their FM radios so overloaded by a 307kW transmission just above their heads that they hear CKOI all over the FM band.
