Tag Archives: Mount Royal Antenna

CKOI is moving its transmitter

The CBC's Mount Royal antenna tower hosts most major FM and TV transmitters in the city.

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

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

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.

Antenna work on Mount Royal tower means more overnight transmitter shutdowns

Mount Royal tower.

Mount Royal tower. (Fagstein file photo)

I’ve been getting a lot of questions (and a few conspiracy theories) from irate over-the-air TV watchers over the past few weeks because Montreal-based stations have been going off the air overnight.

Overnight shutdowns aren’t new. The same thing happened last year when they installed a microwave receiver on the tower.

So I asked Martin Marcotte, director of transmission for CBC, which owns the tower, what was up. He explained that this time they’re installing a standby antenna for UHF digital TV stations — CBC, Radio-Canada, Global and V — which allows those stations to be switched to that antenna in case the main one fails. (Ironically, that requires shutting down the transmitters for safety reasons.)

“Our current UHF antenna for DTV is now over 30 years old. Because of new code restrictions on work in confined spaces, we are no longer able to service that antenna. So the standby antenna is required to ensure continuity of service if ever there are problems on our main antenna as we can no longer repair the main antenna,” Marcotte explains.

The shutdowns, which start shortly after midnight, don’t just affect the four stations broadcasting on the UHF DTV antenna, but also the two using the VHF antenna (CTV and TVA) as well as most of Montreal’s FM radio stations, though most of those have standby facilities that allow them to stay on the air at reduced power (you may have noticed some of them being a bit noisy at night — Virgin Radio in particular seems to have a very poor standby signal).

The plan is to keep the UHF DTV antenna until 2022 when it’s scheduled to be replaced. If something breaks before then, that replacement would be moved up.

Installation work for the standby antenna is continuing. It’s expected to be done by Sept. 18, but that assumes ideal weather and no unforeseen problems.

Delivery of TV and radio signals through cable, satellite and online are not affected by this work.

The work has annoyed OTA viewers partly because the CBC doesn’t have a webpage that explains what they’re doing, and partly because there are often things to watch just after midnight. People missed Jon Stewart’s final Daily Show on CTV and part of Stephen Colbert’s first Late Show on Global because of these shutdowns.

You might wonder if delaying the start of work until, say, 1am each night might solve that problem. But then it would either have to continue later into the morning or be extended over more days.

So I guess you’re just going to have to live with it for another week.