Radio station CHOU 1450 AM, which airs programming in Arabic, French and other languages from the Middle East, has applied to the CRTC for permission to setup a low-power rebroadcasting transmitter on FM to help alleviate reception problems in the city’s northeast.
The transmitter would operate at 104.5 FM with a power of 50 watts, from an antenna on top of the Sami Fruits building on 19e Ave., near Pie-IX and Jarry.
The station’s primary transmitter is 2,000 watts from the St-Laurent industrial park. In its submission to the CRTC, the station says it has looked at other ways to improve its signal, including increasing power with a directional antenna, but that adding another antenna to its main transmitter site isn’t a practical solution.
Realistic pattern of the new CHOU retransmitter
Montreal doesn’t have much empty space on the FM dial, so trying to squeeze in another station, even a low-power one, is bound to cause some problems.
The biggest source of problems here would be CBME-FM-1, the retransmitter of CBC Radio One at 104.7 FM in the west end. Because they’re so close together, there would be interference between the two. Because the CBC transmitter is more powerful, that interference would be closer to where the CHOU retransmitter will be located. CHOU’s broadcasting engineer mapped out the interference pattern like this:
Red splotches mark places where CHOU may cause adjacent-channel interference with CBME-FM-1 at 104.7.
Normally, this kind of interference would kill an application in its tracks, unless the other station agreed to accept the interference. But CHOU argues that, because CBME-FM-1 is a retransmitter designed to cover Westmount, NDG, Côte-des-Neiges and Hampstead, where the main CBC transmitter at 88.5 was apparently experiencing reception problems, people in affected areas will be listening to the station at 88.5 anyway and won’t mind not hearing the retransmitter.
We’ll see if the CBC agrees with that logic.
The CRTC is accepting comments on the proposal until Oct. 31. Comments can be submitted through the CRTC’s website here. Note that all information submitted to the CRTC, including contact information, becomes part of the public record.
What’s up with the old map? It is to my estimate dating at least to 1996.
There’s no rule saying that broadcast engineers have to update their maps regularly. As long as they don’t move the mountain, I don’t think it matters much.
It is certainly an interesting argument that the applicant is putting forward. I would be very curious to know just what the size of the listening audience is to CBC’s 104.7 relay. I tend to feel that it is very small. The CBC’s 104.7 transmitter/antenna puts out quite a potent signal reaching far beyond its intended target area. I’m not sure of the power output of CBC’s transmitter but I really think that CHOU’s proposed 50-watt transmitter on 104.5 would be affected by the 104.7 signal in the target area, particularly given the poor quality of the majority of FM radios being manufactured and sold today.
CBC’s CBME-FM-1 transmitter has an average effective radiated power of 98 watts. But it’s also a lot higher than the proposed CHOU retransmitter – 97.5 metres above average terrain vs. 22.5.
A little off topic but does the number of frequencies assigned to an area remain static forever? The population doubles tomorrow and can support an additional 10 stations — what happens?
It’s not really done that way. There isn’t a set “number of frequencies” that are assigned to specific areas. Rather, each new application for a broadcast radio transmitter has to fit certain criteria, including that they don’t cause interference to other existing stations within their approved service area. Older stations that didn’t have much competition got approval for high-powered transmitters of up to 45,000 watts on FM and 50,000 watts on AM. (CKOI, thanks to a grandfathered licence, has a 307,000-watt transmitter.)
As the FM band had more and more stations, both in Montreal and in surrounding areas, we ran out of frequencies that could support full-power stations without causing interference. In 2007, the CRTC declared that there are practically no more frequencies available on FM.
But if you reduce the power enough, you can fit in more transmitters, such as what CHOU is trying to do here. Another strategy is to set up medium-power transmitters in suburbs, which allowed for a 600-watt station in Kahnawake and a 500-watt station in Hudson.
The FM band has a set width = 88 to 108 MHz, and that’s unlikely to expand soon. So the CRTC can’t really add frequencies to make space for more stations. There’s still some space on AM, but that band is also filling up fast.
My take here is that the CBC is already pretty much a frequency hog in Montreal, and shouldn’t be an obstacle to this at all. They should be actually asked to more carefully contour their extra transmitter to limit it’s signal past the very limited listener base they are trying to address.
Moreover, the only way there will ever be more FM frequencies in Montreal is if there is a fairly big re-do of all channel assignments on FM in the area, and some careful reconsideration of uses and transmission patterns. That will likely never happen, as the incumbents would never want to lose their branded frequency.
The more likely longer term (and I mean much longer term) is the replacement of AM and FM with a digital variation on different frequencies. I know, tried before and failed, but just like digital TV, at some point they will press the button and a 10 year plan will go into effect that will move us towards the next level. It is particularly interesting here because the bandwidth of a single TV channel you could put pretty much all of Montreal radio and have a ton of space left over, and the cost of a single transmitter could be shared by all users involved. It could also give rise to national networks, and could make it possible (within limits set by the CRTC and moved by large companies) to offer out of market programming (ie international stations) without huge cost increases. It could also mean a cellular style handoff where over a given area the same stations could be on a number of transmitters to allow even coverage over a signficant area – say like the Quebec City to Montreal corridor.
Basically, radio could be put in the same band as currently allotted to TV, take 1 or 2 channels, and return the current large bandwidth attribution in both the FM and AM bands.
Anyone up for it?
The difference between radio and TV is that the digital TV transition didn’t affect 90% of the population because they were getting their TV through cable or satellite service. Plus, new televisions were being built with digital receivers for years before the switch happened.
Plus, after the failure of DAB, broadcasters are going to be pretty hesitant to try again with an entirely new system that requires new receivers. If we’re going to switch to digital radio, we’ll need to come up with a protocol, then build receivers and transmitters, and wait for the market to adopt it. And that might take a while.
Actually, the current DTV standard allows for upwards to 120 audio channels (mono), which means that the CURRENT DTV tuners could be adapted as tuners for a digital radio receiver in the same band, and compress the current wide radio band down to a couple of channels in the TV band. As a bonus, it would mean that all the current TV sets would be able to tune into radio as well :)
DAB has failed mostly because it is a crappy format (originally mpeg-1 encoding, which was fairly low fidelity) and also because in the US and Canada it was sort of usurped by the DBS sat radio networks. Only the subscription nature of those services keeps them from being a true universal tool.
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