1 of 1- RadioActive
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If A Stn. Goes Silent, What Does It Mean For Others On That Frequency?
I ask this out of genuine curiosity, not because I think it will ever happen but because of the expense involved for very little return.
As we all know, most AM stations have to adjust their signals at sundown, so as not to interfere with others using the same frequency. In the case of CFRB, for example, you hear a brief interruption at night as the signal contour changes so as not to interfere with WINS in New York, also on 1010.
But what happens when, like in the Rogers case, those stations go off the air for good? Could someone at that dial position elsewhere conceivably file a request with the CRTC (or the FCC in the U.S.) to reach places their previous signal couldn’t?
I’m thinking of the old CJRN. It used to be on 710 AM, before it disappeared for good in November 2012. Despite the fact it’s gone, I still can’t hear WOR in New York on the same frequency, which is nulled towards this part of North America. Could they change their contours to now reach here at night, knowing there’s no one left to interfere with? Or is the pattern they’re assigned sealed permanently forever and can't be altered?
Has anyone ever actually applied to do this?
I’d be curious to know how this works, now that 570 is open in this part of the country.
- tvguy
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Re: If A Stn. Goes Silent, What Does It Mean For Others On That Frequency?
Perhaps Skywave can comment as he's had a lot of experience with AM. Through a North American treaty, Canada the US and Mexico are obligated to provide protection to frequencies in adjacent countries. It is my understanding that if WOR wanted to change their night time pattern (that's where skywave reflection extends the signal at night), the treaty would need to be modified, for the 710 frequency. I don't see Canada wanting to grant concessions these days even when we know full well that those stations "aren't coming back". It does provide an opportunity for re-licensing less directional or non-directional facilities in Canada on the abandoned frequencies, for example 900 - chml's old frequency has been re-licensed to CHIN to operate around York Mills and Lawrence. But the power is much reduced at night versus CHML, because of the nature of the CHIN antenna (non directional).
Last edited by tvguy (July 10, 2026 11:05 am)
- Scarboroughbluffsradiof99
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Re: If A Stn. Goes Silent, What Does It Mean For Others On That Frequency?
Maybe chin should change there aplication somehow and apply for 570, but would that actualy make there signal better with sportsnet 590 neer by?
- Skywave
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Re: If A Stn. Goes Silent, What Does It Mean For Others On That Frequency?
The 1984 Canada/US AM Agreement states:
"Article X
Periodic Review
Recognizing that the Agreement is intended to remain in effect for an indefinite period, the Parties agree that, no later than five years after the date of the entry into force of the Agreement pursuant to Article XII, and no later than the expiration of each successive five-year period thereafter, each Party shall designate and notify to the other those of its assignments in the Plan not yet brought into use that it wishes to retain in the Plan. Assignments which have remained unused for at least five years, and which are not so designated and notified shall lapse and be automatically deleted from the Plan at the end of each such five-year period."
So strictly speaking, the 710 assignment for Niagara Falls would have been automatically deleted, but the actual practice is that, unless an administration deletes an assignment AND notifies the deletion to the other administration, it remains in the list.
Domestically, ISED has adopted a flexible approach which allows a Canadian assignment to be deleted or downgraded on a case-by-case basis. The Canadian frequencies which have gone silent can either be re-used in the same city, or alternatively in another location. The shutdown of 960 in Cambridge and 950 in Barrie allowed for the introduction of CKNT in Mississauga. The shutdown of 980 in Peterborough and Quebec City allowed for CHRF 980 in Montreal (in turn now defunct). And as already noted by tvguy, the shutdown of CHML 900 opened the door for CHIN 900 in Toronto.
- Radiowiz
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Re: If A Stn. Goes Silent, What Does It Mean For Others On That Frequency?
Just because a radio station CAN reach a certain area more freely now, does not mean it's a good idea to take advantage of that.
The idea is to be an advertising business, but if reaching an audience that the product is not intended for, what's the point? Nobody is going to go all the way out to that American town just to shop, and vice versa.