Archived—Report on AM Broadcasting Possibilities in The Greater Toronto Area
I wish to acknowledge and thank Jean Alain of the Broadcast Applications Engineering Division for the excellent technical support, especially the provision of the maps included in the report.
Thanks are also due to Paul Vaccani and Kirit Mehta for their excellent constructive comments and ideas, and to both Kirit and Jean for ensuring that I had the necessary software and materials to carry out this project.
I also acknowledge with thanks the contribution of Gordon Elder, whose expert analysis of the possiblity of sharing the existing Toronto Island facilities which he designed and built, are shown in Appendix 1.
3. Historical Perspective
AM broadcasting has existed since the early 1900s, the first commercial station being CFCF Montreal on 600 kHz. The first international agreement was the 1937 North American Regional Broadcasting Agreement (NARBA), revised in 1950 when the top of the band was moved from 1550 to 1600 kHz. This agreement included, though not all at the same time, Canada, USA, Mexico, Bahamas, Dominican Republic and Cuba. It included basic protection criteria which are still mostly applicable today. It also included a division of channels, with some "clear" channels designated for national coverage, a good number of regional channels which generally were capable of serving large metropolitan areas and a few local channels intended for simple inexpensive operations to serve small cities and towns.
In 1982, with the signing of the ITU Region 2 Agreement (Rio 1982 Agreement), the channel designations in NARBA were replaced by class designations. The "clear" channels were replaced by class A which have substantial, but not national, service contours. The local channel stations became class C, mostly 1000 watts non-directional, and everything else became class B. Simultaneously with ratifying the Rio 1982 Agreement, Canada abrogated, i.e. officially withdrew from, NARBA The Region 2 agreement was complemented in 1984 by a bilateral agreement between Canada and the USA which elaborated the technical criteria somewhat and added a number of allotments which made use of the relaxed protection of the former clear channel stations. Many of these allotments were quickly taken up by existing stations to improve their coverage. For example, CFGO Ottawa improved day and night service moving from 1440 to 1200 kHz, and CFGM (now CFYI) Richmond Hill, which had fairly good day service and very limited night service on 1320 kHz, now serves the entire GTA, day and night, on 640 kHz. Figures 1 shows the present coverage of this station, which is typical of the low frequency, high power Toronto stations located south of Lake Ontario. Of these former clear channels, only 1200 kHz and possibly 1500 kHz still offer the possibility of new service both day and night in the GTA.
In 1988 another Region 2 agreement expanded the AM broadcasting band upwards from 1600 to 1700 kHz. This agreement divided the ten new channels equally among neighbouring countries in border areas, e.g. 1610, 1630, 1650, 1670 and 1690 kHz for Canada and 1620, 1640, 1660, 1680 and 1700 kHz for the USA. On its "priority channel", a country can put a 1 kW non-directional station anywhere within the area designated in the Agreement or can increase power up to 10 kW provided that interference would be no worse than could be caused by a 1 kW station at the border. This "expanded band" has hardly been used in Canada with only a few low power stations, mostly on 1610 kHz. It offers good possibilities for ethnic broadcasting in the GTA and includes two current applications.
A practice in the 1990s by AM stations with modest service who were also looking for the higher fidelity available in the FM band was what the CRTC referred to as AM-FM flips. This has also left a few AM channels which can provide a degree of service in the GTA. Most notable is the former CBC channel of 740 kHz, which has superb GTA coverage. This channel has been taken over by a new operator, who is leasing the CBC facilities and using them exactly as before. A bi-product of this is that the new operator, who already operated an ethnic station in the GTA has increased the ethnic programming on that station Three other interesting channels, which are studied in detail, are 950 kHz from Barrie, 1390 kHz from Ajax and 1470 kHz from Welland.
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