Archived—Report on AM Broadcasting Possibilities in The Greater Toronto Area

4. Rules and Agreements

Industry Canada's main regulatory document pertaining to AM broadcasting is Broadcast Procedures and Rules 2 (BPR2), supplemented by general provisions in BPR 1. However, most of the technical criteria to be met by AM applications are found in the 1984 bilateral agreement between Canada and the USA which is referenced in BPR 2.

With propagation being much more complex in the AM band than in the VHF and UHF bands used by FM and TV broadcasting, separation distance tables are impractical and protection from interference is obtained using protected contours and ratios. There are two propagation modes in AM broadcasting, groundwave, where the signal travels along the surface of the earth and attenuation varies with the type of terrain, and skywave, where the signal is reflected off the ionosphere. Groundwave propagation occurs day and night and varies with frequency as well as terrain. Skywave propagation occurs only at night because of the sun's affect on the ionosphere. Thus rules differ from day to night, although the same protection ratios apply. The protected contour day-time is generally 0.5 mV/m and is noise limited. The protected contour night-time is generally interference limited and is calculated for each station.

As mentioned in the Historical Perspective section, there are three classes of station:

  • Class A, 50 kW maximum power, protected to 0.1 mV/m contour day and 0.5 mV/m skywave contour night.

    There are very few class A stations and most use 50 kW with either a non-directional or simple directional antenna. Coverage generally exceeds 100 km day and can exceed 1000 km at night.

  • Class B, 50 kW maximum power, protected to 0.5 mV/m contour day and 2.5 mV/m or existing interference level at night, whichever is greater.

    There are many class B stations with powers ranging from 100 watts to 50 kW, some with very complex directional antennas. Some, mainly in the USA, operate only in the day because they cannot meet protection rules at night. Coverage can range from about 20 km to well over 100 km day, and from a few km to 50 km or more at night.

  • Class C, 1 kW maximum power, protected to 0.5 mV/m contour day and 4 mV/m or existing interference level at night, whichever is greater.

    There are many class C channels, most with 1 kW non-directional power on the former NARBA local channels. Coverage ranges from about 10 to 50 km day, and from about 2 to 15 km at night.

Protection ratios are:

  • co-channel: 20 dB
  • 1st adjacent: 0 dB
  • 2nd adjacent: -20 dB

There is a 0 dB protection ratio for image interference (900 to 920 kHz apart), but exceptions are often made to this rule with little impact. It should be reviewed with modern receivers. There is also a prohibition of overlap of 25 mV/m contours for third adjacent channels.

As noted in the Historical Perspective section of this report, the "expanded band" 1610–1700 kHz is subject to a different agreement, which brings in the concept of "priority channel". The particulars of that concept are described in that section. Other than that difference, the rules above apply. Stations in this band are treated as class C, although they can raise power to 10 kW provided they would not cause more interference than a 1 kW non-directional station at the border.

4.1 Rules Needing Review

Imagineering notes three rules which should be reviewed:

  1. Night-time protection of Class A stations

    Since no protection of skywave service has been required of adjacent channel stations, erosion of that service has resulted. This rule can be looked at from two aspects, both of which could be adopted:

    1. Class A stations should be protected only to their interference-free contour.
    2. Protection from adjacent channel interference should be added.

    Even if the rule is not changed, it can be waived on a case-by-case basis where circumstances warrant.

  2. Image interference

    Exceptions to the image rule rule have been made frequently, accompanied by a commitment to resolve interference complaints. To the best of my knowledge, such complaints are rare, if they occur at all. Receivers should be tested to see if this rule can be deleted.

  3. Third adjacent channel 25 mV/m overlap rule

    Exceptions to this rule have been much less common, but again they have not created serious problems. Again receiver testing can provide an indication whether the rule should remain or be amended. This criterion may be frequency sensitive, a factor to consider in the testing.

I recommend that a B-TAC subcommittee look into these rules. Even if the rules are retained, exceptions should (continue to) be granted when circumstances warrant.

5. Overview of All FM Channels

Channel kHz Stations precluding use of channel
Co-channel Adjacent
  1. *If appropriate combining and filtering equipment can be obtained, using all five expanded band channels at the same site is possible. See Appendix 2.
530 CIAO Brampton  
540 CBEF Windsor 530 CIAO Brampton
550 WGR Buffalo NY  
560 CFOS Owen Sound  
570 CHYM Kitchener  
580   590 CJCL Toronto
590 CJCL Toronto  
600   590 CJCL Toronto
610 CKTB St Catharines  
620   610 CKTB St Catharines
630   640 CFYI Richmond Hill
640 CFYI Richmond Hill  
650   640 CFYI Richmond Hill
660 WFAN New York NY  
670   680 CFTR Toronto
680 CFTR Toronto  
690   680 CFTR Toronto
700   710 CJRN Niagara Falls
710 CJRN Niagara Falls  
720   710 CJRN Niagara Falls
730   740 CHWO Toronto
740 CHWO Toronto  
750   740 CHWO Toronto
760 WJR Detroit MI  
770 WABC New York  
780   790 Brampton
790 can use 790 Brampton  
800 CKLW Windsor 790 Brampton
810   820 CHAM Hamilton
820 CHAM Hamilton  
830   820 CHAM Hamilton
840 WHAS Louisville KY  
850   860 CJBC Toronto
860 CJBC Toronto  
870   860 CJBC Toronto
880 WCBS New York NY  
890   900 CHML Hamilton
900 CHML Hamilton  
910 CKLY Lindsay 900 CHML Hamilton
920 CKNX Wingham  
930 WBEN Buffalo NY  
940 can use  
950 can use Barrie allotment  
960 Cambridge  
970 WNED Buffalo NY  
980 CKRU Peterborough  
990 WDCZ Rochester NY  
1000   1010 CFRB Toronto
1010 CFRB Toronto  
1020   1010 CFRB Toronto
1030 WYSL Avon NY  
1040   1050 CHUM Toronto
1050 CHUM Toronto  
1060   1050 CHUM Toronto
1070 CHOK Sarnia  
1080 WUFO Amherst NY  
1090 CKKW Kitchener  
1100 can use day-time  
1110 can use with limited night operation  
1120 WHTT Buffalo NY  
1130 WBBM Chicago IL  
1140   1150 CKOC Hamilton
1150 CKOC Hamilton  
1160   1150 CKOC Hamilton
1170 WWVA Wheeling WV  
1180   1190 Mississauga
1190 can use 1190 Mississauga day-time  
1200 can use Tillsonburg allotment 1190 Mississauga
1210 WPHT Philadelphia PA  
1220 WKNR Cleveland OH  
1230 WECK Cheektowaga NY  
1240   1250 CJYE Oakville
1250 CJYE Oakville  
1260   1250 CJYE Oakville
1270 WHLY Niagara Falls NY  
1280 LP CFYZ Toronto Airport-see 1280 in Review by Channels  
1290 CJBK London  
1300 WXRL Lancaster NY  
1310   1320 CJMR Oakville
1320 CJMR Oakville  
1330   1320 CJMR Oakville
1340   1350 CKDO Oshawa
1350 CKDO Oshawa  
1360   1350 CKDO Oshawa
1370 WXXI Rochester NY  
1380 CKPC Brantford  
1390 can use Ajax allotment  
1400 WWNS Buffalo NY  
1410 CKSL London  
1420 CKPT Peterborough 1430 CHKT Toronto
1430 CHKT Toronto  
1440 WJJL Niagara Falls NY 1430 CHKT Toronto
1450 CHUC Cobourg  
1460 CJOY Guelph  
1470 can use 1470 Welland allotment; CJOY limits day coverage in west 1470 night combined with 1480 or 1500 day
1480 can use 1480 Newmarket allotment  
1490 WBTA Batavia NY  
1500 can use day-time  
1510 CKOT Tillsonburg  
1520 WWKB Buffalo NY  
1530   1540 CHIN Toronto
1540 CHIN Toronto  
1550   1540 CHIN Toronto
1560 WQEW New York NY  
1570 WBUZ Fredonia NY  
1580 can use day-time, night use questionable; may conflict with 1610  
1590 WASB Brockport NY  
1600 Simcoe  
1610 LP CHEV Toronto, Markham applicationFootnote *  
1620 US channel  
1630 Footnote *see below  
1640 US channel  
1650 can use if 1670 kHz application moves to 1690Footnote *  
1660 US channel  
1670 application (should move to 1650 or 1690)Footnote *  
1680 US channel  
1690 can use if 1670 kHz application moves to 1650Footnote *  
1700 US channel  

The shaded channels are available to serve all or part of the GTA. The type face used indicates roughly the value of the channel as follows:

Type face Bold Italics Normal
Day coverage all GTA all or most of GTA majority of GTA
Night coverage majority of GTA city core part or none
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