cm3020prob said:In the case of Montreal, CBS (22) is next to CBC (21), NBC (14) is next to Global (15), which I get no reception during the day. Fox (43) operates at a lower power than CBS and NBC so it can be difficult sometimes, ABC (13) is next to CTV (12) but it's at very low power, as in, forget it. But I get PBS-57 (38) and PBS-33 (32) without any problem as they have no co-adjacent channel problem.
Assuming that they are both DTV stations, the ATSC standard has dramatically reduced ACI (Adjacent Channel Interference) from the bad old days. The best proof of this I can think of is in Seattle where KOMO on 38 and KIRO on 39 have side-by-side towers pumping out about a megawatt each.cm3020prob said:If the american RF signal is far but strong enough, placing their transmitter on a RF channel next to the american one will make it difficult to receive.
In your case though other interference sources may have an additive effect on the distant U.S. stations. Your own Montreal reception problems with adjacent channels has almost everything to do with your location in relation to those U.S. stations, so we can carry this on in your local reception thread as required but not in this present thread.
As for Shaw's reasoning for its choice of potential channels, I agree with the assessments here.