On July 1, 1986 CKDA made the move from 1220 to 1200, and got a power increase to 50,000 watts. I don't know what their pattern was like towards Seattle, but the signals was great in Vancouver on 1200. It was decent on 1220, but the change was noticeably for the better. Where I lived in Tsawassen, they were as strong as LG73 and a bit better than AM 1040. There's audio of the frequency change online, but It was taken from quite a distance away. When they made the switch, they actually did a live broadcast from Vancouver as part of it.