There's a note on the "big yellow board" at sowny.ca about American Top 40 airing on CKOC and then a string of replies including the moderator, Craig Smith, mentioning the Canadian Top 40 circa 1974.
I don't remember that countdown. But it reminded me of others that I do remember.
The Weekly Music Magazine with Greg Haraldson (aired Saturday mornings on CKXL in Calgary and then on Sunday nights on CHED in Edmonton and CKLG in Vancouver). Remember it running in the early '80s.
In the mid-'80s, the Canadian Countdown with Russ McCloud (I think it aired on a weeknight live from CHUM in Toronto). CHED and 'XL both carried it. But CHED's feed always sounded like the reverb was cranked too high.
And in the late '70s Ken Connors hosting the Big 40 Countdown Saturday afternoons on CHED.
Anybody else?