I know is an old thread but it might help someone else someday:

I would imagine that analog's CTV and CBC in montreal are located in the VHF band , ch 2 to 13, and this is an UHF antenna ch 14 to ch 69 therefore it has poor performance on the VHF band. The tall trees does not help neither.

The indoor , probably a rabbit's ears , on the contrary, is designed for VHF so it will perform better on the CBC/CTV analog.

Double check your TV has a digital tuner and then re-scan looking for the CBC and CTV UHF digital versions. If you post your equipment maybe we can help you further.