One is only able to set up a good feed if the scanner is relatively near to the transmitter in question, or all you'll get is transmissions from aircraft at altitude.
Both Moncton feeds are too far away from SJ and FC to pick up anything. If you have the equipment, and live near the airport try contacting the site admin (Dave), I'm sure he could help you set up a feed.
By the way you'll get some traffic from YYG radio (118.0) on the Moncton Centre feed that's in Charlottetown. The scanner scans a rather big selection of frequencies, so the transmissions may be cut off by traffic on other frequencies.
S.