I would think that the lower stack on channel 3 will continue in operation until Aug 31 2011 when it will be dismantled. I imagine that the power is about 50% of the original ERP 300 Kw at a lower EHAAT (a fraction of it's former glory). The old Hi band stack will also be removed after the switchover date I would think, unless it can be used as a backup antenna? The Channel 3 transmitter is a Larcan 30 Kw M series unit the same that Calgary is using at present on Channel 2 but they had a whopping antenna gain when both stacks were in use.
In Calgary. a new stayed mast has been erected by Harvard broadcasting for their FM use on the Global TV site but it also was fitted with UHF panel antennas on-top 378 Meters EHAAT. The old original Channel 2 mast was becoming dangerous as it suffered various effects due to stress possibly caused by weather conditions and so it has been taken down. The new CICT-DT transmitter on channel 41 should be on the air any time now! Rogers is also sharing the new installation with it's CityTv and Omni channels. CFCN already have a new UHF stack on the top of their newer tower (2001) and have received CRTC approval for their 10 Kw transmitter producing 220 Kw ERP on Channel 29. I am waiting for a timeframe for their switch-on.