So If I'm in Sackville listening to the trunked system from the Sackville tower, does the local Sackville tower rebroadcast the stuff that isn't being transmitted locally (IE within range of my receiver) or will I only receive the radios within range of me?
If it doesn't rebroadcast stuff what's the best setup for two SDR's to get the most traffic? Should one be on the trunk with SDRtrunk and the other scanning the VHF freq's on SDR#, or should I do something else?
I think the easiest way to explain trunked radio would be an example. You're scanning the Sackville site. Let's say there's a fire in Cole Harbour, and HRM fire assigns the 'ops 2' talkgroup for the fire. The site with the best coverage in Cole Harbour is most likely the Preston site. Everybody on-scene in Cole Harbour switches their radios to ops 2, and lets say everyone's radio affiliates with ('attaches to' if that makes sense) the Preston site. If every radio on ops 2 is affiliated with the Preston site, that's the only site you'll hear ops 2 on.
Now let's say the district chief responsible for the Dartmouth and Sackville areas happens to be out in Sackville at the moment. He switches his radio over to ops 2 so he can monitor, and at that point you'll hear ops 2 on the Sackville site (in addition to Preston). But if he turns his radio off, or switches to a different talkgroup, or goes out of range of the Sackville site, then you'll stop hearing it.
Hopefully that helps understand how trunking works. You're only going to hear a certain talkgroup on a certain site, if there is at least one radio that is affiliated with that site and monitoring that talkgroup.
As for your second question, I think it's always a good idea to at least monitor the VHF paging frequencies, since that's just about always going to be the initial call-out. You don't need to monitor all of the frequencies listed in the database, where you're at you would only need to monitor 151.4 and 152.18 and you should hear everything in HRM.