The 800 mhz RSP system is the focus but it has many small sites and perhaps two or three large ones. Which talk groups go with which sites. The Airport is easy and perhaps site 1 is tied to the adjacent cities talk groups. Is there a list of the associations of sites to groups ?
Site #1 is the main site to listen to.. as long your guy is on the island of montreal or near the island..
site #1 will give him all of the important stuff.. Urgences Sante (EMS System).. Longueuil Fire ...The Longueuil Police is ProVoice i believe.. he will also get all of the Public Security depts (Westmount..Town of Mount Royal..St.Laurent..Outremont..Cote St.Luc..Hampstead..) The Cote St.Luc EMS 1st responders... Dorval Airport Security & Fire/Crash Rescue.. and even some of the north shore (Terrebonne & Blainville & sometimes Deux Montanges (2 Mountains)..) depts.
if he is out on the extreme west part of the West Island he might need to also enter Site #4 Pointe-Claire & Site 45 Ste.Anne de Bellevue..
I live on in Pierrefonds near the back river (north western part of the island) on need to have Site#4 installed to pick up the Pointe Claire Public Security (who also dispatches the Kirkland & Dorval Public Security depts) & the Pointe Claire Volunteer rescue unit.
i have never had the need to program the Airport Site #2 to hear them..they come in clear on site #1..
1 thing to be aware of for the Airport talkgroups.. you will see 2 T/Gs 04-151 & 04-152 for the SPVM police..you wont hear them on the scanner.. it is only a pathway/patch that conects the Airport system to the police radio system.
if you can set up that with seperate groups ..1 for Urgences Sante ..another for the Public Securitys ..and another for Longueuil that would be the best way..
I hope this is answering your questions..