If you want to receive communications from the Phoenix Regional Dispatch Center, which covers most of the Central and West Valley, the sites of the Regional Wireless Cooperative (RWC) are:
Simulcast B covers the City of Phoenix.
Simulcast C covers the City of Chandler, the community of Sun Lakes and the Town of Maricopa.
Simulcast F covers the City of Tempe and the Town of Guadalupe.
Simulcast G covers most of the West Valley cities.
Simulcast H covers the City of Scottsdale.
Simulcast J covers the City of Buckeye.
(There is overlap of the coverage areas. If you're in Tempe, you should be able to hear simulcasts B, C, F, and H, even though Tempe isn't the primary coverage area for B, C and H.)
All of these simulcast systems carry the K-deck and L-deck talkgroups. You will want to program in any and all simulcast sites that will cover the areas of the Valley that you will be in.
Be aware that many listeners have issues due to multi-path interference that is common with simulcast systems. You may not be able to receive anything without a directional antenna in a base station setup. The Uniden scanners are supposedly a little better at receiving the simulcast systems than the GRE/Whistler scanners are.
It should also be noted, that the Thompson Peak IR site, located in north Scottsdale, carries K-deck 2, as well as the L-deck talkgroups when they're active, such as during the recent golf tournament.
The Towers Mtn IR, located in Yavapai County, north of the Valley, helps to cover the City of Surprise, as well as the North County Fire and Medical District (Sun City West, Wittmann, and adjacent unincorporated areas), and carries K-1 (dispatch) and K-6 (Northwest Valley EMS responses) on a regular basis.
The simulcast and IR sites of the RWC system carry the EMS responses. K-6 through K-9 are used for typical EMS calls. K-10 through K-15 are for mountain rescues and major incidents such as roll-over accidents and those requiring extrication. Most comms for the typical EMS responses are handled by the MDC's in the apparatus, such as responding, on scene, enroute to the hospital, available on radio, and available in quarters. You may hear a request for an ambulance/rescue/medic unit if one wasn't on the initial dispatch and is needed. Mountain rescues and major accidents have much more voice activity.
If you want to hear the fire and haz-mat responses, you want to listen to the analog VHF channels.
If you want to receive communications from the Mesa Regional Dispatch Center, which covers Mesa, Gilbert, Apache Junction, Queen Creek and Rio Verde, you want to listen to the TOPAZ RWC, which has one simulcast system (the Mesa simulcast) and two IR sites, one on Thompson Peak (separate from the Phoenix site) and one on Shaw Butte in Phoenix. From personal experience, the IR sites don't carry comms from the apparatus/portable radios, just the alarm room. You may have to listen to the simulcast system for both sides.
Mesa carries both EMS and fire/haz-mat comms on the TOPAZ RWC. Other than their dispatch channel of 154.340, I don't believe their VHF channels are in use like Phoenix does.
Rural/Metro, Inc is the 3rd largest fire department in the Valley. They cover the towns of Carefree and Cave Creek (north of Phoenix and Scottsdale), Litchfield Park and unincorporated areas of the West Valley not covered by a fire department or district dispatched by Phoenix, unincorporated county islands in Mesa and the East Valley, the San Tan Valley area of Pinal County south and east of Queen Creek, and they dispatch for Fountain Hills as well.
Other small FD's include Luke AFB in the West Valley, which is on it's own 400MHz P25 trunked system. The Salt River Indian community, which is on it's own P25 Phase II trunked system. The Gila River Indian community, which is on it's own P25 Phase II trunked system. The Ft. McDowell Indian community, which uses the TOPAZ RWC system (Thompson Peak IR). The Tonto Hills FD, a community adjacent to Cave Creek, which is on 159.360. And the Circle City-Morristown FD, at the junction of US 60 (Grand Ave) and AZ 74 (Carefree Highway) between Surprise and Wickenburg in the far Northwest Valley, which is on 158.7525.
Outlier FD's include Wickenburg in the really far northwest Valley, and Black Canyon City, on I-17 just across the Maricopa-Yavapai county line well north of Phoenix. They're in the DB if you find yourself in those areas.
I think that covers everything.
John
Peoria