Generally speaking:
K-6 Northwest Valley
K-7 Northeast Valley
K-8 Southeast Valley
K-9 Southwest Valley
K-10/11/12 Mountain rescues and multi-patient injury accidents.
K-13/14/15 I'm not sure how these are assigned.
Each deck in their radios should have 16 channels. I don't know that a K-16 has ever been identified. I was once told it was used by fire inspectors, but I don't know if that is accurate, nor do I know what the TG may be.
I-17 and Northern Ave are roughly the borders between East & West, and North & South.
K-2 is for small special events and some special details, as well as Central City, which is an alcohol recovery program that the RDC dispatches for. K-3 is also for special events, and special details.
K-4 and K-5 are encrypted. They are used for sensitive incidents and operations, such as medical standby when the POTUS or other high rank VIP is in town, or when assisting the PD on certain calls.
Each department and district under the RDC has its own set of K-2 through K-5 talkgroups, in addition to the main Phoenix ones. Glendale's K-2 and K-3 are in the database. I think I've heard North County (back when they were just Sun City West) on their K-2 as well. You may hear things like hydrant testing or building inspections on those K-2's and K-3's. Not all of the other K-2's through K-5's are in use, although each department/district has them assigned, or at least reserved.
I'll see if I can find the thread that linked to a map for the A-deck assignments. However, roughly:
A-5 is Northeast;
A-6 is Northwest;
A-7 is Tempe;
A-8 is Downtown and South Phoenix, and Ahwatukee;
A-9 is Southwest;
A-10 is Daisy Mtn. (New River and Desert Hills areas);
A-11 is Scottsdale;
A-12 is Chandler and Sun Lakes;
A-13 is Tonopah and Harquahala Valley;
A-14 is supposed to be for Haz-Mat sector use, but I've never heard it used;
and A-15 is for car-to-car use. I think I heard a building inspection being conducted on it last year. The RDC alarm room does not have transmit or receive capability on this channel.
A-16 is the same as A-1.
A-2 is for special uses. (I once heard a bi-lingual dispatcher/tactical radio operator, or TRO, facilitate a translation when the firefighters gave a Spanish-speaking family member of a patient one of the radios, and the dispatcher asked them the questions the medics needed to tend to their patient, and then repeated the answers back in English for the medics.)
A-3 seems to be an overflow fireground channel, particularly when A-8 or A-9 are already in use. I typically have heard incidents between the Downtown area and the Maryvale area assigned to this channel. It doesn't seem to be frequently used, however.
A-4 is interoperability VFIRE-21.
As mentioned previously, if two incidents in the same geographic area both require a dedicated channel and TRO, one of the incidents may be assigned to a different channel than it would be normally. So, a 2nd incident in the Northwest Valley may be assigned to A-5 or A-9 if both incidents need a dedicated channel.
John
Peoria