A-12 is 154.1300, and covers Chandler and Sun Lakes, as well as the Town of Maricopa.
A-13 is 154.43000, and covers the Tonopah and Harquahala Valley area west of the City of Buckeye.
Go here, and scroll down to Phoenix:
Scanner Frequencies and Radio Frequency Reference for Maricopa County, Arizona (AZ)
www.radioreference.com
These two frequencies used to be Chandler FD's repeater input and output, respectively, before they joined the PFDRDC system.
The westernmost VHF-High site is the White Tanks, I believe. The westernmost RWC trunked site is now Burnt Mtn in the Tonopah/Harquahala Valley area, just west of the Burnt Wells rest area on I-10.
John
Peoria