AFAIK, in the Phoenix metro area, 2-tone paging is rare.
Phoenix Regional has used a few for a few specific units, but they're rarely used outside of the 7am pager test, or when announcing a multi-alarm incident that is already being worked.
Rural-Metro uses DTMF tones for dispatch, I believe.
I think Mesa Regional is the same as Phoenix.
I'm not sure about the Ft. McDowell, Salt River, or Gila River community FD's.
Circle City-Morristown FD uses a single tone.
I haven't heard Luke AFB FD, or Tonto Hills FD in quite awhile.
John
Peoria