radioman148 said:
Why wouldn't all news work?
One would need a full-market, preferably 50,000 watt, signal at the low end of the AM dial. There are only two of those here: KFYI and KTAR, and neither is changing formats. Neither are they 50,000 watts.
The only all-news station AFAIK at the top end was WTOP 1500 in Washington DC, owned by TMISU. It's now on FM and for good reason. Despite being 50 kW, AM 1500 (whatever it's called now) doesn't cover the entire DC metro - too directional and at the wrong end of the dial. 50 kW on 1500 is worse than 5 kW on 550.
Various stations tried it years ago: KPHX in the early '70s. KTAR in the mid '70s, KRUX in the late '70s, and KNNS in the early '90s. All failed.
Of course, there's always an FM station, which both SeeBS and TMISU have plenty of. Neither has tried. Again, for good reason. Phoenix isn't big enough, educated enough, or affluent enough (outside of Snobsdale & PV) to support it even if a decent signal were available.