I'm seeing the same issue on the Phoenix RWC P25 PH1 simulcast a with my 436. I can literally see the tower from my desk at work and reception is typically pristine (rare for a scanner on simulcast). However lately I have noticed periods of hours at a time where there is nothing....no signal bars, no transmissions received. I only have the control channels entered so putting all frequencies in is my next step, but I sure hope that's it.
Update: All frequencies (not just listed control frequencies) entered in the CC table, still not a peep from one of the busiest PD's in the country...something is very wrong. I would honestly rather it just be the scanner than what I fear it might be....an unannounced switch to encryption. They already encrypted all hot call TG's, and of course all tac ops and C2C and info TG's were encrypted from day one, so this might be it for PPD monitoring...sure hope not. Once I get home to turn on my G4 I'll know for sure I guess. I've posted a request for reports on this simulcast from other AZ scanner buddies, so I'll probably hear on that before I get home, and will update with what I find out.