Exactly what is happening. Thanks!In the RadioReference database, if control channel data indicates that the system can use P25 Phase II, it's tagged as Phase II.
However, many Phase II capable systems are set up to allow P25 Phase I transmissions as well. If someone with an older radio (portable, mobile, whatever), that can only use Phase I, is affiliated with the system on that talkgroup, the talkgroup transmissions will be handled as Phase I. However, if there are no "Phase I only" radios affialted, then the talkgroup conversations will be strictly Phase II.
thanksP25 is P25. An old P25 "subscriber unit" will work on a modern P25 system. Likewise, a modern P25 "subscriber unit" will work on a P25 system that is not up-to-date. It's a standard. That's why they made it.
Whether your scanner can keep up is a different issue.
My understanding is that if a single radio on a talkgroup is incapable of TDMA, all radios on that TG just drop back to non-TDMA and life moves on. Eventually, those radios will go away. This isn't like the 1970s or 80s where you could have the same radio for 20 years - this is capitalism.