ah - so that’s a good clue - the radios that work duplex - I’m assuming that whoever is on the other end of that is able to talk to all the radios in both models and hear them?
In simplex mode the most likely thing is the sub audible tones, so remove tones from two radios, one of each type and see if comms is then enabled - if it is, you have a tone mismatch of some kind - you could then try using a conventional CTCSS tone instead to tie the fault further down - if using say 98.4 works properly then the issue is with the D encoding/decoding. If on the other hand, disabling tones produces no sudden burst into life, I’m thinking maybe it’s a bandwidth/filtering issue. Icom had this on the old H and U 16 radios when they were mixed with radios with higher deviation. The excess deviation triggered a receiver mute - it was usually impractical to solve this with mods to one set of radios.
The two questions again.
- on the duplex channels - can the person talking to all the radios hear and talk to them all?
- with tones totally disabled, can they talk between models?