755t and 750.

[Ron B]

the 750 can hear the 755t but the 755t can not hear the 750. I have tried evenrthing I can think of

 

[Nuvi-Nebie]

I am guessing you are referring to the two way radio feature of the Garmin Rino 755t and Rino 750

You haven't supplied many details to work with, eg:- do the units work OK when close to each other but not at a distance ?, have you tried different channels ?