If I use pin 8 on the URI (active low) and connect it to P5-17, or P5-20 (COR & CTCSS both Active High) on the Mastr III backplane, the URI goes into a broadcast storm. Using any of the optional pins for COR (2 & 3 both listed as active high) nothing happens. I suspect since these are GPIO, the configuration (for the URI?) is incorrect.
I know the URI works, as I was able to use it to drive an XPR5550e programmed to the analog frequency of the Mastr III. It's just not the best situation to run it like that. You clearly hear dispatch, but since I'm not tapped onto the return path of the antenna connected to the Mastr III, the mobiles response clarity is dependent on the proximity to the antenna of the XPR5550e.
"Double check your programing too, as the Mastr III IO is based on programing.
You'll need to ensure you have your de-empahsis and pre-emphasis setup
properly too."
I do not have the Mastr III programming software (and can't seem to find it anywhere). Another user in this list says he has it, but it searching for it. So, I have no idea how it's programmed. It's possible the backplane connecters for audio out are disabled?
Thanks for your help.
--Bret Taylor
Olympia School District