Ok, so first, P25 conventional is in no way analog. It’s a completely digital (and standardized) protocol, unlike ProVoice or aegis.
There is a squelch adjust on the 100M, you just need to make sure it’s in the menus list or on a hot key. How are you programming the radio (p25c set with some analog channels mixed into the p25c, or two different sets, one for p25 and the other for analog)? Where is you speaker connected (remote head, radio mounted head, HHC, etc.)? Did you make any cables yourself, or is everything an OEM part?
-B