Can you give a little more detail about what your hearing , is that scanning frequencies manually , or trunk tracking , and what does it sound like? I listen to Pasco all the time in "Open" mode and i have never heard any encryption. I would guess that if anything Pasco has some pro-voice talkgroups but no one has ever confirmed that and i have never heard any digital noise scanning their freq.
When penny for pasco was extended one of the things they said was to come from that money was digital radios but not sure if that was for current system or a new system. If those radios are for the current system then i would guess they could possibly have some pro-voice talkgroups, their system is similar to hillsborough and hillsborough has pro-voice talkgroups.