I am new to RTL-SDR radio scanning bought it two days ago. I Purchased the RTL-SDR bundle using the longer whip and I am having slight problems receiving dispatch transmission from local police. I have properly installed SDR# and and currently running DSDPlus with one dongle. I have been able to decode the officers transmission very clearly, but when it come to broadcasts from the dispatch I get a message "voice muted due to encryption". I am out of Alabama, Walker in specific. Radio reference lists the channel as 155.550 its a P25 FM station. Without any indication of encryption or trunking. Any advice would help thanks.