[FedCom] Freq Help

[MJ Cleary]

Hi all,

Today I found a freq that wasn't found active before in numerous searches. Freq is 172.075 MHz with Tone of 167.9.
Traffic is mostly encrypted with one side in the clear sometimes. Callsigns heard were ECHO 1 and ECHO 3 and there was a clear transmission: "How was the airport?". Only other clear ones were radio checks. Answer was encrypted. My QTH is Charleston, SC. 

Also found 172.050 MHz to be active this morning with two females in the clear one upstairs and one in a basement troubleshooting inoperative phone lines on their computers. They ended up calling Sprint.

Ideas?


Mark