I have never heard any voice on 220-222 MHZ in North-Central
Oklahoma, but I do hear continuous data transmissions that have
occasional CW ID's.  I think these are what they call SCADA systems.
That stands for Supervisory, Control And Data Acquisition.  Not
terribly exciting to listen to.  All of these signals are faint, here,
but get a little louder when the band opens up.

        I have no idea where they are coming from except that they are
not local.  I am 50 miles North of Oklahoma City, about 70 Miles
Southwest of Tulsa and about 120 miles south of Wichita.

        SCADA systems are used anywhere one has lots of remote
monitoring such as oil pipe lines, electric power distribution
systems, water treatment plants and so forth.

Martin McCormick WB5AGZ  Stillwater, OK
OSU Information Technology Division Network Operations Group