At 06:07 PM 2/12/2004, you wrote: >Dexter McIntyre W4DEX wrote: > > > > Have I heard my first PLC? If so it sounds flaky to me. > > > > Recorded between 1800 and 1830Z 12feb04 on 186 kHz with loop NW/SE: > > > > http://w4dex.com/temp/186khz12feb04.wav > > > > Dex That does sound strange... What ranges are PLC's usually found on LF? What do they do with this tone besides turn it on & off at different times?