This may be the COR (carrier-operated relay) cutting in because of the strong signal level. I have experienced the same thing on 40M. 73, Doug Fleming KF4VTT K3#1289 P3#371 -- View this message in context: http://elecraft.365791.n2.nabble.com/P3-click-click-tp5771758p5771836.html Sent from the Elecraft mailing list archive at Nabble.com.