After reading Guy's (K2AV) excellent explanation of measuring the K2 keying waveform with Spectrogram, I decided to make the measurements myself, using the ICOM IC-746PRO as the measuring receiver, and transmitting into a dummy load with about 50 watts. The Spectrogram plot of this test can be viewed at: http://64.105.107.250/kqrv/k2keying.aspx 73, Dale - wa8sra