I have modified TCube and just uploaded it to : http://www.weaksignals.com/bin/tcube_092.exe It now has a pushbutton labeled "I/Q Mode" When pressed, the left and right channels are locked to the same frequency, and the right channel outputs a sine wave delayed by 90 degrees wrt the left channel. Hope it can be useful for experiments on the phasing exciters. 73 Alberto I2PHD