I notice a lot of different threads here about how much power is proper for this mode, or that mode. I have a general rule of thumb to stress concerning ALL the soundcard generated digital modes. It has been mentioned in other threads, but seems to be overlooked, or perhaps different operators think that it should be different depending on what mode one is attempting to operate. If your digital signal is being generated by your soundcard, and you are using the audio stages of your rig to create the RF suite of frequencies that will be turned back into tones and decoded by the software at the other end, is is always BEST to adjust the power of your rig for MOST LINEAR output, with NO ALC action being generated in the radio ! ! ! This is almost a CARDINAL RULE for digital transmissions. If you are using a commercial interface, adjust the gain controls on it to somewhere around the 1/2 to 3/4 position, but not fully on. Turn the RF level up full ( except in a few rare cases with some specific radios ), and advance the soundcard gain until you barely see SOME ALC, and then back it off just the slightest amount. This should give you a fairly high level of RF output, and everything should be operating in the linear region. You shouldn't see any problems, and the receiving station should see a pure signal on his/her waterfall! I repeat, this should apply no matter WHAT soundcard signal you are attempting to transmit, PSK, Olivia, Baudot even keyboard generated CW, DRM and the "analog" types of SSTV. Hope this helps!