Hi, Through trial and error, and with the help of several listening stations, I've come up with the following transmit audio settings for the Orion II, when used with the 707 Regal microphone on AM. MIC 80 TX EQ -5 dB TX Filter BW 2100 Hz L.F. Rolloff 200 Hz H/W Mic Gain 16 dB Comments, anyone? 73 Ray W2RS