<snip> Second issue: The loudest playback sounds cause the URI to go into saturation and distort. I may not have calibrated the levels very carefully, but even if I manually lower the txlevel setting from 800 down to, say, 300 it still distorts - it's just a quieter distortion. What can cause this? <snip> I have the same problem with a modified CM108 usb installation. After setting all the 'radio tune' parameters, there is serious distortion on voice modulation peaks, irrespective of the source being Iaxrpt or another node. However, the 'radio tune txvoice' generates a perfect sine wave at 3 KHz deviation, as seen on an oscilloscope at the exciter modulator or on a service monitor off-air. I am using duplex=0 in rpt.conf since the node operates simplex. Dave VE7MQ 2140