When you are injecting into a part of the audio chain that does not require pre-emphasis, you might still want limiting. In that case, you set txlimonly=yes At one time several people reported they were getting pretty horrible-sounding clipping when the URI was driven beyond full scale. Subsequent to that I found the real problem was that when you use composite audio the software will happily attempt to generate a number bigger than 16 bits when you use gain settings for voice and tone that total >1000. The restriction that these two numbers not add to more than 1000 (for composite audio) *is* documented and is the real solution to that issue. However, it's not inconceivable that somebody might want limiting without pre-emphasis, if the limiting in the radio was inadequate. Ken From: app_rpt-users-bounces@ohnosec.org [mailto:app_rpt-users-bounces@ohnosec.org] On Behalf Of Jim Duuuude Sent: Tuesday, October 09, 2012 9:17 PM To: w7ry@centurytel.net; app_rpt mailing list Subject: Re: [App_rpt-users] USB Radio Commands It is one of those 'it really has no good reason to ever be used' options, and I have no idea why someone wanted it, but it was harmless and utterly trivial to add, so I did. It, along with a few others of those were never documented to discourage their (quite questionable) use. Jim WB6NIL _____ From: w7ry@centurytel.net To: app_rpt-users@ohnosec.org Date: Tue, 9 Oct 2012 18:05:25 -0700 Subject: [App_rpt-users] USB Radio Commands So if this setting txprelim=no is: TX audio processing. Options: (no,yes). Choosing yes turns on transmitter preemphasis and peak limiting, along with a lowpass filter. The yes option is used when driving an FM transmitter directly by injecting audio right into the modulator. The no option provides audio which should be injected into the microphone input of the transmitter or at some point in the transmitter' speech amplifier before preemphasis, and limiting. What is the setting? txlimonly=no Nothing in the manual about it. Thanks 73 Jim W7RY _______________________________________________ App_rpt-users mailing list App_rpt-users@ohnosec.org http://ohnosec.org/cgi-bin/mailman/listinfo/app_rpt-users

I changed duplex=0 to duplex=1 in usbradio.cfg That seemed to clean up the audio. Turning on the DSP, must make the audio slightly more bassy. Thanks all 73 Jim W7RY From: Kevin Custer Sent: Tuesday, October 09, 2012 6:35 PM To: Jim W7RY Cc: app_rpt-users@ohnosec.org Subject: Re: [App_rpt-users] USB Radio Commands I reconstructed the following query, as the answer to your question was already in the text you pasted. Kevin So if this setting txprelim=yes is: TX audio processing. Options: (no,yes). Choosing yes turns on transmitter preemphasis and peak limiting, along with a lowpass filter. The yes option is used when driving an FM transmitter directly by injecting audio right into the modulator. ------------------------------------------- What is the setting? txlimonly=no The no option provides audio which should be injected into the microphone input of the transmitter or at some point in the transmitter' speech amplifier before preemphasis, and limiting.