Max, I now have excellent audio using netcat & aplay with the zero center frequency in trunk.tsv and the sampling rate –S 1000000 in the rx.py command line. Still no sign though of sockaudio ever starting up. Thank you! Bill William G. Becks, WA8WG N7027 Shady Lane Circle Porterfield, WI 54159 Telephone: 715.735.0131 E-Mail: wa8wg(a)centurytel.net <mailto:wa8wg@centurytel.net> *From:*op25-dev@yahoogroups.com [mailto:op25-dev@yahoogroups.com] *Sent:* Wednesday, July 5, 2017 6:24 PM *To:* op25-dev(a)yahoogroups.com *Subject:* RE: [op25-dev] Re: sockaudio.py startup? Disregard my previous message. I had to reinitialize the SDR and rx.py now loads with a zero center frequency in trunk.tsv using the lower sample rate as suggested. Bill William G. Becks, WA8WG N7027 Shady Lane Circle Porterfield, WI 54159 Telephone: 715.735.0131 E-Mail: wa8wg(a)centurytel.net <mailto:wa8wg@centurytel.net> *From:*op25-dev@yahoogroups.com <mailto:op25-dev@yahoogroups.com> [mailto:op25-dev@yahoogroups.com] *Sent:* Wednesday, July 5, 2017 6:08 PM *To:* op25-dev(a)yahoogroups.com <mailto:op25-dev@yahoogroups.com> *Subject:* RE: [op25-dev] Re: sockaudio.py startup? I tried setting the center frequency to zero in my trunk.tsv and turning the sampling rate down but rx.py doesn’t like the zero center frequency. See below. Where can I download the patched version that allows a zero center frequency statement? *pi@raspberrypi:~/op25/op25/gr-op25_repeater/apps $ ./rx.sh* *linux; GNU C++ version 4.9.1; Boost_105500; UHD_003.007.003-0-unknown* ** *setting gain lna to 49* *set_center_freq: 0* *./rx.sh: line 2: $'\r': command not found* *./rx.sh: line 3: $'\r': command not found* *./rx.sh: line 4: $'\r': command not found* *./rx.sh: line 5: $'\r': command not found* *./rx.sh: line 6: $'\r': command not found* *./rx.sh: line 7: $'\r': command not found* *./rx.sh: line 8: $'\r': command not found* *./rx.sh: line 9: $'\r': command not found* *./rx.sh: line 10: $'\r': command not found* *./rx.sh: line 11: $'\r': command not found* *pi@raspberrypi:~/op25/op25/gr-op25_repeater/apps $* Thank you, Bill William G. Becks, WA8WG N7027 Shady Lane Circle Porterfield, WI 54159 E-Mail: wa8wg(a)centurytel.net <mailto:wa8wg@centurytel.net> *From:*op25-dev@yahoogroups.com <mailto:op25-dev@yahoogroups.com> [mailto:op25-dev@yahoogroups.com] *Sent:* Wednesday, July 5, 2017 4:03 PM *To:* op25-dev(a)yahoogroups.com <mailto:op25-dev@yahoogroups.com> *Subject:* RE: [op25-dev] Re: sockaudio.py startup? yes, though it depends on whether a center frequency has been specified. If so then OP25 remains tuned to the center frequency and if not, it retunes the SDR each time a frequency change is needed. From what I've seen the slow sample rate (250,000) on the PI causes the changes to be somewhat slow, so I was getting the first word(s) of calls chopped off. Currently (for the PI) we recommend -S 1000000 and setting the center frequency to zero, or omitting it. Another user reported getting a crash with this, and a possible workaround for it has just been pushed to the repo.... It should be possible to set the center frequency to zero. When this is done the trunk-tracking mode should work fine no matter how wide the system is, but it does preclude the use of the log-all-talkgroups-to-disk mode, unfortunately... Max

it's a silly historical artifact of OP25 that when -T is in use the CC frequency is taken from the trunk TSV file, but you still have to give a valid (dummy) frequency on the command line with the -f parameter. As far as the trunk TSV there is the trunk control channel frequency (or a comma separated list of CC frequencies), and separately there is the "center" frequency. I recommend setting that to zero (unless the log-all-talkgroups-to-disk mode is being used). Likewise use "-S 1000000", unless the logging mode is being used. Max