That’s correct. Omitting -T trunk.tsv is a handy tool to determine the NAC as they are seldom found on Radio Reference. All you need to know to get started is the active control channel frequency to plug into the scope.py or rx.py command line. The trunk.tsv must contain the correct P25 System NAC else rx.py will error out and not remain running. You’ll see what seems to be a frequency error if you have stderr logging enabled on the command line. This appears to be a bug in the software, so beware if you get strange errors reported when you engage the -T trunk.tsv on the rx.py command line. I don’t know if this bug presents in scope.py but I am about to test that shortly. Bill William G. Becks, WA8WG N7027 Shady Lane Circle Porterfield, WI 54159 Telephone: 715.735.0131 Email: <mailto:wa8wg@centurytel.net> wa8wg@centurytel.net From: op25-dev@yahoogroups.com [mailto:op25-dev@yahoogroups.com] Sent: Saturday, August 5, 2017 6:31 PM To: op25-dev@yahoogroups.com Subject: Re: [op25-dev] OP25 for noobs by a noob (long) If you run without a trunk.tsv file, about the only thing that scope.py will do is continuously print out the NAC in the console window, and only then if you have the system tuned accurately. Once you know the NAC and control channel frequency you can build your trunk.tsv file and modify the scope.py command line (adding "-T trunk.tsv") to get it trunking properly.