Hello Scott, Thanks for the pointers, I cleaned up the trunk.tsv files and added the suggested values; I also removed that blank line in the cincy.tsv file and, using the command line as stated, the Graph came up and displayed. Great progress, at this point, the display in the terminal windows is scrolling "timed out". I was able to use the PPM correction (20) to adjust display to read "Tuning Error" +/- 2400 and then down to - 1200. At PPM setting of 18, the terminal read, +1200. At -19 PPM, the displayed stopped scrolling and, my Constellation appeared to be as desired; "Fine Tuning" in either direction would cause a tuning error. All good until I went to the "Traffic" tab, there were zeros in all the fields ( "rf:syid, rfid, stid") where there should have been numbers, It appears that I can see the traffic and tune he frequency but, I am not breaking the squelch(?) or do not have the correct NAC(?). BTW: I heard only one snippet of audio during the process, so, with everything seemingly to be in the ball park, what key attribute am I missing, is it the correct identifier for the Cincinnati / Ham. Co branch of the Ohio MARCS-IP system or, is it an intellectual thing? Thanks again for getting me oriented, all help is appreciated! Mel

Scott, I am using the NooElec NESDR Mini for the op25 receiver. The first device that I bought was a cheaper one and then I bought a higher priced NooElec Mini to use with Unitrunker, the NooElec device has a lower noise floor and, it does not drift as much over time as does the cheaper model. To build my op25 receiver, I started with the RR forum article (circa 2014) on running op25 on Windows 7 on VM Ware. I decided to create a bootable a USB stick with GNU Radio Live SDR Environment running on Ubuntu 14.04. After establishing Ubuntu, I went back to the RR forum and used the PYBOMBS install script: Install the OS(assuming Ubuntu or Mint), then open a terminal session and Code: sudo apt-get install git sudo apt-get update Reboot if it asks, otherwise type the following: Code: cd ~/ git clone git://github.com/pybombs/pybombs cd pybombs ./pybombs install gnuradio So, at this point I have it installed but, I continue to read more until I came across, This recipe has been tested on ubuntu 14.04 only, it is likely NOT to work in either 12.04 or 16.04... First, use these commands to install the pre-reqs sudo apt-get update sudo apt-get build-dep gnuradio sudo apt-get install gnuradio gnuradio-dev gr-osmosdr librtlsdr-dev libuhd-dev libhackrf-dev libitpp-dev libpcap-dev git Second, use these commands to build and install OP25: [Note, the mkdir build; cd build; cmake ../; make; sudo make install sequence is a bog-standard form when source-building apps that utilize cmake.] cd ~ git clone git://op25.osmocom.org/op25.git cd op25 mkdir build cd build cmake ../ make sudo make install sudo ldconfig So Scott, after I installed and understood it, I started working with the trunk.tsv and the cincy.tsv to make it work for me. That's when I got you involved. Mel