SDR Trunk Linux & Win 7 OS Setups
W4KRR, you will likely need at least three RTL-SDR sticks, the spread is too far, you're 100% correct. You need a full 6 Mhz range, so that will be 3 cheapo SDR sticks, or you'll be swearing. I need two for my near 5 Mhz freq spread, but I don't use over a 2.4 Mhz Sample Rate, I didn't have good luck.The second SDR stick+ is automatically "found" by the program and they set themselves after you get the first one working. But don't mess with the frequencies in the Tuner fields, the program itself does that for you. I run them with the small mag mount antennas (included with some SDRs) on top of my scanners and set Master Gain (Tuners field) for "Automatic" setting for the first one. With two sticks, they set themselves and you can't mess. Works fine in my basement like this, just on these small antennas. Works better than my scanners do on P-25 like that with better antennas too. Denny Built a better (RF) mousetrap. Says a great deal about his program.
I also had to switch the decoder in the Decoder/Modulation fields. I ran P-25 Normal C4FM and I got nothing much in the Details field under Now Playing. Not updating Events field much. I had to use Simulcast (LSM) mode in order to fix it, then it worked right. I also need to click on the actual Control Bar/P-25 Decoder field in the Now Playing area, and click on the Tuner in the Tuner field to get it all rolling right. After various setups, you will need at least a 4 core processor, or it will bog and put the calls into a time warp. On an I-3 (2130) low end PC I use about 10-20% of the CPU now. But it will just bog down on a standard Dual Core PC. It ramps up to use about 1-2 Gig of Ram over base ram and if you check on the logging boxes, prepare for Gigs of log files.
Well, I have more info from days of various OS installs. The Open JDK Java 8 or 9 (Linux versions) seemed to be iffy. I tried a few times with Open JDK 8 and 9 (headless) in the Ubuntu Mate Synaptic repos and the related files, and while it said Java was installed, the program wouldn't start for me. I used Synaptic and uninstalled both, then re-installed just Open 8 JDK, but it seemed confused. Said that Java was installed per my query. This was on a pure Ubuntu Mate PC. I then just got the real IBM/Java 9 version, (you have to tick the legal terms box too) and the thing just worked. On another Linux Mint (Rosa) computer, it works perfect using Open JDK Java 7 runtime. But I did run into issues everywhere with the installs, even on a few Windows machines. Works best to follow Denny's instructions. I did have it running on a Linux laptop and could not get P-25 decoding working after hours of various file re-do's, just NBFM. My error was that I didn't get the "Ant" program after Java and run that "Ant" command. So it couldn't compile the JMBE files and the batch download would error out. I had just copied the JMBE folders from another Linux install (thinking that would work) but it never compiled it. But first, you have to install Java (the JDK vers), and add it to your environment variables and a have a ref to it in your Path field (Windows) or the next steps won't work either, and you will get confused. Next you must install the "Ant" program in either OS, or you will also get a different error message in the Denny's JMBE download. If Java was installed right and "Ant" was installed right, it will do the JMBE compile (takes about 20 secs, in a terminal window while on the internet) and it should work in either OS. Wait for that to finish. I didn't have to add Java to my Linux bash file, but in Windows, yes it has to be added to the Path string at the end.
The Windows (7 & 8.1) boxes always will always fight with you with the RTL-SDR proper driver issue. I used Zadig, but a few times I had to reload those drivers a second/third time as Windows Lost its mind and said it had a "Unknown Device" a few times when I tried to plug in a RTL-SDR stick. And don't jiggle it! Then Windows will unload the driver for you! (Ahh, Windows) You need the driver loaded for each "Bulk Interface" stick you plan to use and even if you're using a USB hub, reload the Zadig driver for that RTL stick on that USB 4 port hub too. You need to plug them in before you open the SDR Trunk program. If you don't see a Tuner listed to use, Windows isn't finding your RTL-SDR stick! Reload the Zadig driver. Again. Unplug/Replug the RTL-SDR stick. In Linux Mint & Ubuntu Mate the drivers load automatically, but I did have the GQRX program installed first on each one of these Linux installs, so that program's files might be helpful in Linux installs. I did have a problem with finding the Ant executable file, in Windows, and you Must install the "Ant" program first per directions (after you install Java) or the next steps won't work either. In Linux, I just used Synaptic and asked to install "Ant" and then the rest of the steps worked. But I had put various "Ant" files all over various directories in Linux. Follow the directions, makes life easier. It is an Incredible program, once setup in any Linux distro or Windows. A complex setup, but so worth it. The P-25 Audio decode is flawless. Da Man Is A Total Genius.
