JCAR is integrating digital modes into our weekly ARES net, and possibly into a separate digital net in the future. Digital modes are already used by emergency organizations to send and receive files, location information, emails, and more. It sounds complicated, but with a little help and familiarization, you’ll be decoding digital data messages on your computer in no time. This guide will not show you how to transmit digital modes.
NOTE: This guide is only for Windows 10 users. Also, for anything involving a web browser, I’m only using Firefox. Most of the steps in other browsers, other Windows versions, MacOS, and GNU/Linux are the same, but I can’t cover every possible variation in this guide. Reach out to info@jcar.us if you become impossibly lost and we’ll do our best to help.
The first thing you need to do is download a program called fldigi. The website for this program is http://www.w1hkj.com/files/fldigi/. There’s a lot to choose from here, but you’ll want to find the file that ends in setup.exe. The number before setup.exe will change as new versions come out. That’s okay.
You’ll see the file in your web browser’s downloads section. Click on it to run it. Windows may complain about running it. If at any time you aren’t comfortable telling your computer to install a program, don’t install it. You’re responsible for what happens to your computer, not me. There’s your disclaimer.
If you want to install fldigi: You’ll have to click “More info” to get access to the “Run anyway” button. Click that. Then, click “yes” in the User Account Control window. Likewise, click “Continue” in the Setup window.
There’s no need to change any of the installation options. Click Next.
There should be no need to change the installation folder. Click Install.
Congrats, fldigi is installed. Click Close.
Tap the Windows key or click the Windows icon in the bottom left. fldigi will be at the top of the “recently added” programs in the top left of the menu.
If Windows Defender complains about fldigi’s network access, take a deep breath. This is normal, because flgidi uses network protocols to talk to logging programs. This isn’t important right now, but if you think you’ll ever use fldigi for transmitting digital modes in the future, make sure both boxes are checked then click Allow access.
There’s not much to do here. Click Next then click Next again.
Make sure PortAudio is checked. This should default to your computer’s internal speakers and mic. This is how you’ll be able to decode digital modes without a special interface. Click Finish.
Welcome to your first look at fldigi. There’s a lot to take in! Don’t worry about it. Take a deep breath. All you need to do is click the square in the top right to maximize the screen. There should be some blue in the black area at the bottom, and it should respond to noise from around you. Whistle, speak, cough, whatever, and see if the black area reacts to it. If not, stop. If fldigi can’t pick up your audio, you can’t continue without help.
Head up to Op Mode in the top left, go down to MT63, then go down to MT63-2000L and click to set the mode.
Hover over the black/blue area with your mouse, and ensure the thin yellow line in the center is under the 1500 mark. It doesn’t have to be perfect, just pretty close. Click.
The number with arrows on each side should be 1500. If it’s not, use the arrow buttons on each side to get to 1500.
Go to the very bottom right corner of fldigi. You’ll see a slider. Slide it down to the very bottom. You’ll start to see garbage characters come across your screen, and a little green show up in the bar next to the slider. Slide the slider up just a tiny bit until the bar has no green and the garbage characters stop. This makes sure you only decode actual MT63 transmissions.
Head up to the top right and click RxID. This will help fldigi change to the correct mode when it hears a mode ID transmitted. This is not strictly necessary, but a helpful feature.
You’re ready to decode digital signals! But wait, you don’t have a handy supply of MT63 signals lying around? Say no more, I have you covered. Head over to https://www.sigidwiki.com/wiki/MT63#Samples and find the last sample on the right, labeled MT63-2000L. Make sure your computer speaker volume is up at least halfway. Click the play button, and your computer should start playing some digital noises. Your computer’s microphone should hear it, and fldigi should decode it. If it doesn’t decode, don’t worry! Reach out and we’ll help you fine tune the setup.
That’s it, hopefully you’re ready to decode digital signals. If not, you’re probably most of the way there, and it’s likely some small issue we can help you fix.
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