Tutorials and Electronic Adventures: Connect Radio to Computer w/ Easy Digi Board and Communicate Worldwide w/ Digital Radio

Another project I've been working on and finally tasted the fruits of my (small) labor, good treat for everyone who doesn't already know how to do this and wants to. All the magic is in the soundcard and the software generating audio tones, and the radio amplifying those signals for worldwide transmission.

First you need a radio, my radio is a TS130s, which is from like the 1980s and doesn't have the fancy bells and whistles of newer transceivers of today. If you have a newer/fancier radio (they're expensive), then this won't be necessary, and you could probably just do plug-n-play. For instance, my dad's ICOM radio could connection easily via a USB COM port and not need this interfacing board at all. Essentially *zero* configuration was needed in fldigi to be up and running with this, it's plug-n-play.

This is *very* radio specific, you WILL have to modify this depending on what radio you use, if that scares you (shouldn't), then don't waste your time and get a ready made solution for you (but where's the fun in that?). You need to find the microphone pinout of that radio, and you need a microphone that plugs into the radio that you don't care about (that's what I did, just cut the microphone off and split open the cable, but note that that curly wire is a major pain in the ass, and the damn wires themselves had string in them). Someone had put up a nice pinout of the microphone but that site literally just went kaput and its robot.txt file blocked internet archive, I should've made a copy of it sooner. Thankfully someone posted the manual of the radio which had a pinout of the microphone hidden on one of the pages.

Next you need (well you don't need but I HIGHLY recommend) the Easy Digi interface kit ( http://www.aracc.org/easydigi!.pdf ), they're like $10-$15 assembled on ebay. The only two lines I need from the microphone are MIC IN, and MIC GND, these are labled on the Easy Digi board. Next you need a 3.5mm mono audio jack that you can unscrew and solder wires to the "sleeve" and "tip", this goes on the "RX Audio" part of the board. It's very simple, the long part is the sleeve or GND, and the tip is the signal. Since there's a transformer you can connect the tip and sleeve to either part of the "RX audio" pins, and those go to the external speaker jack of the radio (I need the 3.5mm to 6.35mm adapter for my radio).

Next connect 2 more 3.5mm audio jacks on the end of the board (it's labled), one of these go to the speaker of your PC and the other to the microphone. I was a bit confused b/c I was getting a short between the tip and the sleeve on the audio jack, but that's because of the short from the transformer. So don't freak out about that, there's a transformer there!

I'm not using the serial connection on the connector, so you can do that if you want but it'll be a lot of wires coming out so you need good craftsman skills (mine are "meh"). You don't need the serial connector though, I can use the "VOX" feature of the radio which will do the switching between TX and RX for me. If your radio doesn't have a VOX then you need to manually switch or you need the serial control of that switching (it may still not work on your radio).

I would recommend using Windows unfortunately (I would like to use Linux too), fldigi installs very easy on it, as well as a ton of other digital radio software. I'm using fldigi, but other programs can be used of course.

Once you have fldigi installed, be sure to check the correct audio devices are connected. You need a good antenna (it's good to get an antenna switch so you can switch between a bunch), if you don't have a good antenna you won't be able to do much. Look up the PSK31 frequencies (14.07MHz as you can see in pic below is a good freq.) and look for the "mark" and "space" fork looking signal of a typical PSK31 transmission and click on it. Pretty cool reading the text being received, pretty funny that there's even backspace characters being sent, just seems weird to think about. Transmitting, there's a little button you can press (after turning on the VOX feature) and anything you type will be transmitted, but you need to turn the power down first and check your antenna w/ a SWR meter etc.