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.

Drawing out pinout of microphone port, checking continuity

Close-up of the device (cord blocks view a bit...)

As seen connected to radio and computer

A bit of what fl-digi looks like

Connect to Wifi Networks Far Away with a Yagi Antenna and USB-Wifi Dongle

Another quick and fun mini project.  I had to get the coax connector with SMA connector and N-type connector from the Dayton Hamvention (most hamfests would work probably).  I needed a RP-SMA to SMA converter too since there's a regulation that pretty much any wifi device you buy in a store with external antenna connectors needs to use RP-SMA (I don't see the usefulness in this...).

The wifi dongle I used was a TP-Link Archer T2UH and I used a 2.4GHz yagi antenna bought online.  You can make your own yagi antenna with paper clips or pringle cans or coffee cans but...look how much cleaner this antenna is. :p

All found from a Hamfest and Fry's Electronics

Use Arduino Uno as a USB-to-Serial Adapter

( https://oscarliang.com/use-arduino-as-usb-serial-adapter-converter/ )

I needed a USB to Serial adapter when I was trying to debug why I couldn't flash an open source firmware to a router (ended up not being able to do that).  In this website, the blogger gives three methods.  I found the sketch upload (#3) one the easiest and it worked.  I was able to then read the uboot sequence from a router I was trying to upload an open source firmware to (Couldn't do it from webflash or TFTP, couldn't find out why).

Connected to a TP-Link router

Boot sequence from serial port, not sure what's happening at very start

AM Radio as a "Bug" Detector

This is a simple but fun one.  I'm using a La Crosse weather radio. Set to AM, go to quiet frequency, then you have to get the radio within at least 3 or less inches to any kind of electrical device and you hear a very loud and ugly static noise, occasionally what sounds like some kind of clear modulating tones on some devices. One of my LCD's had a weird signature that you'd be able to pick out among my others. I tested turning off my iPad and seeing if it was still on (I think it still is but you can't really tell), and I tried it on my phone charger. When you unplug the charger, for 5 seconds or so I guess a cap is still discharging and the noise continues then promptly shuts off.

The primary use case I see for something like this would be to check that your laptop/cellphone is really off and not transmitting after turning off/removing battery (so security use cases). Of course you could get unlucky if a malware has some pre-programmed random times to transmit and you miss it. Just put your device in a static bag and metal box (padded w/ foam for audio muffling) if that's a problem for you.

Got some pics of the radio internals, this is a very hacker friendly device (but quality could be a bit better).  I did spot a 1N4148 diode up around the light, as well as some transistors, and a 100K resistor (10K's are other places), that's the AM detector circuit I suspect.

What the front looks like

When you first open case

Flipping over the PCB