Listening to radio using a software defined radio

[bkt]

For folks who are not ham radio operators but who would like to listen and understand what's being broadcast, a software defined radio may be the way to go. This requires a computer, an inexpensive USB device and an antenna. That's it. This is receive-only; you can't transmit using this SDR.

This gives a quick overview of what SDR is and how it works:


You can buy the complete kit mentioned in the video above here: RTL-SDR Kit

Or, you can purchase just the USB dongle by itself: RTL-SDR dongle only

I prefer a much longer horizontal antenna, so I purchased this: Insulator for a dipole antenna and the necessary adapter cable: SMA male to PL-259

The antenna wire itself is just 50' of copper speaker wire connected to the lead on the insulator that goes to the center pin (not the lead that goes to the outer shielding). I didn't use the other lead on the insulator.

I also made a window pass-through so I could string this between the second story of my house to a tree on the other side of the yard and still fully close the window. The antenna was about 18-20' off the ground and strung horizontally.

The $40 kit is OK and will get you started, but you may have a very hard time pulling in broadcasts (of any sort, not just commercial radio) from around the world. If you want to listen to stuff in Europe, you're going to need a better antenna. For around $100, you can put together the rig I use and that will pull in transmissions from around the world.

Why use a SDR over a shortwave receiver? Flexibility! Many shortwave receivers are AM or FM only (no SSB) and none I know of can decode digital signals of any sort. The free SDR software can do those things and it really opens up doors.

 

[dademoss]

The free SDR software can do those things and it really opens up doors.

SDR is a lot of fun to explore and experiment with.

 

[kd4ulw]

It’s been a while since I had my SDR on, I need to get more familiar with its features.

I will try out the web SDR on the Internet to see about monitoring my outgoing signal on HF. The closest thing to that was one time during a contest I looked up a station and they were running a WebCam and I was able to listen to my signal as they received it in Spain.

 

[kd4ulw]

I just brought up the WebSDR site, this receiver is in the Netherlands and apparently there’s a radio contest going on.

 

[bkt]

Just to make it a little easier: download SDR# for Windows here

GQRX for Linux and Mac

I preferred this over GQRX: CubicSDR for Linux

Flight tracking: Dump1090 for Windows and Dump1090 for Linux

This will just get you started. There's a ton of great software out there that does a lot more with decoding radio. Have fun!

 

[Magus]

Many stations also have an app that lets you listen free, much like Clyde Lewis and Alex Jones. I think Coast to coast had one.

 

[Haertig]

I have that same SDR that bkt linked. It works well for as cheap as it is.

You need software to run it (duh!) You can get a nice Linux distro that contains a lot of ham radio software here:

https://skywavelinux.com/
This LiveCD contains several software options to use with your SDR. What "LiveCD" means is that you can stick it in your CD drive and boot straight off it. No installation required. Use it, and when you're done, remove the CD and reboot. You're right back to your regular computer operating system. Warning: Running directly from a CD is slow. You will probably want to install it, run it from a virtual machine, or run the LiveCD iso off of a flashdrive rather than a CD.

This LiveCD has the software that bkt mentioned above on it (not SDR# thought, because it's a Linux LiveCD, not a Windows CD). Based on Ubuntu, so you can easily install things from their repro if you need additional stuff. I would swear that my LiveCD had Chirp on it, but I don't see that listed on their website currently. I now use a native install of Chirp rather than running if off a LiveCD image.