Software Defined Radio

The U.S. Army has been looking at this technology for quite some time.

Link is circa 2014:

https://www.army.mil/article/136164/software_defined_radios_allow_soldiers_to_adapt_to_cyber_threats

The Black Hats were playing with these in the sandbox in 2012:

https://www.aerodefensetech.com/component/content/article/adt/insiders/defense/stories/13171

Lots of work to be done:

https://en.wikipedia.org/wiki/Joint_Tactical_Radio_System

As a former SigO, I have a mild interest in the technology.

I bought a SDR dongle with a small antenna for 16 bucks on ebay, about 10 years ago. This was when SDR was just beginning for hobbyist The SDR programs didn't have all the plug-ins and features they have now. But it had the waterfalls and basic features. It only went down to 25MHz, so no HF ham or AM broadcast.(or VLF for that matter) But still very impressive. I sent one to each of my four sons. And finally, was able to get them interested in radio, after me trying all their lives. I guess seeing is believing. When I first saw it, I called it seeing or visual radio.

If you like building radio circuits,(for a range of VLF thru HF) and want a much simpler strategy for SDR front ends,(the dongle part) I suggest the Tayloe mixer. The IQ baseband output can be fed directly into a sound card. And of course the Tayloe mixer can be used to modulate an emission too. There are non-license experimental frequencies to transmit on. There is some regulation around airports and such. There are all kinds of user groups for VLF and such.

There has also been some interesting results using short configuration piezo electric antenna materials for low frequency reception and emission. Finally short antennas for long wavelengths. Right through mountains and deep in mines.

It is cool and interesting although hardly surprising, since a computer has all the basic components needed by a radio or a TV..

I own a decent SW radio (Grundig Satellit 750), and recently bought an Ocean Digital WR-230s internet radio (WiFi or direct ethernet connection). The latter gets 1000's of stations. You can select by global geographic region, then break that down to stations within a country. Alternatively, you can select by genre, then break that down to specifics - jazz from the 40's for example. Or, if Tuvan throat singing is your thing, you will not just find one station, but dozens to satisfy your throat singing listening needs. Too much choice!

Has anyone seen this?

https://youtu.be/uvUq81jIzPg

I thought it was a very good use of SDR.

Cool link. Thanks!

In the video it looks like they are using GNU radio. With it you can virtually build just about any kind of radio using blocks that you link together to control your SDR hardware.

Years ago I used GNU radio (Installed to boot from a thumb drive) with a hackrf one and was able to pick up and record the remote signal to unlock my car doors while my car was out of radio range. I then replayed the signal and my car unlocked. There are some great videos that step you through using GNU radio, which will work with your cheap dongles as a receiver.

With SDR# and others there are also a great many decoder software's addons that were originally developed to take in audio from a scanner and decode it but work great with SDR. One example is DSD (digital sound decoder) which will allow you to listen to digital encoded (but not encrypted) audio. Also trunking software that will allow your SDR to follow a trunked system as many police and fire are both encoded and trunked today.

Here's an interesting use of SDR -- receive data from your car's TPMS (tire pressure monitoring system.)

https://hackaday.com/2022/04/09/sdr-listens-in-to-your-tires/