[Chris D] noticed that the excellent software defined radio (SDR) software gqrx will run on the Raspberry Pi now. So he married a Raspberry Pi 3, a touchscreen, an RTL-SDR dongle, and an upconverter to make a very nice receiver setup. You can see the receiver in action below.
The video is a little light on build details, but there is a shot of the setup with the pieces labeled, and you should be able to figure it out from there. Of course, gqrx works with lots of different SDR devices so you might have to make adjustments depending on what you use (for example, many of the supported dongles won’t need the upconverter that [Chris] uses).
Experimental Raspberry Pi support for gqrx has only been in place since October of last year, but as you can see in the video, it appears to work quite well. Using a more powerful SDR module would make it even better, but be sure to check the gqrx site for information on what hardware is working with the Pi.
We’ve seen gqrx on a lot of different platforms, and its features along with the wide range of SDR hardware supported, makes it a very useful tool, indeed. If [Chris] is looking for a neat case, we might suggest this. If you want to build SDR, but don’t want to use canned software like gqrx, we suggest GNU Radio.
To clarify what was said regarding the necessity of an upconverter, any of the RTL-SDR dongles will need the upconverter if you’re interested in listening to the low bands. Depending on the chipset, they cut out between 60 MHz and 24MHz and go no lower. There are hacks for “direct sampling” them to get lower frequencies out, but the results are hit and miss and of generally low quality (the sensitivity takes a big hit). Putting an upconverter (such as Ham-It-Up or SpyVerter) in-line makes a big difference. I recently ran across an article about someone who built their own upconverter with a 6ME8 tube (old-school, represent!): http://www.rtl-sdr.com/using-a-beam-deflection-tube-as-a-mixer-for-an-rtl-sdr-upconverter/ , so there are a number of homebrew options out there to consider as well!
This vacuum tube hack is really cool :D
I’ve been thinking of doing the same. Shame the SpyVerter doesn’t have pass-through when it’s off.
A good VHF antenna is usually a very poor HF antenna. So you really need to switch, anyhow. I like to use a mini-whip for HF.
Need to work out how to wire up a rotary encoder, with a big ol’ knob, for tuning.
Or, you could just use an Android tablet, connect the RTL-SDR stick to it, and run the app “RF Analyzer”.
Maybe not as many bells and whistles as gqrx, but a much cheaper setup, and more portable.
I use it all the time to troubleshoot rf hardware.
Yeah, there is SDR Touch as well. But this is also cool, and GQRX!
Or buy a $50 windows tablet.
Many things are possible, this is an article on one specific way and a nice way to remind you a raspi compatibility has been reached.
Hello guys!
thanks a lot for mentioning my video on your website and for all the suggestions! :)
here are some more technical details about the project just in case that anyone is interested in:
hardware:
1. RPI 3
2. 7″ official touchscreen for RPI – https://www.raspberrypi.org/blog/the-eagerly-awaited-raspberry-pi-display
3. Cheap RTL-SDR TV dongle based on RTL2832U
4. UpConverter is a custom-build based on TA7358AP – https://www.scribd.com/doc/207624956/Ta7358-Hf-to-Vhf-Upconverter
software:
1. Latest version of Raspbian OS
2. GQRX 2.6 for RPI
If I find some time my plan is to:
– Build input controller with few switches and rotary encoder for tuning
– Add front-end RF filters
– Replace crystal oscillator in RTL-SDR dongle with some TCXO
– Battery power
– Put all the parts in some nice casing
Is there a non-scribd version of that upconverter build somewhere? Scribd is basically the devil incarnate and I couldn’t find an alternate version of the PDF with a quick google.
http://chertseyradioclub.blogspot.co.uk/2016/09/gqrx-26-update-now-working-raspberry-pi.html?m=1
It is almost time to update your Raspberry Pi to protect against the Broadcom WiFi chip vulnerabilities that can exploit the Raspberry Pi in a drive by WiFi attack. Details on the Pre-release patch are available on my blog if you want to patch the Broadcom drivers now. See https://leeneubecker.com/raspberry-pi-patch-to-protect-against-broadpwn-pre-released/
I have a question. I am wanting to build a general coverage receiver for SWL. Any ideas on how I can achieve it? I am a complete NOOB when it comes to SDR.
Thank you for any help in this.