SDRs

I have recently been experimenting with software-defined radios (SDRs). I’ve got a small collection of three of them: a NooElec SDR2, a Nano Three, and an RTL-SDR.com v3. I have set up a Raspberry Pi as the SDR server.

My SDR setup as of November 4.

In the picture above, you can see the main components of the SDR setup. On the top shelf is the Raspberry PI itself, encased in a gray aluminum case. This case is actually pretty amazing; it is a heatsink for the PI, and it keeps it running extremely cool.

Hanging down is a black box with a purple Ethernet cable coming out of it. This is the power-over-Ethernet (POE) splitter. Across the room near the router is the POE injector. This feeds 48VDC and network signals across the Ethernet cable; the splitter then splits that into network and 5VDC (or 9VDC or 12VDC; it’s switchable) for use. This allows me to run one cable to the Pi instead of two.

Hanging somewhat in mid-air is the RTL-SDR.com v3 SDR. It’s connected to the Pi by a short male-to-female USB cable, and it’s connected to my external 2m/70cm J-pole vertical antenna outside. This SDR easily covers 24MHz through 1.7GHz in IQ mode; in direct sampling mode; it will receive to below 1MHz (with a couple of caveats).

For software, I’m running OpenWebRX by AndrĂ¡s Retzler (HA7ILM). It is an HTML5-based interface that runs on my Pi and talks to the SDR. It works quite well, and it’s under current development.

OpenWebRX, monitoring the lower end of 2m

So, that’s the SDR setup. Just to let you know, all that costs under $100, and it can be even cheaper if you forgo the case and the POE injector/splitter pair. I’d suggest the RTL-SDR v3 as your first SDR; it’s great, and they’re $21 on Amazon.

If you have any questions, please don’t hesitate to e-mail me.

73