SDR and RTL-SDR review

In the past week, I finally put my hands on the RTL-SDR RTL2832U dongle. This little device is amazing in it’s capabilities. These little devices do not function to much different than a general all purpose receiver, but everything about them is what makes them so great. A general all-purpose receiver from Icom would cost in the ball park of five-hundred US dollars. SDR, they can cost from a few hundred to a significant fraction of that.

There are many out there, but I decided to choose RTL-SDR’s RTL2832U. This device can be purchased off of amazon for $25, and it comes as a kit. It comes with a dipole-style antenna with two mounting systems. One that is a tripod with bendable legs and the other is a suction cup. The antenna is efficient enough to get the feet wet. To focus on a certain set of frequencies, it would always be best to purchase or homebrew and antenna that would be full, half, or quarter wave-length.

One of the greatest aspect of the RTL-SDR dongles is that most of the software out there for SDRs are compatible with their hardware. Best of all, everything needed software-wise has a great free and opened sourced project around it. Currently I am running GNU Radio and GQRX (GQRX requires GNU Radio) and I am capable of doing everything paid software can do. Best of all, it is Richard Stallman approved (according to VRMS, Virtual Richard M Stallman). From my android, I download SDRTouch and I can plug into my phone and use this device mobile from my phone. For $10 extra, I can unlock all of SDRTouch’s.

This device plugs into a computer or can be plugged into a phone or tablet via USB. For a phone or tablet, an adapter will most likely be needed to go from USB to MicroUSB or USB C. The dongle itself is smaller than a credit card and about a quarter to half inch thick. On the other end is a small coaxial port.

After and launching the software, a waterfall display in software such as GQRX or SDRTouch will appear and your read to scan around the frequencies that this dongle receives. You can see the shape of signals and where they come in at without having to manually scan through each individual frequency.

The RTL3282U out of the box and plugging in receives frequencies from 24 MHz through almost 1.8 GHz. By modifying the software to using direct sampling, frequencies between 500 kHz through 24 MHz becomes accessible. Making this a great device for amateurs who wish to listen into the HF portions of the Ham Bands. Note than when in direct sampling mode, only 500 kHz through 30 MHz will be accessible. To listen in on 24 MHz through 1.8 GHz, you will need to remove the device from direct sampling mode.

For getting one’s feet wet in radio, I would recommend the RTL-SDR RTL3282U to everyone. For everything this little device can do for the price, it is an invaluable tool for tinkering and learning. 


Categories: Programming

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