RTL-SDR receiver versions

An RTL-SDR is a USB stick that turns a slice of the radio spectrum into samples for the computer to demodulate. In this app it runs straight in Chrome, Edge or Opera over WebUSB, with nothing to install beyond a driver step on Windows or Linux (see getting started). The stick matters less than you might think. What counts for the app is the tuner chip: an R820T, R820T2 or R828D gets full support, the R828S in the new V4L basic support, older tuners only a basic mode.

RTL-SDR Blog V3

The V3 is the stick to buy today. It has an R820T2 tuner the app fully supports, a TCXO so frequencies are right without calibration, a 4.5 V bias-T for an LNA or active antenna, an SMA socket and a metal case. Shortwave below 24 MHz works by direct sampling, which is usable but noisier than an upconverter. Buy the kit if you have no antenna yet: its telescopic dipole covers most of VHF and UHF. The V3C is the same receiver with a USB-C socket.

RTL-SDR Blog V4L (Lite)

The V4L is RTL-SDR Blog’s newest stick, released in 2026 after the V4 ran out. It uses the Rafael R828S tuner, a version of the V4’s R828D with one RF input fewer. The maker keeps the V4’s built-in HF upconverter, PCB layout, 1 PPM TCXO, 4.5 V bias-T with its LED and the improved power supply. The input is split two ways, HF and VHF/UHF, where the V4 split it three ways, so there is less filtering against strong signals and slightly better sensitivity. There is no notch filter. The maker calls it a limited edition: the R828S is out of production too, and its stock of chips should last about a year.

In this app the V4L works at a basic level for now. The app recognises it as Blog V4L · R828S and tunes it from 24 MHz up like any supported stick, but it does not switch the V4L’s upconverter yet, so shortwave below 24 MHz is not available on it. Full support waits for reports from owners. If shortwave in this app is what you are after today, the V3 by direct sampling is the stick that does it. Other SDR programs need an updated driver for the V4L; this app has its own and needs only the usual driver step.

What happened to the V4

RTL-SDR Blog has ended the V4. Rafael no longer makes its R828D tuner, the last stock of chips is gone, and the maker says no more V4s can be built. Some resellers may still have a few. Marketplaces are full of fake V4 listings, mostly a copied V4 case with a V3-clone board inside, so buy a "V4" today only from a seller you trust. If you already own a genuine V4, the app fully supports it and switches its upconverter for shortwave on its own.

Whichever stick you pick, it works better a metre or two away from the computer. The USB extension, the OTG adapter for a phone and the ferrites are on the accessories page, and the antennas and filters have their own page.