RTL-SDR Blog V4
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| Frequency | 500 kHz - 1.766 GHz (HF via built-in upconverter, VHF, UHF) |
| Bands | HF (via upconverter), VHF, UHF |
| Power | RECEIVE ONLY. No transmit. |
| Modes | All modes via SDR software |
| Weight | 25 g (0.9 oz) - ~25g. USB dongle with aluminum shielded case. |
| Connector | SMA-F |
| Year | 2023 |
| antenna | SMA-F |
| usb | USB 2.0 (power + data) |
| power req | USB bus powered. No external power required. |
Strong value: pocket money for 500 kHz-1.7 GHz. A built-in HF upconverter (just tune, no setup), a triplexer that isolates HF/VHF/UHF, notch filters, a 1 PPM TCXO, a bias tee, and an aluminum case. A dipole antenna is included. It has a large community and tutorial base, works with every major SDR software, and runs on a Raspberry Pi and Android.
Limited edition (the R828D is out of production; buy now or get the V3). An 8-bit ADC (the Airspy's 12-bit has better dynamic range). 2.4 MHz stable bandwidth (the Airspy Mini does 6 MHz). Receive only. No HF filtering (urban strong signals can still overload). The included dipole is adequate for testing only. The V3 remains available as a fallback.
A standout entry-level SDR. The RTL-SDR Blog V4 puts 500 kHz to 1.7 GHz into a pocket-money USB dongle with a built-in HF upconverter, triplexer, TCXO, and bias tee. It is a common first SDR. The R828D chip is out of production, making the V4 a limited edition; grab one while they last, or get the V3, which continues in production.
The RTL-SDR Blog V4 is the definitive budget software-defined radio: a tiny USB dongle that, paired with free software on a computer, turns into a wideband receiver covering roughly 500 kHz up to 1.766 GHz. It is built around the Realtek RTL2832U chip (which is the demodulator, not the tuner) paired with an R828D tuner. Crucially, it is receive-only; like all RTL-SDR dongles it cannot transmit.
What separates the V4 from earlier RTL-SDR dongles and cheaper clones is its HF handling. Rather than the awkward direct-sampling mode of the V3, the V4 has a proper built-in upconverter so the shortwave bands come in cleanly with full gain control. It also adds a triplexer to separate the HF, VHF, and UHF inputs, switchable notch filters to knock down strong broadcast stations, a 1 ppm temperature-compensated oscillator, and a software-switchable bias tee for powering a remote preamp. The catch is the 8-bit sampling shared by all RTL dongles, which limits dynamic range compared with premium receivers.
An important note for 2026: the V4 reached end-of-line when its R828D tuner chip went out of production, so new stock is drying up and a 'V4 Lite' successor is in the works. While they last, it remains the entry point to the hobby, a step up from the cheaper NooElec NESDR SMArt, and a world away in price from premium receivers like the Airspy HF+ Discovery.