RTL-SDR Blog V4 Review (Discontinued): Built-In HF, TCXO, What to Buy Now
This review was written while the RTL-SDR Blog V4 was the default answer to "what SDR should I buy?" It covered 500 kHz to 1.766 GHz and worked with every major SDR program. It is kept here as a record of what changed from the V3 and how the built-in HF performed — useful if you own a V4 or are looking at a used one. If you are buying new, skip to what to buy now.
What's New in the V4
The V4 moved RTL-SDR Blog's design from the R860 tuner used in the V3 to the Rafael R828D. That choice is also why the V4 ended: RTL-SDR Blog says its R828D stockpile is exhausted and no further V4 production runs are possible.
The meaningful changes:
- Built-in HF reception via an internal triplexer, no upconverter required
- Improved filtering that rejects FM broadcast band overload and common out-of-band interference
- 1 PPM TCXO for frequency stability across temperature
- Aluminum enclosure with a thermal pad to the PCB for better heat dissipation
- SMA antenna connector (not MCX)
- USB passthrough bias tee for powering LNAs and active antennas (software-controlled)
None of these are paradigm shifts. They're the accumulation of five years of feedback on what RTL-SDR dongles needed. The built-in HF was the headline feature and the reason we recommended the V4 over the older V3 while it was available. With the V4 discontinued, the V3 is the RTL-SDR Blog model you can still buy new.
V4 vs V3: The Comparison That Matters
| Spec | RTL-SDR V4 | RTL-SDR V3 |
|---|---|---|
| Tuner chip | R828D | R860 |
| Frequency range | 500 kHz – 1.766 GHz | 500 kHz – 1.7 GHz |
| HF reception | Native (triplexer) | Direct sampling mode (built in) |
| TCXO | 1 PPM | 1 PPM |
| Filtering | Improved multi-stage | Basic |
| Bias tee | Yes (software toggle) | Yes (software toggle) |
| Enclosure | Aluminum + thermal pad | Aluminum |
| Connector | SMA female | SMA female |
| Availability | Discontinued (May 2026) | In production — $37.95 |
While the V4 was on sale, its built-in HF saved HF listeners the cost of a separate upconverter. Now that it is discontinued, the choice is simpler: for VHF/UHF and 700/800 MHz P25 with SDRTrunk, the V3 works. For HF, the V3's direct-sampling mode performs worse than the V4 did, so pair a V3 with an HF upconverter or look at a dedicated HF receiver.
Real-World Reception
HF (500 kHz – 28 MHz)
With a long-wire HF antenna, the V4 can receive international shortwave, amateur SSB/CW and WSPR beacons when the band is open. Its 8-bit ADC means strong stations can desensitize nearby weak ones on crowded HF bands. For serious DX work, see our Airspy vs RTL-SDR comparison.
VHF/UHF (28 MHz – 1.766 GHz)
This is where RTL-SDRs have always shone, and the V4 is the best one yet. Public safety in the 450–470 MHz band, 700/800 MHz trunked systems, 1090 MHz ADS-B, 137 MHz weather satellites — all work well. The improved filtering is most obvious if you live near an FM broadcast tower: the V3 will get overloaded and bleed images into the air band, while the V4 cleans most of it up without an external notch filter.
P25 Digital
The common SDRTrunk setup for a trunked P25 system uses two dongles, one parked on the control channel and one following voice traffic; our SDRTrunk setup guide walks through it. A single dongle is usually enough for a conventional (non-trunked) P25 channel.
Software Compatibility
The V4 works with every major SDR program as long as you're on updated drivers:
- SDR# (SDRSharp): Works natively with the RTL-SDR V4 driver branch
- SDR++: Full support, cross-platform
- GQRX: Works on Linux/macOS with updated librtlsdr
- SDRTrunk: Primary SDR for P25/DMR trunking at this price point
- SDRangel: Full support
- HDSDR: Works via ExtIO
- dump1090: ADS-B aircraft tracking
- DSD+ Fastlane: For digital voice decoding
Older guides still circulate that use RTL2832U drivers predating the V4. If you tune below 28 MHz and get silence, you're on the wrong driver — grab the RTL-SDR Blog V4 branch and the HF band will come alive. Our SDR software comparison covers which program to pick for which task.
Who the V4 Suited (and What to Buy Now)
The lists below are from when the V4 was on sale. For every "good fit" case except native HF, the V3 is now the RTL-SDR Blog dongle to buy.
Good fit
- First-time SDR buyers
- Upgraders from older RTL2832U dongles
- HF listeners without an upconverter
- P25 trunking builders (two dongles; the V3 works here too)
- ADS-B, weather sat, and scanner-style monitoring
Skip it for
- Serious HF DX — get an Airspy HF+ Discovery
- Wide-bandwidth analysis (>2.4 MHz) — see SDRplay RSPdx
- Transmit capability (it's receive-only)
- Decrypting encrypted police — no receiver can do that
What to Buy Now
RTL-SDR Blog V3
The V4 can no longer be bought new. RTL-SDR Blog says the V3 will remain in stable production, and it covers the same VHF/UHF and 700/800 MHz territory that most scanner listeners use, including P25 with SDRTrunk. Its HF reception comes from direct sampling, which performs worse than the V4's built-in upconverter did. The V4L "lite" successor is sold through RTL-SDR Blog's own store, eBay and AliExpress; Amazon stock is expected but not yet listed.
Check Price on Amazon →Check AvailabilityRTL-SDR Blog Multipurpose Dipole Antenna Kit
Add an antenna if you are starting from scratch: a wideband indoor dipole kit designed for RTL-SDR dongles.
Check Price on Amazon →Check AvailabilityFrequently Asked Questions
Is the RTL-SDR Blog V4 worth it over the V3?
The question is now moot for new buyers: RTL-SDR Blog announced on May 14, 2026 that the V4 is end-of-line because its R828D tuner stockpile is exhausted, and that the V3 will remain in stable production. While it was on sale, the V4's advantages were native HF reception through a built-in upconverter (no external upconverter needed) and improved filtering against FM broadcast overload. If you already own a V4, keep using it. If you are buying today, get the V3: it handles VHF/UHF and 700/800 MHz P25 with SDRTrunk, and receives HF only through its direct-sampling mode, which performs worse than the V4's HF path.
What is the frequency range of the RTL-SDR V4?
The V4 covers 500 kHz to 1.766 GHz continuously, with native HF reception below 28.8 MHz and direct VHF/UHF reception above it. The built-in triplexer handles the handoff automatically, so you don't need an upconverter or mode switch.
Does the V4 need drivers?
The V4 works with existing rtl-sdr drivers, but you need a recent build. Use the RTL-SDR Blog V4 driver branch on Windows or upgrade libusb and librtlsdr on Linux/macOS. Older drivers written for R820T2 tuners won't recognize the R828D and will fail to tune below 28 MHz.
Can I decode P25 with an RTL-SDR V4?
Yes, using DSD+ or SDRTrunk — and so can the V3, which is what to buy now that the V4 is discontinued. For P25 Phase I conventional channels, one V4 is enough. For P25 Phase II trunked systems, you should run two V4s — one on the control channel and one on voice — to avoid missing call transitions. See our SDRTrunk setup guide.
What antenna comes with the V4 bundle?
The RTL-SDR Blog V4 dipole kit includes telescopic antenna elements (dipole and monopole configurations), suction cup and clamp base mounts, three meters of RG174 coax, and SMA adapters. It covers roughly 25 MHz to 1.7 GHz with element adjustment and is a genuinely useful starter antenna.
Is the TCXO on the V4 accurate enough for digital modes?
The V4's 1 PPM TCXO holds frequency within roughly ±1.5 kHz at 1.5 GHz, which is stable enough for P25, DMR, NXDN, and most ham digital modes. For weak-signal HF work (WSPR, FT8 at the edge), a GPS-disciplined oscillator would be better, but the V4 is far tighter than the ~30 PPM crystals used in generic RTL2832U dongles.
Can the V4 decode encrypted police radio?
No. No receiver — SDR, scanner, or otherwise — can decrypt AES-256 encrypted police traffic. If your local agency has encrypted, the V4 won't change that. It will, however, still pick up unencrypted fire, EMS, aviation, amateur, railroad, and federal conventional traffic in your area.
Is RTL-SDR V4 better than a dedicated scanner for beginners?
For dedicated police scanning, a BCD436HP or SDS100 is easier to set up and more reliable for trunked P25. The RTL-SDR V4 requires a laptop running SDRTrunk, more configuration, and has no LCD display. However, an RTL-SDR dongle costs a fraction of the BCD436HP's $450+ and covers a far wider range of uses (aircraft ADS-B, weather, amateur, and — on the V4 — HF shortwave). The V4 is discontinued, so if you want broad experimentation and don't mind setup complexity, buy the RTL-SDR Blog V3 instead; choose a dedicated scanner if you want a plug-and-play police monitoring experience.
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