The world of Software Defined Radio (SDR) has been revolutionized by affordable dongles that turn any computer into a sophisticated radio receiver. The RTL-SDR Blog V4, featuring the R828D RTL2832U chipset, represents the latest evolution in this remarkable journey. Priced at just $29.95 for the dongle alone, this fourth-generation device promises to address many of the limitations that plagued its predecessors while maintaining the accessibility that made RTL-SDR dongles a phenomenon.
But is the V4 truly a significant upgrade, or just another incremental improvement? After diving deep into specifications, user reviews, and comparative analyses, the answer is refreshingly clear: this is the most substantial upgrade the RTL-SDR Blog series has seen to date.
- Includes 1x RTL-SDR Blog V4 R828D RTL2832U 1PPM TCXO HF Bias Tee SMA Dongle and 1x Multipurpose Dipole Antenna Kit
- Several improvements over other brands including use of the R828D tuner, built in HF upconverter, improved component tolerances, a 1 PPM temperature compensated oscillator (TCXO), SMA F connector, aluminum shielded case with thermal pad for passive cooling, improved filtering, activatable bias tee circuit and a much improved antenna set.
- Can tune from 500 kHz to 1.7 GHz and has up to 3.2 MHz of instantaneous bandwidth (2.4 MHz stable). Please note RTL-SDR dongles are RX only.
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What Makes the V4 Special: Key Specifications
Core Hardware
Chipset: R828D tuner with RTL2832U ADC
Frequency Range: 500 kHz to 1.766 GHz
Instantaneous Bandwidth: Up to 3.2 MHz (2.4 MHz stable)
Oscillator: 1 PPM Temperature Compensated Crystal Oscillator (TCXO)
Connector: SMA F connector
Power: Software-activatable 4.5V bias tee (up to 180mA)
Interface: Available in both USB-A and USB-C variants
The Game-Changing HF Upconverter
Perhaps the most significant advancement in the V4 is its built-in HF upconverter. Previous RTL-SDR dongles, including the popular V3, relied on direct sampling for HF reception, which created a host of problems including Nyquist folding around 14.4 MHz. This meant that signals would appear as aliases at incorrect frequencies, making accurate HF monitoring challenging.
The V4’s SA612 double-balanced mixer circuit upconverts HF frequencies by 28.8 MHz, eliminating these artifacts entirely. As one user noted in testing, “Unlike V3, the sampling mode remains unchanged at Quadrature Sampling. The receiver automatically recognizes when it needs to enable the upconverter. For the user, this means that they can tune continuously from zero to 1000 MHz.”
Design Excellence: Engineering That You Can Feel
Improved Filtering Architecture
The V4 implements a sophisticated three-band filtering system that leverages the R828D tuner’s three inputs. The SMA input is split into three bands: HF (0-30 MHz), VHF (30 MHz to 300 MHz) and UHF (300 MHz+), providing isolation between the three bands and reducing out-of-band interference from strong broadcast stations.
Additionally, the device includes notch filters for common interference sources like broadcast AM, FM, and DAB bands. While these filters only provide a few dB of attenuation, they can make a meaningful difference in challenging RF environments.
Thermal Management and Build Quality
The V4 retains the sleek aluminum enclosure introduced with the V3, but with improvements. It uses better components, a redesigned lower noise PCB, cooling improvements, additional filtering, extra ESD protection and an SMA F connector. The case doubles as both an RF shield and a heatsink, with a thermal pad transferring heat away from the PCB.
A thoughtful addition is the bias tee LED indicator, visible through a small hole next to the SMA connector, allowing users to quickly confirm when the bias tee is active.
Real-World Performance: How It Measures Up
HF Performance Breakthrough
Multiple independent reviews have highlighted the V4’s superior HF performance. Chris (NNN0BOC), in his comprehensive review, noted that “The V4 seems to atone for some of the sins of the V3, especially on HF with specific regard to Nyquist aliasing, have no fear tuning above 14.4MHz dear friends, this thing won’t be making aliases unless you are overloading it.”
In practical terms, this means:
Clean reception of HF signals without phantom artifacts
No need to switch between sampling modes
Consistent performance across the entire frequency range
Better sensitivity on HF compared to direct sampling methods
VHF/UHF Improvements
The filtering improvements extend beyond HF. Comparative testing found “an improvement in the 145 MHz region where the V3 has a pumping noise floor from out of band interference, whereas the V4 does not thanks to its additional filtering.”
The Trade-offs: What You Give Up
However, the V4 isn’t without compromises. Due to the increased filtering there can be an average of 2-3 dB less sensitivity on some bands. This trade-off between interference rejection and raw sensitivity is generally favorable for most users, as cleaner signals often matter more than marginally stronger but noisier reception.
Software Compatibility and Setup
Driver Requirements
The V4 requires updated drivers to function properly. Because of required changes made to the circuitry, new drivers are required for the RTL-SDR Blog V4. These drivers are backwards compatible with the RTL-SDR Blog V3 and older / other branded / generic RTL-SDR units as well.
Users who don’t update their drivers will experience problems ranging from no signals to frequency errors or corrupted reception.
Bias Tee Control
The software-controlled bias tee is elegantly implemented. In most software there is an option to enable “Offset Tuning”. This option is irrelevant for R820T/R860/R828D based dongles. Instead we have repurposed it as a switch for our bias tee. This creative reuse of existing UI elements means the bias tee works seamlessly with most popular SDR software packages.
User Experience: What Owners Are Saying
Overwhelmingly Positive Reception
User reviews have been remarkably consistent in praising the V4’s improvements. One Amazon reviewer noted: “I get the impression that the V4 dongle is more sensitive than the V3. There is a long list of other improvements, particularly filters and isolation to prevent interference from strong local signals.”
Comparison with Higher-End SDRs
Particularly impressive are comparisons with much more expensive equipment. One user who had struggled with an SDRplay RSPdx wrote: “I ordered the RTL-SDR V4 the moment I first saw it and I am impressed. It works (unlike the SDR Play, which isn’t even a good paperweight), it’s several dB quieter than the HamItUp and there is no offset to deal with.”
Competitive Landscape: How Does It Stack Up?
Versus RTL-SDR V3
The improvements over the V3 are substantial:
HF Reception: Built-in upconverter eliminates Nyquist folding
Filtering: Multiple stages reduce interference
Ease of Use: No need to switch sampling modes
Build Quality: Better components and thermal management
Versus Mid-Range SDRs (Airspy, SDRplay)
While the V4 can’t match the dynamic range of 12-bit and 14-bit ADC designs found in devices like the Airspy or SDRplay RSP series, it offers remarkable performance for the price point. Direct comparison testing between the RTL-SDR V4 and Airspy HF+ Discovery showed that “The RTL-SDR v4 is a great budget SDR receiver!”
The key advantages of higher-end SDRs include:
Greater dynamic range (12-16 bits vs 8 bits)
Wider instantaneous bandwidth
Better sensitivity in challenging conditions
However, the V4’s price point makes it accessible to a much broader audience, and for many applications, the performance difference isn’t significant enough to justify the 5-10x price premium.
Value Proposition
At under $30, the V4 represents extraordinary value. “At this time I can’t think of a better value for the money when shopping for an SDR to use with a pc or phone in the sub – $50 price range.”
Applications: Where the V4 Excels
Ideal Use Cases
HF Monitoring: Shortwave broadcast, amateur radio, maritime communications
Aviation Listening: Air traffic control, ACARS, ADS-B tracking
Scanner Replacement: Public safety, emergency services
Satellite Reception: Weather satellites (NOAA APT, Meteor M2)
Radio Astronomy: Hydrogen line observations
General Spectrum Exploration: Learning and experimentation
Professional Applications
SIGINT Training: Educational environments
Interference Hunting: RF troubleshooting
Spectrum Monitoring: Basic surveillance applications
Research: Academic and hobbyist projects
Limitations and Considerations
What It Can’t Do
Transmit: The V4 is receive-only
Extreme Weak Signal Work: Higher-end SDRs with better dynamic range are preferable
Wide-bandwidth Analysis: Limited to 3.2 MHz instantaneous bandwidth
Professional Applications: Lacks calibrated measurements and professional software support
Limited Production Run
The V4 represents a limited edition design. The R828D chip stock is limited, and it is no longer in production, the V4 design is also a limited design which we expect to be able to sell for about a year. However, the manufacturer has found additional stock, extending production potentially through the end of 2025.
Purchase Options and Pricing
Available Configurations
Dongle Only: $29.95
With Antenna Kit: $39.95 (includes dipole antenna set)
USB-C Variant: Same pricing as USB-A version
What’s Included
The antenna kit version includes:
Dipole antenna base with 60cm RG174 cable
Two telescopic antennas (23cm to 1m)
Two short telescopic antennas (5cm to 13cm)
3-meter RG174 extension cable
Flexible tripod mount
Suction cup mount
Final Verdict: Should You Buy It?
Who Should Buy the V4
RTL-SDR V3 Users: The HF improvements alone justify the upgrade
Newcomers to SDR: Excellent entry point with room to grow
Budget-Conscious Enthusiasts: Best performance per dollar in its class
Educational Users: Ideal for learning RF principles
Who Might Want Something Else
Professional Users: Consider Airspy HF+ Discovery or SDRplay RSP series
Weak Signal Specialists: Higher dynamic range devices offer advantages
Transmit Needs: Look at HackRF One or similar transceivers
The Bottom Line
The RTL-SDR Blog V4 R828D RTL2832U represents a significant evolution in affordable SDR technology. By addressing the fundamental limitations of previous designs—particularly the problematic HF reception—while maintaining the accessibility that made RTL-SDR dongles popular, it sets a new standard for budget SDR devices.
Testing confirms that “the RTL-SDR Blog V4 is overload-resistant” and provides “crystal-clear reception” across its frequency range. For $30, you’re getting technology that would have cost hundreds of dollars just a decade ago.
Whether you’re a seasoned radio enthusiast looking for a portable solution, an educator introducing students to RF concepts, or a curious newcomer wanting to explore the electromagnetic spectrum, the V4 offers an compelling combination of capability, quality, and value that’s hard to beat.
In an era where many consumer electronics sacrifice quality for cost reduction, the RTL-SDR Blog V4 stands as a refreshing example of genuine engineering improvement at an accessible price point. It’s not just an upgrade—it’s a transformation of what’s possible in budget SDR technology.
The RTL-SDR Blog V4 R828D RTL2832U dongle is available directly from RTL-SDR.com and Amazon, with worldwide shipping available. Given the limited production run, interested buyers should consider purchasing sooner rather than later.
