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3. Comparison Between popular SDRs
Written by Dilusha Samarasekara – Associate Member, RSSL
The world of amateur radio has experienced a transformative revolution with the advent of Software-Defined Radio. By replacing traditional hardware components with powerful software algorithms, SDR devices offer a wide range of benefits, including increased flexibility, enhanced functionality, and improved performance.
With a growing number of SDR devices flooding the market, it becomes essential for amateur radio operators to stay informed about the latest offerings and make informed choices based on their specific needs. This article aims to provide a comprehensive comparison of some of the most popular SDR devices available, empowering amateur radio enthusiasts with the knowledge necessary to select the ideal device for their individual requirements.
Throughout this article, we will delve into the key features, technical specifications, and performance metrics of various SDR devices, enabling readers to evaluate and contrast their functionalities. Whether you are an aspiring amateur radio operator looking to venture into the world of SDR, or an experienced enthusiast seeking an upgrade, this comprehensive comparison will serve as a valuable resource in making an informed decision.
We will explore a wide range of SDR devices, ranging from budget-friendly options to high-end models, considering factors such as frequency range, sample rate, dynamic range, sensitivity, and software compatibility. Additionally, we will examine the user interfaces, software ecosystems, and community support surrounding each device, as these aspects greatly influence the overall user experience and ease of integration into existing radio setups.
Model |
Frequency Range |
Bandwidth |
ADC Resolution |
Sample Rate |
Transmit Capability |
RX Channels |
TX Channels |
Bias Tee |
RF Input |
| Generic RTL-SDR Dongles | 25 MHz – 1.7 GHz | 2.4 MHz | 8 bits | 3.2 MSPS | No | 1 | 0 | Yes | MCX |
| RTL-SDR Dongle v3 | 24 MHz – 1.7 GHz | 3.2 MHz | 8 bits | 3.2 MSPS | No | 1 | 0 | Yes | SMA |
| Nooelec NESDR SMArt v5 | 100 kHz – 1.7 GHz | 3.2 MHz | 8 bits | 3.2 MSPS | No | 1 | 0 | No | SMA |
| Nooelec NESDR SMArTee v5 | 100 kHz – 1.7 GHz | 3.2 MHz | 8 bits | 3.2 MSPS | No | 1 | 0 | Yes | SMA |
| Nooelec NESDR SMArt XTR | 300 Hz – 2.3 GHz | 3.2 MHz | 8 bits | 3.2 MSPS | No | 1 | 0 | No | SMA |
| Airspy Mini | 24 MHz – 1.8 GHz | 6 MHz | 12 bits | 6 MSPS | No | 1 | 0 | Yes | SMA |
| Airspy HF+ Discovery | 0.5 kHz – 31 MHz | 660 kHz | 16 bits | 660 kHz | No | 1 | 0 | Yes | SMA |
| Airspy R2 | 24 MHz – 1.8 GHz | 10 MHz | 12 bits | 10 MSPS | No | 1 | 0 | Yes | SMA |
| SDRPlay RSP1A | 1 kHz – 2 GHz | 10 MHz | 14-bit | 10 MSPS | No | 1 | 0 | Yes | SMA |
| SDRPlay RSPduo | 1 kHz – 2 GHz | 10 MHz | 14 bits | 10 MSPS | No | 2 | 0 | Yes | SMA |
| SDRPlay RSPdx | 1 kHz – 2 GHz | 10 MHz | 14 bits | 10 MSPS | No | 1 | 0 | Yes | SMA & BNC |
| HackRF | 1 MHz – 6 GHz | 20 MHz | 8 bits | 20 MSPS | Yes (Half-Duplex) | 1 | 1 | Yes | SMA |
| ADALM-Pluto | 70 MHz – 6 GHz | 56 MHz | 12 bits | 61.44 MSPS | Yes (Full Duplex) | 1 | 1 | No | SMA |
| LimeSDR Mini v2 | 10 MHz – 3.5 GHz | 40 MHz | 12 bits | 30.72 MSPS | Yes (Full Duplex) | 1 | 1 | No | SMA |
| BladeRF x40 | 300 MHz – 3.8 GHz | 40 MHz | 12 bits | 40 MSPS | Yes (Full Duplex) | 2 | 2 | No | SMA |
| LimeSDR | 100 kHz – 3.8 GHz | 61.44 MHz | 12 bits | 61.44 MSPS | Yes (Full Duplex) | 6 | 4 | No | U.FL |
| Ettus B210 | 70 MHz – 6 GHz | 61.44 MHz | 12 bits | 61.44 MSPS | Yes (Full Duplex) | 2 | 2 | No | SMA |
Note:- A bias tee, also known as “Phantom Power” is a mechanism that is used to send DC voltage up along the transmission line. Devices like RTL-SDR V3 Dongles have this function already built-in, when enabled by the software switch it will send 4.5v of DC power into the center conductor of a coaxial cable which can be used to power active components like low noise amplifiers, RF splitter/combiners, RF switches or even active antennas like magnetic loops without needing a separate power supply. There are external bias tee boards that do the same thing but also support higher voltages and higher current and they can be used with any receiver or transmitter. They especially come in handy for applications that require more power. However, it is important to note that bias tees can introduce some level of signal loss or distortion, particularly at higher frequencies. Therefore, it is important to choose a high-quality bias tee that is designed for the specific frequency range and power level of the application.
A word about Generic SDR Dongles
These are originally meant to use as USB TV Tuners but can be used as SDRs by installing the correct driver. They are usually very cheap and come with plastic cases, So no RFI shielding whatsoever, they are easily overwhelmed by outside noise and do not have a proper TCXO (Temperature compensated crystal oscillator). Because of that if used for longer periods, actual frequencies may drift back and forth due to increasing temperature. They are good for casual VHF/UHF listening but not worth investing in for serious use in my opinion.
RTL-SDR Dongle v3
This is arguably the most popular SDR among amateurs and usually everyone’s first SDR when they first venture into the word f SDR. They are built on the same “RTL2832U” chipset as the generic models but offer better RFI shielding with aluminum enclosures and have a 0.5ppm TCXO and passive cooling, so suitable for longer operation times. Since they have software switchable 4.5v bias tee function, powering external components such as amplifiers is possible without needing additional wires. Moreover, the supported frequency range can be extended down to the HF band by switching to direct sampling mode and listening to HF signals with a suitable antenna.
Nooelec SDR Family
Nooelec is a reputable US-based company that sells many RF components, their “NESDR SMArt” devices are essentially the same as RTL-SDR dongles based on the same “RTL2832U” chipset and offer the same specifications but they have improved the overall build quality so sensitivity and dynamic range is slightly improved. Their “NESDR SMArTee” devices use a different chipset called “E4000” which offers better sensitivity than the “RTL2832U” chipset in <500MHz and >1500MHz regions and extend the supported frequency range upto 2350MHz. Both of these devices have a smaller form factor compared to other RTL-SDR-Type dongles so they can be stacked closer to each other in adjacent USB ports or a USB hub. They are Ideal for applications that require multiple SDRs such as monitoring Trunk-Radio systems like P25, TETRA, and DMR.
Airspy Family
Airspy is a well-known brand in the world of software-defined radios for their hardware devices as well as for the SDRSharp software which is the most popular SDR application among SDR hobbyists.
Airspy Mini
The Airspy Mini is the smallest and most affordable SDR in the Airspy family. It has a frequency range of 24 MHz to 1800 MHz, 12-bit ADC, and 6 MHz of instantaneous bandwidth. The Airspy Mini is a great choice for beginners who want to experiment with SDR technology and step up from the RTL-SDR-type models without breaking the bank. It is also a good choice for portable applications due to its small size.
Airspy R2
The Airspy R2 is the next step up from the Airspy Mini. It has a higher dynamic range than the Airspy Mini, which means it can handle stronger signals without distortion. It has 10Mhz of instantaneous bandwidth so it’s extremely useful for getting a panoramic view of a certain frequency range. It has additional features such as programmable IO pins, and external reference clock input for advanced users. The Airspy R2 is a good choice for beginners and advanced users alike because it is a perfect middle ground for lower-end SDRs and higher-end SDRs. In my own experience, it is my go-to device for discovering new signals and getting a general idea about a certain signal before I resort to more specific devices or methods. Also, SDRSharp and the huge collection of its plug-ins are originally built with airspy devices in mind so software support is phenomenal for airspy devices.
Airspy HF+ Discovery
The Airspy HF+ Discovery is the latest addition to the Airspy family. It has a frequency range of 9 kHz to 31 MHz with 16-bit ADC and it was specially designed for HF reception. The Airspy HF+ Discovery has a significantly higher dynamic range than other HF-capable SDRs. The Airspy HF+ Discovery also has a very low noise floor, making it a great choice for weak signal reception.
SDRPlay Family
SDRplay is a UK-based company that offers a range of software-defined radios for hobbyists, enthusiasts, and professionals. The SDRplay family includes several models, each with unique features and capabilities. Alongside they have built the “SDRuno ” software with their own set of additional plug-ins to support their devices. While SDRPlay devices can be used with most of the popular SDR client softwares such as SDRSharp or SDR++, it’s recommended to use SDRUno to take full advantage of all the software capabilities that they have to offer.
RSP1A
The RSP1A is the entry-level SDR receiver from SDRplay. It is a compact and affordable device that is designed for beginners and hobbyists. The RSP1A has a frequency range of 1 kHz to 2 GHz and a 14-bit ADC. It also has a 10 MHz bandwidth and a maximum sample rate of 10 MSPS. HF is capable out of the box and has software-selectable bandpass filters for relevant bands to improve reception. It comes in a plastic enclosure so can be susceptible to strong external noise but overall a good HF/VHF/UHF all-band SDR with a higher dynamic range.
RSPduo
The RSPduo is a dual-tuner SDR receiver that is designed for advanced users. It has two independent tuners, which allow users to monitor two different frequencies simultaneously. It has all the basic features RSP1A has but also features additional RF filters and external clock input for advanced operations. It comes in a robust metal enclosure so external noise rejection and build quality are better.
RSPdx
The RSPdx is the latest SDR receiver from SDRplay. It has three antenna ports, two of which are SMA connectors and can operate across the full 1 kHz to 2 GHz range, and the third is a BNC connector that operates up to 200 MHz.More additional filters were added for lower HF bands and dynamic range, selectivity, sensitivity, and accuracy are greatly improved compared to before mentioned SDRPlay devices. It has become popular among hobbyists as a scanner because having three different antenna ports allows users to attach specific antennas for each band and quickly scan through each band to discover signals.
HackRF
HackRF is a powerful and versatile software-defined radio that has gained popularity among radio professionals, security researchers, and hobbyists alike. It is the cheapest SDR available with the transmit capability on the market. It features a wide frequency range, which covers from 1 MHz to 6 GHz, 20 MHz of instantaneous bandwidth, and 20MSPS of sample rate, also has built-in low noise amplifiers for receiving as well as transmitting. It is designed to capture, process, and transmit radio signals across a wide frequency range and is based on an open-source hardware design by “Great Scott Gadgets”. It is compatible with various advanced software applications such as GNU Radio and offers functionalities like various signal processing and analysis, demodulating, signal generation, and spectrum analysis. It’s a great tool to have for advanced operations that demand wider bandwidth and higher sample rates such as Ultra HIgh-Quality XHRPT satellite image reception from geostationary weather satellites.
The HackRF can also be used with the PortaPack add-on, which provides a portable user interface and additional functionality for the device. The PortaPack add-on includes a touchscreen display, a battery pack, and various software applications, including a spectrum analyzer and digital decoder, a signal generator, radio jamming, and much more.
ADALM-Pluto
The ADALM-Pluto is developed by Analog Devices Inc as a hands-on platform for learning about SDR and wireless communication. It is based on the Analog Devices AD9363 RF transceiver chip, which provides two independent TX & RX channels with a frequency range of 325 MHz to 3.8 GHz (firmware can be modified to extend the frequency range up to 70 MHz – 6 GHz, Bandwidth up to 56 MHz and Sample rate up to 61.44 MSPS). The platform also includes a Xilinx Zynq-7010 FPGA, which provides the processing power required for implementing various wireless communication protocols. It is designed to be used with software applications like GNU Radio, MATLAB, and Simulink. It has become popular among amateur radio enthusiasts since it can be used to uplink to QO-100 satellite’s narrowband transponder to make contacts or transmit DATV to its wideband transponder.
LimeSDRs, BladeRF x40, and Ettus B210
These devices are expensive yet rather powerful and high-performance software-defined radios meant to use as lab equipment to conduct experiments, set up base stations for Wi-Fi, Bluetooth, and cellular networks, run simulations, and conduct in-depth signal analysis, explore and research wireless communication systems. They all have powerful FPGAs, programmable logic gates, and configurable GPIO for experimentation purposes. They usually require additional components and calibration to function correctly. They can be used for amateur radio projects as well that demand more performance, more accuracy, or more stability.
Special purpose SDRs
There are some other SDR projects, which are built focused on more specific use cases or for a specific field of study such as KrakenSDR, CaribouLite RPi HAT, Maverick-603, SOCORAD32, iotSDR, AntSDR E200, AIR-T, XTRX and much more new projects starting every day. We will talk about a few of those projects in future articles.
Future of SDRs…
SDR technology has had a positive impact on HAM radio. It has made HAM radio more flexible, improved its performance, and made it more cost-effective, and accessible, allowing HAM radio operators to use a single radio for multiple purposes. With SDR, the radio’s functionality can be changed by simply updating the software. This flexibility allows HAM radio operators to experiment with different modes and frequencies without having to purchase multiple radios. They usually have better sensitivity, selectivity, and dynamic range than traditional radios. Additionally, they are less expensive than traditional radios, and they offer more features. This means that HAM radio operators can get more for their money. Most importantly software-defined radios are easier to use than traditional radios, and they require less technical knowledge. This means that more people can get involved in HAM radio.
Lately, popular manufacturers like Icom and Yaesu have released transceivers based on SDR technology, and they have become increasingly popular among amateur radio operators due to their flexibility and versatility. Icom has a range of SDR transceivers, including the IC-7300, IC-7610, and IC-9700. The IC-7300 is a popular entry-level SDR transceiver that offers a range of features, including a large color touchscreen display, a built-in antenna tuner, and USB connectivity. It covers the HF bands from 1.8 MHz to 50 MHz, and it has a power output of up to 100 watts. The IC-7610 is a more advanced HF/50Mhz SDR transceiver with dual tuners and 200 watts of output power. The IC-9700 is an SDR transceiver that is designed for VHF and UHF operations. It covers the VHF and UHF bands from 144 MHz to 430 MHz and supports D-STAR digital voice and data modes. It has a power output of up to 100 watts. Yaesu also has its own range of SDR transceivers, such as the FTDX101D, FTDX101MP, and FTDX10. They are all designed for HF bands with different power output levels.