Review: Airspy vs. SDRplay RSP vs. HackRF
IMPORTANT NOTE: Please note that this review is now out of date as the SDRplay RSP line has received significant improvements to their hardware and Airspy have brought out a new SDR that is much better at HF.
Overall it is now difficult to pick a winner between Airspy and SDRplay products. However, our preference is the Airspy HF+ Discovery for HF signals, and the SDRplay RSP1A for generic wideband wide frequency range receiving.
When people consider upgrading from the RTL-SDR, there are three mid priced software defined radios that come to most peoples minds: The Airspy (store), the SDRplay RSP (store) and the HackRF (store). These three are all in the price range of $150 to $300 USD. In this post we will review the Airspy, review the SDRplay RSP and review the HackRF and compare them against each other on various tests.
Note that this is a very long review. If you don't want to read all of this very long post then just scroll down to the conclusions at the end.
What makes a good SDR?
In this review we will only consider RX performance. So first we will review some terminology, features and specifications that are required for a good RX SDR.
SNR - When receiving a signal the main metric we want to measure is the "Signal to Noise" (SNR) ratio. This is the peak signal strength minus the noise floor strength.
Bandwidth - A larger bandwidth means more signals on the screen at once, and more software decimation (better SNR). The downside is that greater CPU power is needed for higher bandwidths.
Alias Free Bandwidth - The bandwidth on SDR displays tends to roll off at the edges, and also display aliased or images of other signals. The alias free bandwidth is the actual usable bandwidth and is usually smaller than the advertised bandwidth.
Sensitivity - More sensitive radios will be able to hear weaker stations easier, and produce high SNR values.
ADC - Analogue to digital converter. The main component in an SDR. It samples an analogue signal and turns it into digital bits. The higher the bit size of the ADC the more accurate it can be when sampling.
Overloading - Overloading occurs when a signal is too strong and saturates the ADC, leaving no space for weak signals to be measured. When overloading occurs you'll see effects like severely reduced sensitivity and signal images.
Dynamic Range - This is directly related to ADC bit size, but is also affected by DSP software processing. Dynamic range is the ability of an SDR to receive weak signals when strong signals are nearby. The need for high dynamic range can be alleviated by using RF filtering. Overloading occurs when a strong signal starts to saturate the ADC because the dynamic range was not high enough.
Images/Aliasing - Bad SDRs are more likely to overload and show images of strong signals at frequencies that they should not be at. This can be fixed with filtering or by using a higher dynamic range/higher bit receiver.
Noise/Interference - Good SDRs should not receive anything without an antenna attached. If they receive signals without an antenna, then interfering signals may be entering directly through the circuit board, making it impossible to filter them out. Good SDRs will also cope well with things like USB interference.
RF Filtering/Preselection - A high performance SDR will have multiple preselector filters that switch in depending on the frequency you are listening to.
Center DC Spike - A good SDR should have the I/Q parts balanced so that there is no DC spike in the center.
Phase Noise - Phase noise performance is determined by the quality of the crystal oscillators used. Lower phase noise oscillators means better SNR for narrowband signals and less reciprocal mixing. Reciprocal mixing is when high phase noise causes a weak signal to be lost in the phase noise of a nearby strong signal.
Frequency Stability - We should expect the receiver to stay on frequency and not drift when the temperature changes. To achieve this a TCXO or similar stable oscillator should be used.
RF Design - The overall design of the system. For example, how many lossy components such as switches are used in the RF path. As the design complexity increases usually more components are added to the RF path which can reduce RX performance.
Software - The hardware is only half of an SDR. The software the unit is compatible with can make or break an SDRs usefulness.
Next we will introduce each device and its advertised specifications and features:
Device Introduction and Advertised Specifications & Features
|Airspy||SDR Play RSP||HackRF|
$199 / $ 249 USD (with Spyverter) + shipping ($5-$20).
As of April 2016, the Airspy Mini is now also for sale at $99 USD.
$149 USD + shipping ($20-$30 world, free shipping in the USA)
£99 + VAT + ~£10 shipping for EU.
|$299 USD + shipping|
|Freq. Range (MHz)||24 - 1800
0 - 1800 (with Spyverter addon)
|0.1 - 2000||0.1 - 6000|
|ADC Bits||12 (10.4 ENOB)||12 (10.4 ENOB)||8|
10 (9 MHz usable)
6 MHz (5 MHz usable) (AS Mini)
|8 (7 MHz usable) (10 MHz in SDRuno/~9 MHz usable)||20|
|TX||No||No||Yes (half duplex)|
|Dynamic Range (Claimed)(dB)||80||67||~48|
|Clock Precision (PPM)||0.5 PPM low phase noise TCXO||10 PPM XO||30 PPM XO|
|Frontend Filters||Front end tracking IF filter on the R820T2 chip.||8 switched preselection filters + switchable IF filter on MSI001 chip||Two very wide preselection filters - 2.3 GHz LPF, 2.7 GHz HPF|
|ADC, Frontend Chips||LPC4370 ARM, R820T2||MSi2500, MSi001||MAX5864, RFFC5071|
|Additional Features||4.5v bias tee, external clock input, expansion headers.||LNA on the front end||5v bias tee, LNA on front end, external clock input, expansion headers.|
The Airspy is designed by Benjamin Vernoux & Youssef Touil who is also the author of the popular SDR# software.
Of note is that there has been a misconception going around that the Airspy is an RTL-SDR/RTL2832U device. This is not true; there are no RTL2832U chips in the Airspy. The confusion may come from the fact that they both use the R820T2 tuner. The RTL2832U chip is the main bottleneck in RTL-SDR devices, not the R820T2. When coupled with a better ADC, the R820T2 works well and can be used to its full potential.
The Airspy team write that they sell units mostly to universities, governments and professional RF users. However, they also have a sizable number of amateur users.
Update: As of April 2016 the Airspy Mini is now for sale for $99 USD. The main difference is a 6 MHz bandwidth and fewer expansion headers, but all other specs appear to be the same.
The SDR Play Radio Spectrum Processor (RSP) is designed by UK based engineers who appear to be affiliated with Mirics, a UK based producer of SDR RF microchips.
The chips used in the SDRplay RSP are dedicated SDR chips which were designed for a wide variety of applications such as DVB-T tuners. The RSP uses these chips and improves on their front end capabilities by adding an LNA and filters in order to create a device capable of general SDR use.
Initially when writing this review we had deep problems with the imaging of strong signals on the RSP. However, a recent Dec 22 update to the drivers has fixed this imaging problem tremendously.
The SDRplay is currently selling about 1000 units a month according to electronicsweekly.com.
The HackRF is designed by Micheal Ossmann a computer security researcher who was given a development grant from DARPA. His company is called "Great Scott Gadgets".
The HackRF's most unique feature when compared to the other two SDR's is that it is capable of both receiving and transmitting.
There is also a clone called the HackRF Blue out on the market which is about $100 cheaper, but they don't seem to have stock or be producing these any more.
From the specs it is clear from the ADC sizes that both the Airspy and SDRplay RSP are in a different class of RX performance when compared to the HackRF. However, people always compare the Airspy and SDRplay with the HackRF due to their similar price range, so we will continue to compare the three here in our review, but with more of a focus on comparing the Airspy and SDRplay RSP.
In order to use the Airspy on HF (0 - 30 MHz) frequencies a $50 add on called the Spyverter is required. This is an upconverter that is designed for use with the Airspy's high dynamic range and bias tee power port. However, one hassle is that the Spyverter must be connected/disconnected each time you want to switch between HF and VHF/UHF reception as it does not have VHF/UHF passthrough. The RSP and HackRF on the other hand can receive HF to UHF without the need of an upconverter or the need to change ports. A single port for HF to UHF can be very useful if you have a remote antenna switcher.
Post continues. Note that this is a long post with many images.
System Hardware Requirements
Requires a fast modern PC. The Airspy website suggests at least a 3rd gen Intel i3 2.4 GHz processor. The creators have also suggested elsewhere to look up your CPU score on PassMark and ensure that your CPU score is above 3500.
You will also need to ensure that you have a high quality high speed USB 2.0 port and controller. Some controllers are known to be buggy and are unable to provide the full required bandwidth. Update your USB drivers if you have issues.
Requirements can be reduced slightly by using the "bit packing" feature of the Airspy.
Overall CPU requirements are much higher than the other two options because the Airspy only supports a 10 MSPS (10MHz) sample rate. There is a 2.5 MHz sample rate available, but they write that it may not operate that well at the moment. The Airspy also uses a different USB mode of operation compared to the RSP, which requires greater CPU power.
No requirements are given, but we estimate that minimum specs are significantly lower than what is needed by the Airspy.
The RSP also supports various smaller bandwidths which can reduce CPU requirements.
From online reports it seems to run fine on older PC's like Core2Duos, though the maximum sample rate may be restricted.
No specific requirements given, other than the need for a good Hi-Speed USB Port for running the HackRF at higher sample rates.
At the highest sample rate of 20 MSPS we estimate that CPU requirements similar to the Airspy are needed.
Initially when writing this review we had trouble running the Airspy on our main PC at its largest bandwidth of 10 MHz. There was significant crackling and jitter on the spectrum due to lost packets. Either our older Intel i5-750 2.67 GHz CPU (passmark 3732 but overclocked to 3.33 GHz) is not fast enough for this high amount of data, or our USB chipset is not good. After updating the USB drivers to the latest version the problem improved, but stuttering was still present. Our problems were solved when we discovered the bit packing feature. With this feature enabled the Airspy worked fine at 10 MHz. This feature reduces the amount of data needed to be transferred by packing the bits resulting in less data transfer for the same results. We also tested the Airspy on a more modern Intel i5-3470 @ 3.2 GHz with passmark score of 6568, and it ran perfectly at 10 MSPS without the need for bit packing, but strangely this CPU saw dropped packets when bit packing was turned on. An Intel i7 laptop on the other hand had no problem running the Airspy with bit packing off. On an i5-4200U @ 1.60 GHz CPU (passmark 3280) laptop the Airspy stuttered even with bit packing turned on.
The RSP worked fine on all the PCs that we tried on (all i5 and i7's mentioned above) and it ran well at the highest rate of 8 MHz.
On our i5-750 and i5-4200U CPUs we were unable to run the HackRF at 20 MHz without significant crackling and jitter on the spectrum due to lost packets. At the next lowest setting of 16 MHz it ran fine. On the i5-3470 the HackRF ran fine at 20 MHz.
We monitored the USB usage using Windows performance monitor and discovered that the Airspy (with bit packing at 10 MHz) used 30,000,000 bytes per second, the RSP (at 8 MHz) 25,000,000 bytes per second and the HackRF (at 20 MHz) 40,000,000 bytes per second.
After showing a draft of this review to the SDRplay team, it was mentioned to us by them that the main reason that the RSP works well on older hardware is its use of an "isochronous mode" USB driver which is in contrast to the Airspy's "bulk mode" driver. An isochronous driver reserves the necessary USB bandwidth, whereas a bulk mode driver does not. Thus there is a greater risk of packet loss with a bulk mode driver. However, the disadvantage of an isochronous driver is that there is no means to know how many samples were lost if the system has a transfer error. This means that with an isochronous driver it is impossible to implement coherent receivers, which is one of the Airspy's use cases with it's external clock input.
We also note that the Airspy sends raw ADC samples to the PC and then must do the IQ conversion on the PC. In low IF mode the RSP does the same, but in Zero IF mode it sends IQ data.
Physical Appearance and External Design
|Dimensions||5.3 x 2.5 x 3.9 cm||9.7 x 8.0 x 3 cm||12.2 x 7.6 x 1.7 cm|
|Weight||65 g||110 g||100 g|
|Ant. Connector||SMA||SMA (F-Type on older units)||SMA|
|USB Connector||Micro USB||USB B||Micro USB|
|Additional Connectors||MCX CLKIN connector||None||SMA F for CLKIN and CLKOUT|
|Buttons||None||None||RESET and DFU (Firmware flash) buttons.|
Previous versions of the SDR Play (like our purchased unit) used an F-Type antenna connector.
The Airspy is the smallest device with the SDRplay and HackRF being close to the same size.
With RF devices a good enclosure is recommended to help keep any strong RF interference out of the signal path. A conductive metal enclosure is best so that a faraday cage is created. Out of the three units, only the Airspy comes with an aluminium enclosure, and a good electrical connection is made to the enclosure via a nut on the SMA connector and through edge tracks on the PCB. The HackRF and RSP both come in plastic cases and so have no shielding.
All three SDR's use a standard SMA connector. Previous versions of the RSP, like the unit we used in this review came with F-Type connectors. We don't like the F-type connector because it is less commonly used in the radio field and it has poorer RF insertion loss properties, so it is good to see that they changed the connector in the newer versions. There were no other changes to the RSP in the upgrade apart from the case and connector, so we believe this change should not significantly affect the review.
We're not fans of the micro USB ports used on the Airspy and HackRF as they tend to easily cause loose connections with a bit of movement, but due to size constraints we understand why they were used. The HackRF does indeed sometimes disconnect when we move the cable or device around without care, but we have not had this trouble with the Airspy. Micro USB connectors are also easily broken off PCBs with cable strain, however the Airspy and HackRF casings appear to provide adequate strain relief. We also note that Airspy R2 also has a vastly improved micro USB connector that is through hole mounted onto the PCB and looks almost impossible to break. Regardless, as with any connector we would advise against applying too much strain.
The USB B connector on the RSP is sturdy and does not easily come loose. It is also easier to find high quality shielded USB cables with USB B connectors.
The Airspy and HackRF both have external clock inputs. This allows these devices to be used with more accurate clocks, such as GPS synchronised ones. It also allows them to be used as coherent receivers (many receivers using the same clock source) for various applications such as doppler direction finding and passive radar setups.
Installation and ease of use for general frequency browsing on Windows
Installation involves simply plugging the Airspy into the USB port of the PC and letting Windows plug and play automatically install the drivers. The user can then open up SDR#, select Airspy from the menu and push start.
Setting up the RSP first requires installation of it's drivers from the SDRplay website. As the RSP has no official software, the second step requires the installation of a plugin for SDR#, or other supported software such as HDSDR. The entire set up procedure is simple, but it is not plug and play.
|Installation on Windows is similar to installing an RTL-SDR. Just run zadig and install the WinUSB driver for the HackRF. Then it can run on Windows with SDR#.|
In this review we installed all three SDRs from scratch. All the SDR's were easy to install on Windows, but the Airspy was the easiest with its plug and play operation.
Native compatibility with SDR# on Windows. Also compatible with HDSDR, SDR-Console and GQRX on Linux. Good support for some other software that is most often used with the RTL-SDR:
Also has unofficially developed ExtIO interface allowing it to work with any app supporting ExtIO. For example:
Good support for the Raspberry Pi 2, especially for ADS-B where they have developed an official 20MSPS ADS-B decoder which claims performance as good as or better than a dedicated Beast ADS-B receiver.
Linux and Mac open source drivers available, but no SDR# support.
June 2016: Now comes with the official SDRuno software.
Compatible with SDR#, HDSDR and SDR-Console through plugins. Though compatibility with SDR# is restricted as third party plugins cannot be used. The RSP is also compatible with any app supporting ExtIO. For example:
Linux drivers available and plugins for SoapySDR, CubicSDR, Pothos and GNU Radio are available.
CubicSDR also runs with the RSP on the Mac.
Eventual improved support planned for Raspberry Pi 2 and Android.
Compatible with SDR#, HDSDR and SDR-Console on Windows, GQRX on Linux and RF Analyzer on Android.
Several programs in code form on GitHub, but not many "plug and play" apps. Designed to be used more with software like GNU Radio.
One advantage to using the Airspy with its SDR# software is the "decimation" feature. With wideband SDR's it can be difficult to spot or tune into narrowband signals. You can use the zoom feature, but when zooming you lose resolution. The decimation feature reduces the visible bandwidth, but keeps the resolution high, allowing weak signals to be easily discerned from the noise. An added bonus is that the effective number of ADC bits is increased with decimation, meaning that signals can have higher visual SNR (full audio decimation is performed automatically). This makes the Airspy very good at browsing and fine tuning on small narrowband signals.
The SDRplay RSP can achieve a similar effect by reducing the bandwidth displayed, however this means that a lower sample rate is used, and thus less decimation occurs.
The SDRplay and HackRF do not have the decimation software feature yet, though the SDRplay team write that they have the decimation feature scheduled for an upcoming API update. The RTL-SDR has this feature through a third party plugin written by Vasilli so it seems feasible that this feature can be easily implemented.
Estimated Bill of Materials Cost
These are just very rough guesses and they could be wildly inaccurate. Note that these costs are for parts only, and they do not take into account manufacturing costs, engineering time costs and support staff overhead costs etc.
|Airspy||SDR Play RSP||HackRF|
LPC4370 ~ $8
SI5351C ~ $3
R820T2 ~ $1?
Other components, connectors, passives, PCB, case, cable etc ~$25
Total Cost ~$37?
Mirics FlexTV dongle (dongle uses the same MSi001 and MSi2500 chipsets as the RSP) claimed $5 BOM.
Filters + Switches ~$10
Connectors, Passives, PCB, case ~$10
LNA ~ $1
Total Cost ~$26?
MAX5864 ADC~ $6
RFFC5072 Mixer ~$13
LPC4320FBD144 Processor ~ $5
XC2C64A-7VQG100C FPGA ~ $3
Switches ~ $10
SI5351C ~ $3
Other components, connectors, passives, PCB etc ~$20
Total Cost ~ $70?
|Airspy||SDR Play RSP||HackRF|
The RF chain in the Airspy goes Input -> R820T2 -> LPC4370.
The LPC4370 has a 12 bit ADC.
The website claims a NF of 3.5 dB and an IIP3 of 35 dBm. However this noise figure is probably taken at maximum gain, and the IIP3 taken at zero gain.
The Airspy does not have preselectors, apart from an internal IF filter in the R820T2 chip.
It seems that the design approach of the Airspy is to optimize for signal linearity and to avoid overloading through natural high dynamic range.
The RF chain in the RSP goes Input -> Switch-> MGA-68563 LNA-> Switch -> Filter -> MSi001 -> MSi2500.
The MSi2500 has a 12 bit ADC
The RSP is designed with switching RF filters and an MGA-68563 LNA right at the front end which is only active for signals that are above 60 MHz. The MSi001 tuner chip has a second LNA inside it. The MGA-68563 is used as a preamp to overcome the losses in the filters and presumably to lower the noise figure of the internal MSi001 tuner LNA's. The MGA-68563 has a 1 dB noise figure, 19.7 dB gain and a 20 dBm OIP3.
According to the SDRplay team the MSI001 has a NF of around 4.5 dB in VHF and UHF mode.
The RSP has 8 switched front front end filters that are automatically selected, as well as an adjustable IF filter inside the MSi001 chip which can help to overcome interference from strong in band signals. To use this internal filter the IF bandwidth must be reduced in the RSP configuration screen. This means that when reducing the IF filter size you will see less that 8 MHz.
In conclusion it seems that the SDRplay tries to optimise itself for sensitivity by using a front end LNA, and focuses more on overcoming the effects of overloading via switched filter banks.
The RF chain in the HackRF is much longer longer and more complex. The front end goes Input -> Switch -> MGA81563 Amp (optional) -> Switch -> Switch -> Switch -> LPF/HPF -> Switch -> Switch -> RFFC5072 Mixer -> Switch -> Switch -> MAX2837 -> MAX5864 ADC -> LPC43XX processor.
The MAX5864 has an 8 bit ADC.
In order to get the HackRF to perform over such a wide range and to RX and TX, many diode switches are placed into the RF chain. Each of these switches causes a 0.35 - 0.5 dB signal loss which can explain why the HackRF has fairly poor sensitivity.
The HackRF also has no real filtering, but technically there is a 2.3 GHz LPF and a 2.7 GHz HPF.
In conclusion the HackRF has rather poor RX specs, with only an 8 bit ADC and several lossy switches.
We are of the opinion that adding an extra LNA right at the front end of a receiver (like what is done on the RSP and HackRF) is generally a bad idea. This is because an LNA at the front end will not reduce the noise figure as much as an external LNA placed near the antenna would. Additionally, if there is a built in LNA placed near the front end, then this ruins the system for optimal performance if an external LNA were to be used. If we were to place a second LNA near the antenna to overcome coax losses, then the linearity (IP3) of the system would be further degraded due to the additional internal LNA, possibly resulting in more overloading and intermodulation. The RSP designers decided to add an extra LNA at the front end to overcome the preselector filter insertion loss, but we think perhaps adding a bias tee and supplying an external LNA would have been better for performance, although more cumbersome. The option to bypass the front end LNA during operation would also be beneficial.
See this previous post for more information on proper LNA placement.
Each SDR has its gain and sample rate controlled through an on screen interface. Here we review the Airspy, SDRplay RSP and HackRF control interfaces.
The Airspy can run in sensitivity, linearity or free mode. The sensitivity and linearity modes simply choose an optimal set of values for the IF/Mixer/LNA gains which can be controlled manually in free mode. The sensitivity mode uses more gain on the LNA which can come at the expense of reduced linearity and thus more intermodulation. The Linearity mode uses less LNA gain, and more IF/Mixer gain which can reduce intermodulation, but at the expense of a few dB's of SNR. The Airspy quickstart guide suggests the following procedure for setting the gain:
- Start with the minimum gain
- Increase the gain until the noise floor rises by about 5dB
- Fine tune to maximize the SNR (the bar graph on the right)
The sample rate drop box allows you to choose between the two sample rates available for the Airspy which are 10 MSPS and 2.5 MSPS. The 2.5 MSPS option is still experimental and is known to have USB noise problems on some PCs.
The decimation feature allows you to reduce the visible bandwidth while at the same time increasing the visible SNR. This allows you to easily spot and tune into weaker signals.
The Bias-Tee check box allows you to turn on the 4.5V bias tee. The SpyVerter option automatically sets the frequency offset to -120 MHz for easy operation with the SpyVerter upconverter.
There is no option to set the PPM offset (the PPM box is for adjusting the Spyverter upconverter only) as the 0.5 PPM TCXO used on the Airspy should not need any offset adjustment.
For the SDRplay we used a beta version of their SDR# 1400+ plugin for their latest API which fixed most of the RSP's imaging problems. It was a beta released just to us to do this review sooner so it was a little buggy in terms of crashes, but we stress that this is not the case for the officially released plugins. SDRplay recommend using their ExtIO plugin instead, but to get fair comparison screenshots we wanted to use the same SDR# version on both Airspy and RSP tests. To be sure the plugin wasn't affecting RX results we compared it to their officially released ExtIO plugin for older versions of SDR# and HDSDR and we saw no changes in terms of signal performance.
The gain tuning method used by the SDRplay is a little different compared to most SDRs like the Airspy and the HackRF. Here instead of tuning by adding gain, they use a gain reduction (GR) method which reduces the gain by some amount from the total available gain. As you adjust the gain slider amplification in the mixer and IF stages change automatically.
There is also the option to toggle on or off the internal Mirics chip LNA. This is the LNA in the tuner chip, and not the front end LNA which is always on for VHF+ frequencies. Turning this LNA on can help to reduce the noise floor, but also may cause additional imaging problems.
If you prefer to use the automatic gain control (AGC) then you can control the "setpoint" value which will try and keep the noise floor at the specified value.
In the IF Amplifier section you can also choose between Zero IF and Low IF modes. The Low IF mode appears to produce less unwanted images, however if the Low IF mode is selected then the largest bandwidth available is 1.536 MHz. The IF bandwidth setting lets you specify the size of the IF filter used in the MSI001 chip. Setting a lower value will reduce the amount of visible bandwidth, but can help to block out in band interferers.
The ADC sample rate can also be adjusted independently of the IF bandwidth, but must be equal to or larger than the IF bandwidth.
The HackRF has only two gain slider control options, LNA and VGA, but there is also an option to enable the MGA-81563 front end amplifier with the Amp check box.
The sample rates available are 8, 10, 12.5, 16 and 20 MSPS.
Real world tests continued on the next page.
Great forum that I wished I had discovered earlier, better late than never !
Enjoyable product review but is there an SDR on the market that offers Tx and the wide bandwidth of the HackRF but with the performance quality of the AirSpy, please ?
If I had multi thousand livres available I would love to own a Yaesu or similar piece of kit but as I don’t have that kind of loose change and radio Ham being new to me even though I have had a lifelong interest only now being realised I feel that SDR is the way to go until I am positive that this is for me.
Thank you in anticipation of your reply.
I know this center spike in ZeroIF is by design either in the SDRplay API or the hardware. This is not an issue with my Airspy Mini.
SDR++ v1.0.4 was released today allowing Low IF mode which got rid of the center spike issue with my RSP units. Working good so far using “LowIF 2048Khz, IFBW 5000KHz”. I wish the spike was not present using ZeroIF mode though.
hackrf is deaf
I find sample rate to be a negligible feature which I don’t tend to consider when purchasing software defined radios. The reason behind this simple; firstly, my computers aren’t the fastest in the world and thus can not process the amount of data that larger sample rates incur. Secondly, I like to easily visualize strong signals across the visible spectrum. I find it’s easier to home in on signals with a 2 mega-samples per second rate. The only exception to the rule is while homing in on WFM signals, the signal width counteracts larger sized sample rate.
With regards to RSP1A versus HackRF One; It’s like comparing a Ferrari to a Porsche. They are two very good SDRs and they perform very well. On one hand, the HackRF One supports the Portapack H1 add-on, which now can be loaded with the Mayhem firmware. I find this configuration to be extremely portable, depending on antenna choice.
To put it in more simple terms… I think the SDRPlay performs well as my base station setup while my HackRF One performs well in mobile situations. To anyone considering purchasing either of these, please consider the cost. I think the SDRPlay has far better value for money.
Excellent review, thank you. This is probably the best comparison between SDRplay and AirSpy on the web. It would nice if you could revisit this article and update it with newest SDR: Airspy HF+ Discovery and SDRplay RSPdx. It would be nice to compare their performance now.
So, I have an RTL-SDR and really want the best SWL SDR…I am planning it life to be spent as a backup rcvr to my amazing KX3 Elecraft and as a loaner for those wanting to “listen in” to ham radio. Suggestions please.
I have a 100% Grade-AAA MINT Drake R8-B with VHF card and Drake MS8 external speaker that have been sitting in a closet for 15 years…I would sell for a respectable sum that appreciates their condition (perfect).
I have a problem with the dongle shutting off by just barely bumping the computer or when I’m in the car u barley touch it and it goes off this is the most frustrated thing otherwise everything ok. Keep in it running is most important to me.
Use a USB extension cable to stabilize the dongle.
My choice here is SDRplay for one reason: usability.
Currently I use an RTL-SDR dongle with an upconverter that has a bypass feature. Going from HF to VHF/UHF I just have to flip a switch on the converter, but I can’t remember how many times I stared at a screen with no signal until I realized I forgot to flip that darned switch. Or forgot to enabled/disable the offset in SDR#, dialing in the wrong frequency. With SDRplay that won’t happen.
Regarding Airspy: do they really expect me to (un)screw that converter every time I change HF/VHF? No way.
I am new to the SDR era. Started listening on a Zenith TransOceanic that my mother had bought in the late 40s. Eventually, as a high school student, I got a 12 tube superhet receiver. Later a Sony 2001. Still later a Techsun PL-380. Now I got a RTL-SDR (RTL2832U). Considering an SDRplay 2, mainly because I like LW and SW. Thanks for the review. I would love to see the comparison include SDRplay2.
Kudo to the reviewer. I find your work very useful indeed!
Two questions that I would appreciate if you could reply:
– Did you test Airspy, or Airspy R2 (the manufacturer claims the R2 version to have better USB noise rejection).
– At the beginning of the article, you wrote: “Initially when writing this review we had deep problems with the imaging of strong signals on the RSP. However, a recent Dec 22 update to the drivers has fixed this imaging problem tremendously.”. Do the test reports in this article refer to the SDRplay with the updated drivers, or without?
I feel really dumb, but….
How do I get the HF functions working in gqrx under Linux? Presumably I need some new drivers. From where? And does gqrx support this?
HF functions for which of these SDR’s? It should just work for the sdrplay and hackrf, but for the Airspy+Spyverter you’ll need to set the offset to 120 MHz.
May I ask why every single hack rf test graphic shown the noise floor is consitently higer than each of the other two with the airspy always having the lowest noise floor? Are you guys affiliated with any of these SDRs?
There is an 8-bit ADC in the hackrf (and debug mode output from rtl-sdr dongles) which will provide a dynamic range of 49.92dB, but there is a 12-bit ADC in the airspy and sdrplay which provide a dynamic range of 74dB. So the sdrplay and airspy should have a lower noise floor than the hackrf. Having a higher dynamic range is useful if there are really strong signals right beside the weak signal that you are interested in. If there is not then you can just adjust the gains to bring the signal you are interested in within the window of your dynamic range. Or if needed you could decimate and have ~3dB of additional of dynamic range every time you half the bandwidth – basic DSP 101.
As mentioned in the review the HackRF is simply in a lower league of RX quality, and we shouldn’t really have to compare it with the SDRplay and Airspy. But many people in the past have always incorrectly suggested that the HackRF would be the best upgrade to an RTL-SDR, and questioned why would you pay $200 for an Airspy or SDRplay when you can spend a little more and get a HackRF which can TX. This is bad advice for those who mainly want to RX and need high dynamic range to pull out those weak signals. So we thought we’d add the HackRF in too so the comparison of RX quality is clear.
This is not to say the HackRF is bad, it just has a different purpose – the TX capability is of course very useful.
I find the article very well done and in many instances, a good reference.
The thing to remember is value. For the money I believe the SDRplay is the better investment.
I have added an LPF board from an TS-180S and a RTL/SDR SUB-LNA from JaniLab in Hungary.
This greatly improves sensitivity and image rejection. I have just started with the new software, but because I share my SDRplay, I continue to use SImon Brown’s software on a regular basis.
Above all…consider Omni-Rig and enjoy parallel tracking for smooth contesting on less expensive radios. I use the FT-DX-1200 with my SDRplay.
So as a noob with a $10 generic RTL dongle and a free copy of Cubic, who is ready to take this SDR stuff to the next level, what is the takeaway? I’m ready to buy, but I’d prefer to buy once. Airspy seems to be the winner but… My primary interest is in SWL – news from the other side of the world. I also live next to a very active USAF base and would like to listen in on their comms, and I’m on the coast so we’ve got a lot of Coast Guard and marine traffic as well. I landed here in the process of doing my homework before I buy, and until reading this I was leaning towards a NooElec dongle with the Ham it Up upconverter and a LNA4ALL as my rig. PS – I’m settled on a Par endfedz longwire to replace my homebrewed POS unless someone has a better suggestion.
TIA – Bill
I’m on the same opinion. As for starters, I picked the NESDR Smart dongle and a balun 9:1 from Nooelec that seems to be an affordable choice, but for the upconverter I was also interested in the Ham It Up, but I does not seem to go well on the comparation tests. I wonder if the spyverter is a good choice to match my NESDR SMART. Altough the T bias line feeding will not work. And the Tuner will not have the same bits resolution of the more expensive choices as AirSpy. It seems awkward to spyverter not even have a bypass swith as ham it up does. Does anyone have tested this combination NESDR + Spyverter?
Please check SDRPlay receiver, on a plot of 400-420 and 220-300. In the region of 400-420 I can’t hear almost anything at all. In the area of 258 MHz I don’t hear the SATCOM. Although another receiver on the same antenna hears. If anyone has the opportunity, please check the reception quality of 400-420 and 220-300 MHz. Above 300 MHz is no problem, everything works fine. Also works well aviation, 150-170, 420-470 and so on.
Found this review to be very helpful; many thanks! Just an FYI have used the HackRF One on the AM broadcast band (540 – 1600 KHz) and it receives the full spectrum very well (using a 43 foot vertical outdoor antenna). Can use SDR# and SDR Console, both are compatible with the HackRF One. Very easy to set up, similar to SDR dongle; run the Zadig driver, download SDR# or SDR Console and you are up and running. As with all receivers, a good antenna is the sine qua non for optimal reception, outdoor is better, higher is better, and bigger is better hi hi. Also, a pre-selector like the MFJ-956 or similar will help along with judicious use of the RF gain.
Kudos to GreatScottGadgets (HackRF One), SDR# folks, SDR-Radio (SDR Console), and Carl (RTL-SDR.com) for the great products, software, and technical information to keep the hobby evolving.
Agree totally with br0band, the length and content of your review is perfect. Thanks very much!
I like most parts of your review. The only thing i dont like: you are compairing a 20 MSPS sampler (HackRF) with two ~8 MSPS samplers using SDR#. This is TOTALY WRONG. From a digital signal processing point of view you only can compare samplers if their sampling rates a equal to each other. For your review this means, that you have to upsample or downsample in many cases befor doing the measurement.
In other words: comparing 20 MSPS and 8 MSPS samplers to each other is only possible by
a) downsampling from 20 MSPS to 8 MSPS and compare to 8 MSPS samplers (which can not be done in SDR# or
b) upsampling from 8 MSPS to 20 MSPS and compare to 20 MSPS (which can not be done in SDR#)
Actually in the HackRF tests we use it’s 8MSPS sampling mode only. The Airspy uses 10MSPS and the RSP 8MSPS. Since 10 and 8 MSPS is not very different, we just interpolate the SNR readings by adding 1.2dB to the Airspy to factor out the FFT bin density differences.
Ideally we’d run the HackRF at 20MSPS and downsample to 8MSPS or lower to achieve decimation improvements, but the HackRF or SDR#, (or any other software except for DSP languages like GNU Radio) provides no means for doing so.
That is One Real Good Analysis! I now know pretty much everything that there is to know about these 3 units. Constructive comment: I really wished you had included the R820T2 RTL2832U SMA Dongle as a forth compared item. I know very well that the specifications are not of the same level. Obviously a $25 unit cannot compete with a $150 to $300 SDR but it would have been fun to see how RTL2832 make it in this competition. Good job! Thanks!
Many thanks – I was missing a comparison like this for a long time … well done and it reflects a the a real life usage model which so many others miss out on – great job!
Finally (well probably not) what appears to be an objective in-depth review based on the real world with its hugely complex mix of signals. However for me what is missing is the image rejection performance. In the case of the SDRPlay – the zero IF image rejection and the image rejection in low IF mode. In the case of the AirSpy the low IF image rejection.
I can offer the following figures for SDRPlay using API 1.8.1 which has in built I/Q balancing. Zero IF image rejection around 60 dB and low IF image rejection with 2.048 Mbps sample rate wasabout 40 dB – the image appearing 4.096 MHz below. This on the FM broadcast band – FM DXing is my main interest and images falling on a weak DX signal is the last thing that we want.
I don’t own an Airspy and would like a solid ‘real world’ number for the low IF image rejection at 10mbps sample rate – it would need to be closer to 70 dB to make a purchase worthwhile – as my SDRPlay performs adequately and I need a significant improvement to warrant opening my wallet.
Out of interest I measured the low IF image rejection on an R820T2 dongle at 2.048 Mpbs sample rate at around 45 dB – better than the SDRPlay in low IF mode. Again in the FM broadcast band.
These are ballpark figures merely arrived at by reading off the peak signal strength for the main signal and comparing it top the peak signal strength of the image as shown on the SDR#.
Wish I could post a picture here. A picture tells a thousand words – they say 🙂
Just done my own S/n comparisons between my Airspy and SDRPlay on 163Mhz.
Same weak RF generate signal from a calibrated HP service monitor, same patch lead and same software (SDR#) with gain controls adjusted for best S/n on both front ends.
My SDRplay is significantly better than my Airspy.
Either my Airspy is slightly deaf, or something is a bit ‘screwy’ with the above review.
Would love for others to do similar comparisons.
Hey, email the pictures to us at [email protected] and i’ll upload them, or upload to imgur.com.
Can you do some tests on a range of frequencies? I’m curious to see the results.
I’m going to do some siggen SNR comparison tests too and add them to the review early next week. I don’t have an accurate siggen available at the moment, but I can use the HackRF to generate a tone on various frequencies and that should be stable enough to make relative comparisons. Hopefully Rick or someone else does some tests too and after we can compare to confirm. When testing – remember to shield the RSP. In some initial tests that I just did I noticed that the RSP results are skewed upwards by about 1-2 dB when it is unshielded, probably due to additive leakage through the plastic case.
But I think in theory the RSP should have better sensitivity on a lab test like this by maybe 2-5 dB because of it’s 1dB NF MGA-68563 front end LNA. The Airspy could probably catch up in SNR by using an LNA on its front end too, I may test that as well. But remember that in a real environment with several blockers (like in the review environment) the max SNR obtainable will be affected by other metrics like dynamic range, so I don’t think that SNR lab testing like this is a very good measure for real world performance unless you are in a quiet environment.
I think that the lab testing is the only test that can give us the real figures and performance. Sensitivity is only one test, so there are other tests that should be performed, selectivity, linearity, SFDR, two tones, multi tones, LO PN etc. Upon the mentioned measurements one can get a clear picture of how any receiver will perform in a desired environment.
The way the tests were performed in the article may be handy but far away from the precise because the readers are looking for the fraction of the dB. Such accuracy is difficult to get even in the lab sometimes not to mention problems using the external signals through the antenna where influence of the external factor may be significant and selective. Let say weak signal test where the QSB is present and even multiple reflections on the higher frequencies.
I see the main problem in testing the devices that are designed for different audience with different ideas and approach. Of course, it will be nice to have one unit combining the HackRF frequency range, Airspy linearity, RSP sensitivity, HackRF TX possibility, Airspy GUI and RSP filtering. But we do not have that on the low end market.
May be you fried your Airspy with ESD.
An RTL-SDR with a LNA will outperform the RSP in the lab any day. Does it make the combination a good receiver? Definitely not!
Most noobs (and also some old farts) seem to confuse s-meter and signal quality. Put your super RSP in the field with real signals and it will show its weaknesses like in this review.
I can understand the RSP crowd feel like raped after reading this article… HAHAHA
That’s ok Yousef you can stick to your crap Airspy that needs an up converter, ill stick to my RSP All-In-One box that needs nothing else and has people that actually help others.
Sorry to disappoint you dude. I’m not Youseff. But I genuinely think you have problem with that chap.
For your RSP: Eat shit 1 million flies can’t be wrong!
So you have a Lab and tested your theory out then.
Added some SNR lab testing to the review now. Would be good to see someone else’s results though too.
I would like to suggest separate reviews for receive-only hardware (Airspy, RSP, RTL dongles – including E4000, etc.) and SDR transceivers (HackRF, Flex series, etc.).
There should also be head-to-head comparisons of software, with each package reviewed while operating each hardware platform it claims to support. Then we will finally see comparisons of apples to apples.
YES PLEASE, please include always the Dongle (RTL-SDR at least) in those tests.
Everybody (I think) has one at home, so it will be great to see the benefits of the others, 8 or 10 times more expensive SDRs.
I have to add something to the fray – – While I love my HackRF Blue (which is no different from HackRF) the most glaring issue – to me – is the base support for the product. Try collaborating with anyone on their Facebook support page or other forums – – the KEY information for HackRF is nonexistent unless you’re in the handful of developers that have all the register addresses to perform the functionality of the HackRF. The source that’s out there is only a fraction of what you need to make it work. I’ve been to GitHub several times looking for ANYTHING that would give me some clue how to write transceiver code for the HackRF and you only find fragments of what you need and the rest of it is in someone’s head that you have no access to. I even wrote Michael Ossmann himself to ask the questions and never got a response. If the only thing you can use to operate the HackRF as a transceiver is GNU Radio Companion (which, luckily, works pretty well in its environment and compiled in Python) you would be screwed – – there are no other apps that I know of other than GRC that the HackRF can use to perform transceiver functions. You won’t find it in GQRX. You won’t find it in SDR#, and you sure as Hell won’t find it in HDSDR, too. NO APPS OTHER THAN GRC FOR TRANSMIT. So that pretty much locks you down to GRC and Linux under Ubuntu 15.0 and up. And there is no grassroots support for HackRF that I’ve noticed, too. I added transmit and receive functionality files (in GRC) to the HackRF Blue Facebook page and even gave instruction that I WANTED to see people IMPROVE ON WHAT I UPLOADED and. . . . . . . .NOTHING. NOBODY IMPROVED OR ADDED TO WHAT I PUT UP THERE. It just seems that they pulled down the files and played with them – that’s it. So I’m of the opinion that unless you’re in the ‘inner circle’ of HackRF development, you’re pretty much screwed. You WON’T find anyone doing cool things with HackRF at all. It’s a vast wasteland.
THAT’S WHY I WENT TO RED PITAYA AND I’M NEVER LEAVING. At least THEY are developing apps – – and REALLY GOOD ONES AT THAT – – to support the Red Pitaya for a FULL UP HF TRANSCEIVER. My plan is to produce an upconverter for Red Pitaya that will allow it to transmit U/VHF, too, longer term.
So, LONG LIVE RED PITAYA..!
Thanks for the input about the HackRF, and very interesting to hear that the Red Pitya is doing well. People have done a lot of things with the HackRF, but the code seems to have been mainly kept private. It’s a great tool for researchers and hackers, but for a ham or scanner, probably not.
I would just like to point out that the biggest problem with the HackRF Blue ($199 Clone) vs HackRF One ($299 Official) is that the HackRF Blue is no longer for sale! It looks like they stopped making them after the kickstarter. But on their website (hackrfblue.com) they have a registration form and it looks like they are going to be releasing more boards in April 2016.
I’m part of the HackRF Blue Facebook group and recently understood that there are some HackRF Blue boards that will be built and available by the April timeframe, too – so they’re still building them. Most of the builds happen in Asia and I’m certain that Gareth Hayes has been busy setting all that up (Gareth appears to be the primary force behind HackRF Blue and I have to admire that he’s making it cheaper so more people can get in and develop). But the whole HackRF movement is VERY MUCH under wraps. Unless you’re within that University ‘inner circle’ you’re not going to get much traction with HackRF. That makes it REALLY frustrating when it’s such a fine transceiver and the only tools you have are GNU Radio Companion on the transmit side. Compiling the GRC flow diagrams to Python code will get you part of the answer, but then you have to ‘roll your own’ interface and hope that it plays nice with the HackRF. If they’d just put the register functionality out there to program the HackRF, you’d see A LOT of people use it and it’d probably eclipse RTLs and even Red Pitaya…But they didn’t. They kept it locked up and those that really know the HackRF aren’t talking. So that’s why I went to Red Pitaya – at least that’s the CLOSEST thing there is to the HERMES/TAPR transceiver there is – it uses the same PowerSDR software to make it run and it plays A LOT like my former Apache Labs ANAN-10E ran (yeah, I sold mine recently because of that). Anyway, Red Pitaya is going to eclipse HackRF if they keep on going the way they’re going with development. There’s some SHARP people working it and all the source is out there to play with. It’s too bad…I really love that HackRF, but I won’t be controlled by trolls that won’t share their source on what’s supposed to be a ‘open source radio’…End of soapbox rant…73
Not Yousseff here.
But how could he resist having an attitude, if this review is presented by dozens of SDR# pictures as reference software? :-))
As the author of the post excuse himself in the diclaimer note, I will try to keep my comment short. Othervise this will be a long comment, even longer than the author post 🙂
I can recognise a lot of efforts to perform such a detailed test and to write the article but unfortunatelly this test can not bring the real light on the performance of the tested equiment simply because of the method used to perform the comparison. I will not judge about the tested receivers performance, I will try to point out some wrong statements written about the equipment I made (LNA4ALL).
To quote exactly:
Regarding the LNA tests the Airspy team write:
[In the LNA tests] the LNA [LNA4ALL] might not have enough dynamic range in a high performance setup since it overloads before the Airspy.
This is wrong statement. If we take the R820T datashet figures as the best case scenario the same tuner have the IIP3 at the max gain of (minus) -7.5dBm. The LNA4ALL have the measured (real figures) OIP3 at the max gain (plus) 34dBm. Taking the max gain of 24dB the LNA4ALL IIP3 is then (plus) +10dBm. Of course, the higher number (positive) is better. For the guys that are not familiar with the linearity and IP3 theory, this is the difference like driving the Yugo 55 and Ferrari. It is obvious that the receiver using the R820T tuner will be overloaded before the LNA. Well, the HackRF guys are using the LNA4ALL as the transmitt power amplifier delivering 180mW of output power. This should be clear enough proof of P1dB and what the LNA4ALL can deliver.
The second wrong statement:
The Airspy team suggested that the LNA should improve SNR on the Airspy, but that the LNA we used was not suitable for our environment due to it overloading on BCFM signals. They suggested that we should have used a LNA with a much higher dynamic range such as the PGA103+.
If they ever build and measure the LNA with the PGA103+ they will never write such a statement. But even if they consult the datasheet they would see the the declared higher dynamic range can be achieved just on the higher frequencies, above the frequency range of the R820T tuner (much higher). This myth came from the “copycat” approach where the “designers” are just copying the layout and the declared figures without masuring anything seriously. Most of this LNAs are not even working properly because the builders were so lazy to read the complete documet set like Technical note AN-60-064 regarding the unstability problems. This LNA is not unconditionaly stable below 150MHz thus the Minicircuits release the patch (stabilizing network) at the MMIC input to meet the Rollet factor K over 1. How many PGA103* LNAs have you seen using this patch? Some of the fair designer admits that they have problems with unstability and they did try to solve that problems with the bias coil, but most of the designers does not recognise that problem at all. The MMICs are just smoking after you turn on the desktop light connected to the switched 12V power supply 🙂
On the other side the SDRPlay guys recognised the problem of uing excessive gain (LNA4ALL) in front of the SDRPlay properly. The SDRPlay have already the LNA inside, so extra LNA with such a high gain is not required. The proper test should be comparing the Airspy and SDRPlay without internal LNA but with the external LNA4ALL. I will stop here. If not, I risk to write a really long comment.
Your input is much appreciated Adam, we need more technical feedback in these types of situations.
I do appreciate a long comment of this quality anytime, Adam! Please feel free to blow up the page! 🙂
Hi Adam, please do the long comment if you are willing! I’m always interested in feedback from RF professionals like you. If anything is very wrong in our testing we will retest, or at least add an note in the article pointing out the criticism of our testing. The goal of our tests was to test the SDR’s in a real life setting with several strong signals around, and produce some example screenshots which might be indicative of what you might see with these SDRs in a similar “signal browsing” set up that is common with RTL-SDR users.
Leif has already done some of the hard number tests, although there are criticisms about his tests from SDRplay. It would be interesting if you or Leif could do some more hard number tests with your test equipment. The other hard number tests by other users that i’ve seen haven’t been done properly as far as I can see. For example all SINAD tests I have seen so far by testers with the right equipment did not set the SDR gain and sample rate settings correctly. If you don’t have the units i’m sure each company should be willing to provide you samples since you are well known in the SDR community.
Also, about testing without the internal LNA, in the tests without the LNA we have indeed purposely turned down the LNA gain setting on the Airspy and disabled the Mirics LNA in the RSP to improve linearity. However, the MGA-68563 on the RSP is “always on” and cannot be turned off.
“However, the MGA-68563 on the RSP is “always on” and cannot be turned off.”
Are you sure? Isn’t it that the MGA68536 is just not having a true bypass, but is turned off by removing power via the software?
Yep the MGA68536 is always on for all frequencies above 60Mhz. Check the schematics at http://www.sdrplay.com/docs/SDRplay_RSP_Schematics_r2p3.pdf there is no bypass switch. Also this post with a reply from SDRplay http://www.sdrplay.com/community/viewtopic.php?t=299. They use that LNA to overcome the RF filter losses.
The second LNA which is internal to the mirics chip can be turned off and on in the software.
First, I’m really impressed by the excellent simplification job done by Team RTL-SDR.com. Anyone with a basic setup can reproduce these tests and form his own opinion. The entire article is fluent and a is real reading pleasure.
I tend to ignore random pseudo-technical comments in the Internet, but this one really pushed it too far. Arguing about PGA-103+ not being better than the PSA4-5043+ because it requires an extra coil to just makes any actual RF engineer laugh. The LNA tests clearly show the LNA4ALL started introducing nonlinearities. Since the RF gain was set low on both Airspy and SDR-Play, we cannot speak of saturation in the tested SDR’s. The poor LNA4ALL didn’t improve the NF because it was smacked by the all the VHF/UHF blockers. The only test that have improved things a bit had a FM BC filter *in front* of LNA4ALL. A more robust LNA with better linearity should have smoked the LNA4ALL in all these tests and should have given a better perception of the differences. But I understand it’s supposed to be cheap, so “high performance” was not the target in these tests. Just please… don’t spread BS. You are not doing the concerned population any favor.
> B. von Klaus
Dear “Mr actual RF engineer” please build a few PGA-103+ based amps and operate them over a wide frequency range on a long coax as antenna preamps for a while and you will stop laughing. The extra circuitry mentioned in the much later released application note, which is a necessity in order to get this thing half-way stable is not exactly improving the overall performance.
Adam describes the situation very well and believe me it is not a coincidence that a lot of preamps, e.g. for active ADS-B antennas that need a very low noise figure while having a great dynamic range magically are all being distributed with the same MMIC as the LNA4ALL and not the PGA-103+ which just looks much better on the paper. You can be sure that Adam would use the chip if it would be stable, since it is cheaper than the PSA4-5043+ and as mentioned offers less noise while having more dynamic range.
So maybe before you start laughing and making the LNA4ALL look bad, breath a bit a of real world experience, because these MMICs are very tricky to handle … I have been killing a few though I ran them with a current and voltage limiter set below its max current, which is something I have never experienced with any other chip!
I also run a few PGA-103s successfully for a few years but please don’t ask me why this process seems almost like a lottery game. Anyway I would never be selling these to end users and totally understand why so many designs end up using the PSA4-5043+ … it’s definitely not because they are too dumb to create a proper wideband capable RF environment to operate them in!
I see we both learn the hard way how PGA-103 perform. When the PGA-103 was released I was pleased with the datasheet figures but a bit suspicious about device performing up to 6GHz with the parasitic using the SOT-89 package. But hey, I said let’s not judge the device before we test it. Build the amplifier, everything looking fine until we switch on the desktop lite (running on the switching power supply). Replaced the PGA-103, and again popping as the popcorn after desktop light switched on. Consulting the S2p files and analyzing the device we notice the problem bellow the 150Mhz but nothing that we have not seen on the other mmic devices so far. Contacted Minicircuits to see what I am doing wrong and got reply that they are aware of the problem and they email us patch (stabilization input circle) at that time not published yet in the technical note. Patch applied, seen some improvement but still not unconditionally stable LNA. Of course, the LNA NF and other parameters were degraded approaching the PSA4-5043 figures. I did try to solve the problem, used the bias-T advised from the Minicircuits, layout as proposed but the results were always the same. The current and voltage protection on the lab power supply are just to slow for that transition. I did monitor on the spectrum analyzer the wideband output and using the phase shifter at the input creating all kind of combinations and at certain point the device pop up…. the oscillations were present on the HF region even with the stabilizing network. They were lower then without network but still present.
I decide not to use this device as the users may create all kind of input conditions using wires, long antennas, open, short etc. and this device can not handle all that on such a wide range of frequencies.
Minicircuits have quite strong PGA-103 advertising campaign what can be seen reading the various uW magazines. The technical note regarding the stabilization patch was upgraded several times. Driven by the fact that most of the buyers are probably not reading that papers they now include the patch in the datasheet too, at the very end of PDF file.
Recently we got some equipment fail to work. Inspected and found only PGA-103 burned in the simple LO amplifier chain. All other mmics (other types were OK). Further inspection bring me to conclusion that poor passive mixer isolation between the ports feed the HF IF drive to the PGA-103 attached to the same mixer from the LO side and the PGA-103 was damaged.
The problems are present and this post if far away from BS. They can help others not to run in the same problems.
I agree with Adam. 73!
Thanks for the detailed rewiew. Airspy is the clear winner but i cannot afford to buy a 700$ laptop to run it. SDRplay is a good budget SDR but after this review i am a little disappointed on how it compares to Airspy on VHF-UHF; i expected much more from a 8 filters preselector. The perfect budget SDR has not been released yet. Only those interested mainly to receive HF can be happy to see the best price matching with the best performance.
A $700 computer to run the Airspy really? I didn’t know you needed one of those. I am going to have to tell my $60 Intel Pentium about that and ask him to please stop faking things.
Too much on one page indeed. I don”t get why the HackRF is always getting into comparisons like this as it’s not even pronouncedly marketed as SDR for listening purposes but as a device for RF measurements
I’ll think about splitting the post into 2 or more pages, it might be a bit hard on slower internet connections or PCs.
Originally I wasn’t going to include the HackRF in this review, but again and again I saw forum posts where someone requested a recommendation for something better than an RTL-SDR, and the HackRF kept being suggested alongside the Airspy and RSP, with no mention that the HackRF is intended for a completely different purpose than the Airspy/RSP.
BTW I think putting this on a single page is a bad idea, my browser is totally acting up, the computer freezes and a page reload causes several minutes of elements jumping across the screen while causing more hanging of the whole computer because the browser is pegging the CPU during load. Writing this comment took ages.
If your computer cant handle this webpage then how is going to handle any sdr?
LOL… just spit beer on my SDR.
Okay split into three pages now.
The only thing I don’t like about this review is that it came 3 days AFTER I bought an SDRplay, finding out about the various modes of overloading mayhem all on my own. I’m not even living in a city. A lot of fiddling in the menus is needed to beat it into shape on each band. Besides all theory I found that the LNA is increasing SNR significantly, at least in the 88-140Mhz range (didn’t make test anywhere else yet). Would I have bought one of the other two? No, I think the SDR I really want to buy hasn’t been developed yet.
Excellent write up. Kudos amigo! I’d like to add some contextal opinion to your conclusions:
HackRF is the clear ‘value choice’ for SDR transceivers and is the entry-level gateway to the ‘big world of RF’. Think about it from the viewpoint of someone with limited means just learning about the ‘invisible world’ .. HackRF + tablet (~$600) allows hacking into a $120K Tesla. Designer Michael Ossmann uses this logic when speaking to security & academic crowds saying if we do not put this technology into the hands of the good guys, the bad guys will find it anyway and then we are in deeper trouble. It is indeed a brave new world!
Airspy is the ‘value choice’ of the VHF/UHF SDR bunch. It costs more b/c it uses a tighter crystal oscillator, provides a expansion headers and bias T and uses a higher-requirement USB buss, and does so because this is what is required for serious UHF work. Plus Airspy authors its own software and 3rd-party plug-ins give Airspy the “complete package of impressive UHF performance”. Add to that, only Airspy allows for diversity reception which means synchronization of two receivers which means a higher tier of non-dropout reception.
SDRPlay is the ‘value choice’ for the serious all-band, all-mode hobbyist on a budget. “$150 + a 3rd-hand cpu will get you the world”. It’s the one I bought to go w/ my 10 year old laptop :).
I know it’s a long time since you wrote this, but could you point me in the right direction for information regarding implementing the diversity features of the airspy products? Thanks. You could email me at tasmedic at yandex dot com. Many thanks.
the airspy still have usb noise issue. strong usb noise @ 480MHz,240MHz,120MHz.
Great writeup, will take me a bit of time to tuly digest it all. Thank you for immediately pointing out the significant shortcomings of the HackRF. It may be in the same price range (highest priced of the three), but IMHO the performance of HackRF One is unnaceptably poor. I’m hoping that sales suffer significantly and force the creators to fix the glaring issues in that device. It seems that the kickstarter origin may have caused the creators to rush the design and just release a “functioning” model.
I think you need to look at the history of the HackRF One. There was the 500 government paid for Jawbreaker before it, and before that jellybean, licorice, lollipop, lemondrop and bubblegum revisions of the hardware. I do not think that the Kickstarter caused any rush to market.
I think the HackRF is very good at the job it was designed for – hacking. It was never made to be a good receiver for hams or scanner hobbyists, but rather a tool that does it all for wireless security work, which is usually concerned only with signals in the very near vicinity.
There was some misconception that the HackRF would make a good radio for ham/scanner user which is partially why I wrote the article.
I knew the Airspy was better than the SDRP and HRF1, but nice to see more evidence of it.
I got rid of my Spyverter because of the need to use a switch with the Airspy. Sold my HackRF1 with just a couple hours on it, really not a good receiver.
Now I have the SDRP, the Airspy (no Spyverter), RTLSDR dongles of course, and a “real” SDR that hasn’t been reviewed here yet. 🙂
Many many thanks for the article and all your work RTLSDRblog!
vy 73 f
The only downside to buying the Airspy is the bucket load of attitude you get free from the developer.
True True True
Apparantly he is entitled to some attitude with such a good product.
What have you developed for us lately?
It is an awesome product. It is also entirely possible to produce an awesome product and not have the attitude. One does not require the other, and says more about the person wielding the attitude than the product.
Thanks for this rather extensive review/comparison, it provided a ton of useful info without going bonkers on the extremely technical side of things (not that that type of review info isn’t useful, mind you) and will most definitely end up helping a lot of people make their purchasing choices as to what SDR hardware might suit them best.
Have fun, always…