Category: SDRplay

A Review of the SDRplay RSP2 by DB Gain

Over on the Utility DXers file section at, Mr. D.B. Gain has uploaded his latest review of the SDRplay RSP2 (pdf). The SDRplay RSP2 is the successor to the RSP1, and is a 12-bit SDR with tuning range from 10 kHz – 2 GHz. It currently costs $169.95 USD.

DB Gain’s review first covers the features of the RSP2, and some basic SDR vs Analogue theory. He talks a bit about what criteria makes a good SDR and discusses why SDRs are so good for digital work. The review then goes on to talk about the SDRuno software, sensitivity settings, and voice mode work. The review mostly concerns the RSP2’s use on HF, and in this respect DB Gain appears appears to be extremely impressed with the results that the RSP2 gives him.

Previously DB Gain has also reviewed our RTL-SDR V3 dongle (pdf).

The first page of DB Gain's SDRplay RSP2 Review
The first page of DB Gain’s SDRplay RSP2 Review

Setting up Propagation Triggered Spectrum Recording

Over on the SDRplay blog and forums OH2BUA has been sharing how he has set up ‘propagation triggered recording’ by continuously monitoring JT65/JT9 signals with his SDRplay. The idea is that you leave the radio on receiving all night, and set it to automatically start recording IQ files if good propagation conditions occur as determined by the locations received from the JT65/JT9 signal. This may yield some interesting far off stations that can be listened to in the morning, whilst weeding out hours where nothing but commonplace local stations are heard. The software is a simple Windows batch file that works together to coordinate HDSDR and JTDX. It should work with any HF capable SDR.

JT65/JT9 are weak signal propagation HF modes (also known as WSJT modes) that can be decoded all around the world, even with very weak reception thanks to strong digital error correction. They can often be used to determine propagation conditions by determining where successfully decoded messages are being sent from.

OH2BUA writes:

I have made a set of scripts and other files which can be used to build a system which monitors JT65/JT9 (digital modes) amateur radio traffic on 160m/1.8MHz band, and if nice propagation to area you are interested in exists, a MW-BC-band recording is started. When the conditions fall off, the recording is stopped.

There is an attached zip-file containing all the necessary stuff. Sorry this is a windows thing – but easily portable also for linux. Create C:\bat\ and drop all there. Have a look, starting from README.

The default example is to start a MW-band I/Q-recording, if North American ham signals are heard – but it is fully modifiable according to your target when in comes to areas, bands, schedules etc.

The files are available as an attachment to the forum post.

Where WSJT Modes are located (
Where WSJT Modes are located (

Comparing the RSP1 and RSP2 on MF Non-Directional Beacon Reception

Over on our new YouTube channel we’ve uploaded a video comparing the SDRplay RSP1 and RSP2 on reception of Non-Directional Beacons at around 350 kHz. Both radios had their gains adjusted for the best possible SNR and reception. They were connected through a splitter to a Wellbrook Magnetic Loop antenna. The Hi-Z port on the RSP2 was used as Port A and Port B don’t have good reception below about 1 MHz.

In all tests the RSP2 appears to have the better SNR, a lower noise floor and thus better audio, though from the spectrum view the RSP1 seems to have a little less spurs.

Subscribe and keep an eye on our new YouTube channel as soon we’ll be uploading more RSP1 vs RSP2 comparisons, Airspy vs RSP2 comparisons and other SDR related videos as well.

SDR-Console V3 Preview Updated to Support the SDRplay RSP2

Recently Jon from the SDRplay team wrote in to let us know that SDR-Console V3 (preview version) has just been updated and it now supports the RSP2. The RSP2 is the successor to the popular RSP1 software defined radio. It has improved filtering, more input ports, improved LNA, and just overall improved performance. See our initial RSP2 review here. They write:

Many thanks to Simon Brown for updating SDR-Console V3 Preview to fully support both the RSP1 and the RSP2- you can download the software from (be sure to click on the software link under where it says ‘Downloads’ unless you want to download the software from the advertisers who support Simon’s work!)

As new YouTube demo videos of SDR-Console V3 in action become available, we will add them to the playlists on our YouTube Channel:

The RSP2 now supports its native SDRUno software, HDSDR through an extIO module, CubicSDR and now SDR-Console V3.

The RSP2
The RSP2

Cloud-SDR Releases New Client and Server Software for the RTL-SDR

Cloud-SDR is a company that aims to make using SDR over the cloud/network/internet easier. It allows you to set up a remote SDR server that you can access from anywhere. Previously Cloud-SDR was still in development, but now we recently received mail from Cloud-SDR programmer Sylvain that the client and server software has just been released for the RTL-SDR. It appears that it also currently supports the Airspy, BladeRF, SDRplay and PerseusSDR.

The email reads:

I am pleased to inform you that we have just released two softwares compatible with your devices :

  • The Cloud-SDR free client, a windows + Linux (to be released soon) client able to run locally RTL-SDR devices (check the news/turorials, we have featured several times dongles from your blog)
  • The Cloud-SDR streaming server (codenamed SDRNode) , a windows + Linux (to be released soon) multi-user configurable streaming server.

SDRNode is a commercial software but an evaluation version is already available. Both softwares can be downloaded from our store after registration.

Source code for the drivers are already released as open source software through our GitHub repo:

You can find more details here :

The Cloud-SDR Network
The Cloud-SDR Network

To download the software you must register an account with them at The client is free but the server costs 110 euros for personal and hobby usage, although a 30 day trial version is available. Currently only the Windows Client and Server are available, but they write that Linux should be available soon.

We tested the software out with an RTL-SDR V3. The client installation process was a simple wizard and after installation we launched the Cloud-SDR client by opening the shortcut “cSDRc” in the Start Menu. We found that the hardware needed to be plugged in first for the client to recognize it. The client is basic, but can already demodulate USB/LSB/CW/AM/FMN without trouble. It also has some interesting features:

  1. Dual channel receiver: RXA and RXB are two totally independent receivers;
  2. Geographic integration: Display on map beacons, ADS-B reported airliners, known HF broadcast stations or any geo-localized information coming from the SDRNode server;
  3. GPS compatibility: plug a GPS receiver to your computer and track your location on the map, record signals with your position for later processing (coverage mapping etc.); display the UTC time;
  4. Digital Terrain Elevation: See the terrain elevation around your position, or in the direction of the antenna directly on the map (requires to download the free SRTM3 files from NASA, with 90m resolution);
  5. MP3 audio recording: record to mp3 the demodulated streams to reduce disk requirements;
  6. Chat with other users connected to the SDRNode Group: when used as a remote client for the SDRNode streaming server, you can interact with other users with messages or station spotting;
  7. Time-domain analysis: the MSR mode enables analysis of any sub-band and displays in real time the time domain signals of the selected spectrum portion. This sub-band can also be recorded (with geographic position if GPS is connected) and processed with provided MATLAB®.
The Cloud-SDR Client Software
The Cloud-SDR Client Software

Next we tested the evaluation version of the SDR-Node server software on a remote laptop with an RTL-SDR connected. Again installation was easy, just follow the wizard after ordering the evaluation version. SDR-Node installs itself as a Windows service which starts up automatically on boot. To set up the Node we followed the guide shown in the video below. To connect with the client you need to know the IP address of the remote computer, the port is 8080, and the certificate is displayed on the server PC SDR-Node dashboard. We note that we also had to disable the Windows firewall to get it to connect, but it should be possible to also add SDR-Node to the firewall whitelist.

When streaming it appears that only 1/4 of the SDR sample rate can only be sent over the network. There are also compression options which can be used on slower networks or the internet to reduce bandwidth. Using the interface while in network mode was slightly laggy, but the waterfall and audio was smooth.

Overall everything worked as expected and it looks to be a very useful tool. More information is available at Some already existing alternative remote SDR streaming software that supports the RTL-SDR includes rtl_tcp, the SDR Console V2 server, OpenWebRX and ShinySDR.

Comparing the RSP1 and RSP2 on VLF, LF and AM BC Reception

Over on YouTube user Mile Kokotov has uploaded two new videos that show both the SDRplay RSP1 and RSP2 receiving VLF, LF and AM BC signals. The SDRplay RSP1 is a 12-bit SDR that can receive from about 10 kHz – 2 GHz. Recently the RSP2 was released which is an upgrade over the RSP1 with additional filters and features. On this blog we did an initial review of the RSP2 and found mostly improved performance over the RSP1.

Mile writes about the signals he receives:

Antenna on RSP2 is connected to its Hi-Z port.

Here are some information about signals in this video:

60 kHz Time signal from NPL is a radio signal broadcast from the Anthorn Radio Station near Anthorn, UK.
The signal, also known as the MSF signal is broadcast at a highly accurate frequency of 60 kHz and can be received throughout the UK, and in much of northern and western Europe. (But I am receiving it in Macedonia) The signal’s carrier frequency is maintained at 60 kHz controlled by caesium atomic clocks at the radio station.

77.5 kHz Time signal is German DCF77 longwave time signal and standard-frequency radio station. The highly accurate 77.5 kHz carrier signal is generated from local atomic clocks that are linked with the German master clocks.

On 295 kHz there is NDB (Non directional Beacon) from Alexander The Great Airport near Skopje (about 80 km from my home)

On AM Broadcast Band (530 kHz – 1620 kHz) you can see how many AM stations are on the spectrum display (with 9 kHz raster) receiving here at my home with Mini-Whip antenna which is only 10 cm long!

More information you can find on my web-page:

The first video shows reception with a Mini-Whip, and the second with a Delta Loop. We don’t see much difference in reception between the RSP1 and RSP2 in these videos but viewers with more sensitive ears may be able to tell us if they notice any differences.

Some More Reviews of the SDRplay RSP2

Two days ago the RSP2 was released for sale as we released a review of a pre-production unit that they sent us. Since then there have been some more review that have come out from other users who had a review unit. have released a good review of the RSP2 along with a video. The author writes how he’s impressed with the additional shielding, the software switchable antennas and the bias tee. Like in our review he also tested the RSP2 bias tee with the Outernet LNA and found good results. He notes that the RSP1 and RSP2 are very similar in terms of RF performance, but writes that he noticed times when the RSP2 seemed to be more sensitive or exhibit a lower noise floor than the RSP1.

On YouTube user reviews the RSP2 and also has a live Skype interview with Jon the head of marketing at SDRplay. Jon gives a good overview of the new features and some applications that they could be used for.

Over on Paul Jones also reviewed his RSP2. He was very impressed with the performance of the Hi-Z port, the performance of the BCFM notch filters and the stability of the TCXO.

The author of has also released his review and he too was impressed by the improvements.

On a related note the RSP1 is now for sale for black friday at HamRadioOutlet for only $119.95 USD.

SDRPlay RSP2 Release Announcement and Review

Today SDRplay have just released their newest software defined radio – the Radio Spectrum Processor 2 (RSP2) which is the successor of the RSP1. The RSP2 costs $169.95 USD, and the older RSP1 is still for sale at $129.95 USD. There is also the “RSP2pro” model which is an RSP2 in a metal enclosure, and this sells for $192.95 USD.

The RSP2 has nearly the same base specifications as the RSP1 (12 bit ADC, 10 MHz bandwidth, 10 kHz – 2 GHz range), but now comes with additional features and enhancements such as a software switchable BCFM and BCAM notch filter, TCXO, multiple antenna ports, HF optimized Hi-Z antenna port, clock in and out ports, better shielding and can also now tune down to 1 kHz.

It is available for purchase at (Worldwide), (USA) and ML&S (UK).

The announcement reads:

SDRplay Limited has today announced the launch of a second Software Defined Radio product – the RSP2.

Building on the popularity of our first product, the RSP1, we have now launched the RSP2. The RSP2 delivers a significant number of additional features which result in a higher spec for specialist amateur radio users as well as benefits for additional scientific, educational and industrial SDR applications.

Here are the main additional features of the RSP2:

  • 10 built in front-end pre-selection filters, with substantially enhanced selectivity
  • Frequency coverage extended down to 1 KHz
  • Software selectable variable gain Low Noise Preamplifier
  • 2 x SMA Software Selectable 50Ω RF ports (1.5 MHz – 2 GHz)
  • 1 x High Impedance RF port (1 kHz – 30 MHz)
  • Built in software selectable MW /FM notch filters
  • Highly stable 0.5PPM TCXO trimmable to 0.01PPM
  • 24MHz Reference clock input / output connections
  • 4.7V Bias-T option (on one of the software selectable antenna inputs)
  • RF screening within a strong plastic case for the standard RSP2
  • A Rugged metal box version – the ‘RSP2pro’

When used together SDRplay’s own SDRuno software, the RSP2 becomes a high performance SDR platform. The benefits of using the RSP2 with SDRuno include:

  • Highly integrated native support for the RSP2 professional grade software based upon class leading ‘Studio 1’, free of charge
  • Calibrated S-Meter including support for IARU S-Meter Standard
  • Calibrated RF Power Meter with in excess of 100 dB of usable range
  • Best in class audio quality

Currently the RSP2 requires the use of SDRuno software, but in the coming weeks we plan to provide support for HDSDR, Gnu Radio, CubicSDR and we are working with Simon Brown to get support within SDR Console.

We believe that the RSP1 will continue to prove very popular as the lowest cost 12-bit SDR for general applications such as Short Wave Listening or for use as a panadapter and we pleased that we can now offer more choice to the growing community of RSP users.

The RSP2 is expected to retail at approximately £130 (excluding taxes) or $169 (excluding taxes)

For more information visit our website on

The new RSP2
The new RSP2

The table below shows a comparison of the RSP1, RSP2 and RSP2pro. A datasheet can be found on SDRplay’s new RSP2 webpage.

Differences between the RSP1, RSP2 and RSP2pro.
Differences between the RSP1, RSP2 and RSP2pro.

SDRplay RSP2 Review

Two other reviews have already come out, one from and one from

Thanks to the generosity of the SDRplay team we were fortunate enough to receive an early pre-production review model of the standard (not pro) RSP2 unit. The unit arrived a few days ago, and here we give it an initial review. In a previous review we did a comparison of the Airspy SDR, SDRplay RSP1 and HackRF. We found that the RSP1 and Airspy had similar overall performance, but that the Airspy would be better for those people who needed high dynamic range performance in strong signal environments, and that the SDRplay RSP1 would be best for people who wanted a low cost all-in-one unit with performance better than an RTL-SDR. 

The Inside

We decided to take a look inside and see how much the PCB has changed from the RSP1 to the RSP2. Judging from the two photos we can see that there is quite a significant increase in the number of components used. What was once a sparse PCB is now populated much more heavily with additional filter banks and several new switches. However, the core design of the RSP2 remains similar to the RSP1. The RSP2 uses the same Mirics MSi001 tuner chip and MSi2500 ADC chips.

The standard plastic enclosure is also now spray painted on the inside with conductive metal paint which helps by acting as a Faraday cage. This prevents interference from getting through and should be almost as good as a metal enclosure.

The conductive paint seems to be working well, as in our tests the RSP2 does not receive any signals with the antenna disconnected, whereas the RSP1 does weakly receive some very strong pager signals.

Conductive paint on the plastic case inside.
Conductive paint on the plastic case inside.

Continue reading for the rest of our review

Continue reading