Category: SDRplay

rsp_tcp: An rtl_tcp compatible IQ Server for SDRplay SDRs

The SDRplay team have released an updated version of a program called "rsp_tcp" (originally written by F4FHH Nicholas). This is a streaming IQ server for SDRplay devices, which is directly ported from the original rtl_tcp code that was designed for RTL-SDRs. The rsp_tcp code is fully compatible with the rtl_tcp protocol, so this should allow almost any software that accepts an rtl_tcp stream as an input to use an SDRplay device as the SDR hardware instead of an RTL-SDR.

The downside to using this server is that in order to be compatible with the standard rtl_tcp protocol, the software will downgrade the RSP data stream from 14-bits to 8-bits only, thus forfeiting the RSP's greater dynamic range. However, if a custom ExtIO plugin is used on the client software, then the full 14-bits can be restored.

On their forums the SDRplay team write:

This software is based on a fork of F4FHH’s version of RTL TCP Server. It has been updated to support the RSP features, but also contains an extended mode. The extended mode allows the client (via a compatible interface) to fully control all aspects of the RSPs, including notch filters, Bias-T enable and switching ports (where applicable)

The user guide for the server software can be found on our downloads page and also here: ... _Guide.pdf

We have provided binaries for Windows, Mac and RPi on our downloads page and the source code for all platforms can be found on our GitHub repository:

To utilise the extended mode, extra commands need to be sent from the client. We have provided an example of this in the form of an ExtIO plugin. You can find the Windows dll on our downloads page and the source code for the plugin on our GitHub repository:

In standard mode, the server will be compatible with any RTL server client.

The team also note that they have updated their Raspberry Pi SD card to include the server.

XRIT Decoder Updated: Improved Image Quality and IR Enhancements

USA-Satcom is the programmer of XRIT Decoder, which is a popular (paid) Windows decoding application for GOES weather satellites. With a WiFi grid dish antenna, LNA and SDRplay, Airspy or even an RTL-SDR, high resolution full disk images of the earth can be downloaded from these geosynchronous satellites. Browse through our previous GOES posts for ideas and various tutorials about setting up a receiver.

Recently, XRIT decoder has been updated and now has improved image quality and an antenna alignment helper tool. A further update also adds improved processing for IR images. Over on the SDRplay forums RSP2user has been testing the updates and writes:

USA- Satcom has just released version 1.4.6985 of the XRIT Decoder software package. New features include:

1) Improved image clarity.

2) An antenna Align Mode feature.
3) And a Viterbi and Eb/No (Energy per Bit to Noise Power Spectral Density Ratio akanormalized SNR) graph over time feature. 

The improved image clarity reduces image artifacts at the Earth-space boundary of the image and improves the overall aesthetics of the colorization of the full disk images. The images are quite amazing. The resolution is far better than what can be shown here due to image size limitations for this site. Below is a full disk GOES 16 image from February 17, 2019 and a corresponding zoomed in portion to get an idea of the resolution and clarity (the actual full disk images are approximately 40MB PNG images each which are much greater resolution than the below image)

The antenna Align Mode is a great new feature that allows users to view the Signal Quality, Viterbi FEC, and Eb/No from a distance using large numeric values. This mode enables users to better view these values when fine tuning adjustments to GOES receiving antennas. The Eb/No and Viterbi graphing enables users to see how well their receiving system is doing throughout the day (e.g., over temperature and while the sun is in alignment with the receiving path).

GOES 16 Received by RSP2User
GOES 16 Received by RSP2User

More updates from USA-Satcom to the XRIT Decoder software with a new patch from today. The XRIT file manager now provides IR image enhancements for GOES Bands 8 and 13. Here are some examples:

G16 CH13 & G16 Band8 Enhancements . Images received by RSP2user.
G16 CH13 & G16 Band8 Enhancements . Images received by RSP2user.

See the post on the SDRplay forums for further details, higher res images and the full update history.

Video Showing How to Decode Meteor M2 with an SDRPlay in Windows

Thanks to "Lolo sdr" for submitting his videos that show his process for receiving and decoding Meteor M2 weather satellite images in Windows with an SDRplay and SDR-Console V3. Since the SDRplay is not supported by SDR#, it is not possible to use Vasilli's excellent Meteor Demodulator plugin (site in Russian, please use the Google Translate option) which is only available for SDR#.

Lolo's method gets around this limitation by initially recording an IQ file of the satellite pass in SDR-Console V3, then opening that IQ file in SDR# via the Fileplayer plugin, which is also by Vasilli and available here. The process is a bit of extra work, and the image isn't live, but the image comes out clearly in the end.

The videos are shown below, and subtitles are available in English, French and Italian via the YouTube player options.

Recibir y decodificar Satélite Meteor M2 con SDRplay, parte 1 de 2, grabar el pase, con subtitulos.

Recibir y decodificar Satélite Meteor M2 con SDRplay, parte 2 de 2, decodificar imagen y corrección.

World Radio TV Handbook (WRTH) Reviews the SDRplay RSPDuo

A couple of days ago we ran a post noting that the Airspy HF+ WRTH review was now available for public viewing. Now thanks to Jon Hudson of SDRplay for letting us know that the SDRplay RSPDuo review from WRTH has also been released for public viewing (pdf). The SDRplay RSP Duo is a 14-bit dual tuner software defined radio that is capable of tuning between 1 kHz - 2 GHz, with two separate 2 MHz bandwidths tuned to anywhere within that frequency range.

The review provides an overview of the RSPduo noting it's various features and discussing the SDRuno software. They also note that diversity reception would be an excellent application for a dual tuner SDR, but SDRuno does not support this feature as of yet. In their tests they also mention how they found very few overloading problems.

Jon would also like to note that the pricing in the review is incorrect. The RSPduo is US$279.95, and right now there is a seasonal $50 discount for US customers at HRO.

SDRplay RSPDuo
SDRplay RSPDuo

Black Friday SDR Sales: Airspy 15% Off, SDrplay RSP2 $20 Off, HackRF 20% Off


Airspy is currently running a 15% Black Friday sale over on the manufacturers website, and on their US distributor The coupon code is BF2018.

This results in an Airspy Mini costing only $84.15, an Airspy HF+ costing $169.15, an Airspy R2 costing $143.65 and a SpyVerter costing $41.65. This is the cheapest we've seen these products to date.  


Over on Ham Radio Outlet, the RSP2 is currently reduced by $20, taking it down to a price of only $149.95. The RSP2 Pro is also reduced down to $192.95. Other SDRplay products, and products on their website appear to be not discounted.


Over on SparkFun the original HackRF is 20% off, resulting in a price of only $239.96. It's still double the price of an Aliexpress clone, but it is an original unit. In the UK ML&S are also selling it for 15% off at £219.95. This is the cheapest price we've seen an original HackRF sold for.

Elad FDM S2

At the higher end of the SDR spectrum, we see that the Elad FDM-S2 is currently reduced by $51, resulting in a sale price of $529.

Most of these sales are expected to run until Monday, or until stocks run out.

Have you found any other great SDR deals? Let us know in the comments.

Reviews and Assembly Videos of our SDRplay RSP1A Metal Enclosure Upgrade Set

Over on YouTube we've seen several reviews and installation videos of our SDRplay RSP1A metal enclosure + portable antenna set that we released for sale back in July of this year. The set comes with a metal enclosure, carry case, and a bonus 7m portable wire antenna spool and telescopic antenna. It costs US$29.95 including shipping and is available on our store or via Amazon.

The first review is by Tysonpower. His review is in German, but English subtitles are available on YouTube. In the review he notes that interference appears to be reduced with the metal case, and notes that the SDR is better protected against bumps.

[EN subs] RSP1A Metallgehäuse - ShortReview

We've also seen a review by Danny Shortwave And Radio DX which also shows the assembly process and shows how easy it is to transfer the PCB from the plastic case to the metal case.

Metal Case Upgrade for SDRPlay RSP1 and RSP1A from Amazon

Finally the third video by Koptervision also shows an unboxing, review and assembly timelapse.

SDRPlay Metal Case Upgrade - Unboxing and Assembly

Receiving GOES Weather Satellite HRIT with an SDRplay and 2.4 GHz WiFi Grid Antenna

Over on the SDRplay forums member RSP2user has posted a new tutorial, this time showing how to receive weather satellite images from GOES satellites with an RSP2 and cheap 2.4 GHz WiFi grid antenna

GOES 15/16/17 are geosynchronous weather satellites that beam back high resolution weather  images and data. In particular they send beautiful high resolution 'full disk' images which show one side of the entire earth. As the satellites are in geosynchronous orbit, they are quite a bit further away from the earth. So compared to the more easily receivable low earth orbit satellites such as the NOAA APT and Meteor M2 LRPT satellites, a dish antenna, good LNA and possibly a filter is required to receive them. However fortunately, as they are in a geosynchronous orbit, the satellite is in the same position in the sky all the time, so no tracking hardware is required.

In the tutorial RSP2user notes that he's been using a $16 2.4 GHz WiFi grid dish antenna and the NooElec SAWbird LNA. In the past we've also seen GOES reception from Pieter Noordhuis who used a 1.9 GHz grid antenna from L-Com which seems to be a better match to the 1.7 GHz GOES frequency. However, 2.4 GHz WiFi grid antennas are much more common and therefore much cheaper. In the past there has been debate on whether or not these cheaper WiFi antennas would be good enough for GOES, so it's good to see that the cheaper option is confirmed to work, at least for the satellite elevations found in the RSP2user's part of the USA.

The SAWBird is a 1.7 GHz LNA which is required to improve SNR by reducing system noise figure, and to filter any interfering out of band signals. The SAWbird is currently not available for public sale, but NooElec have noted that it is due to be released soon. RSP2user also notes that the polarization of the dish is important, so the dish may need to be rotated, and also that flipping the secondary reflector significantly increases the gain at 1.69 GHz.

For software the XRIT demodulator from USA-Satcom for a small fee is used together with the SDRplay RSP2. As seen by Pieter Noordhuis' results, it's also possible to receive these signals with an RTL-SDR and Pieters free software. So it may be possible to reduce the costs of a GOES reception system by using an RTL-SDR, SAWBird and 2.4 GHZ WiFi grid antenna. With those components the total cost would be well under $100.

As a bonus, in later posts on his forum thread, RSP2user shows that the system can also be used to receive HRPT images from the low earth orbit NOAA 19 satellite by hand tracking the antenna as the satellite passes over.

RSP2users GOES Receiver: SDRplay, SAWBird LNA, 2.4 GHz WiFi Grid Antenna
RSP2users GOES Receiver: SDRplay, SAWBird LNA, 2.4 GHz WiFi Grid Antenna

RadCom Review of the RSPduo Now Available Online

In the July 2018 edition of the UK based amateur radio magazine 'RadCom' Mike Richards wrote up a review of the RSPduo. This review is now available for free to download from SDRplay (pdf). The RSPduo is the latest product from SDRplay. Unlike previous models the RSPduo has two tuners on board which can be used to tune to two independent 2 MHz wide areas of the spectrum simultaneously. It currently retails for US $279.95 + shipping.

Mike's review goes over the design of the RSPduo and discusses it's dual tuning capabilities. He mentions that the most exciting prospect of the RSPduo is going to be the phase-coherent applications, such as active noise cancelling. At the moment no software for these applications is available, however SDRplay is working on it. In addition to this, Mike also discusses the new API, changes to the filtering and connections, and well as some notes on sample rates and decimation.

Inside the RSPduo
Inside the RSPduo