Category: News

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.

Airspy Competition Winners Announced

Last week the Airpsy team gave us the opportunity to give away some prizes, so we started a comment competition. The prizes were an Airspy R2 + SpyVerter, Airspy Mini + SpyVerter and SpyVerter. The competition closed yesterday with over 500 entries, and the winners have now been selected via Congratulations to the winners below:

Larry (Airspy R2 + SV)
If I am going to win something from this one stuff, me build internet remote receiver on hill in central Europe (CZ) for all readers and fans of website, generally for all RTL SDR enthusiasts….. :-)))
Pour Felicitér 2017
Larry (Ladislav)

kevin (Airspy Mini + SV)
been a ham a couple years now. their are so many uses for sdr’s ! it’s so cool. just looking down the list of others comments, i was like ‘oh ya’ forgot about that idea. awhile back we did a demo at our ham club with a el cheapo sdr and it sparked some interest , would like to play around with some of the newest toys, worlds of diff in capabilities. ultimate goal is to find the right one for the clubs emergency trailer. seeing the bands and whats going on, is priceless :)

Josh (SpyVerter)
I’d love to finally get into the HF band!

If you’re a winner please check your email address for the competition winner email.

The competition produced some very interesting comments that show the diversity in projects that can be performed with a SDR receiver and we strongly encourage you to read through the comments if you are looking for project ideas.

If you didn’t win, sorry! Better luck next time. But please continue to follow us on Facebook and Twitter as we will have more competitions and more prizes to give away later in 2017!

HDSDR Version 2.75 (Stable) Released

The beta 2.75 version of HDSDR was released about two months ago. Now the stable version has just been released. HDSDR is a free general purpose SDR receiver, similar in nature to other programs like SDR# and SDR-Console. HDSDR can be downloaded from

The author of HDSDR emailed us with the following release information:

this morning we released the final version 2.75. Here’s the changelog:

Version 2.75 (January 01, 2017)
– more recording options
– support for 8bit sampling format – ideal for RTLSDR, halving RF recording size
– display level / clipping for RF and AF
– additive noise generator for hiding aliases
– Highpass Filter for AM/FM deactivatable – useful for slow digimodes
– configurable gain for I/Q output – useful for digimode decoding weak signals of SDRs with >16 Bit dynamic range
– Uniform “Calibration” dialog for Frequency/S-Meter/DC Removal/Channel Skew
– “Custom color palette” to customize colors of Waterfall/Spectrum and some more
– output soundcard no longer necessary (e.g. for recording or monitoring)
– support for 8k display resolution (7680×4320)
– some new keyboard shortcuts (see )
– extended ExtIO capabilities
– experimental transmit capability through ExtIO API interface
– many fixes and improvements

Some of the new features were introduced especially for the RTLSDR Dongles:

– 8 bit support, of course

– displaying the RF (ADC) level in dBFS allow working with deactivated Tuner AGC – NOT oversteering/clipping the ADC.
This would also ease making good suitable recordings as used in

Especially for decoding this kind of signals (AM/FM) , deactivating the Highpass filter (Ctrl-H) will make the demodulated Audio clearer:
long periods of positive or negative levels will not fade towards zero.
Find attached recordings and screenshots with active and deactivated highpass filter of a garage door opener demodulated in AM.

– additive noise generator (Ctrl-N) is for hiding some alias carriers in scenarios where the ADC does not see real noise from the antenna.
The noise generators level has to be configured carefully for not hiding real signals. A level between -25 to -10 looked fine for me. But that should be measured in a lab.

Below are the mentioned attached images and .wav files.

Highpass Filter - Active
Highpass Filter – Active
Highpass Filter - Inactive
Highpass Filter – Inactive

Highpass Active .wav file (Download)

Highpass Inactive .wav file (Download)

Airspy Mini Christmas Sale – $80 USD

The Airspy Mini is a software defined radio with a tuning range of 24 MHz to 1800 MHz, 12-bit ADC and up to 6 MHz of bandwidth. It usually costs $99 USD and is the younger brother of the $149 USD Airspy R2.

Currently the manufacturer iTead is running a Christmas sale on the Airspy Mini. The sale price is $80 USD, which is a 19% saving. To get the sale price you need to click on the “Get coupon code here” link and then share the promotion to your Facebook, Twitter or LinkedIn account.

Update: They have given us a special blog coupon code “AS-RTLSDR-BLOG“. Just use this code at the checkout and it will apply the discount without the need to share. Edit: The blog coupon appears to have stopped working, an alternative one that is still working is “as3“.

The sale lasts from December 20, 2016 – January 3, 2017.

If you want to see more about the Airspy Mini then see our review here. Our other previous review comparing the Airspy R2 against the SDRplay RSP and HackRF may also be of interest as the Mini’s performance is very similar to the R2.

The Airspy Mini iTead Christmas Sale
The Airspy Mini iTead Christmas Sale

New Linux RTL-SDR Driver with Fully Exposed Controls

A new Linux based driver for the RTL-SDR has been released by Milen Rangelov (aka gat3way) which exposes all the adjustable settings on the R820T/2 tuner chips. This exposes adjustable sliders for settings like preselection, IF and notch filters and the multiple gain stages on the R820T/2. In the standard drivers the filters and gain settings are mostly set automatically, but manually adjusting them could yield better results. The filters are not very strong, but they could be used to help block out an interfering signal, increasing the dynamic range of the RTL-SDR.

Over on his post at r/rtlsdr Milen wrote the following about his driver:

The idea in brief is to modify the librtlsdr code so that an unix domain socket server receives i2c register set/get commands and executes them. It only works for r820t tuners. This modified rtlsdr library is then dynamically preloaded by means of LD_PRELOAD and used by the SDR software. This is actually what happens when you call r820tweak <program>. This way, no modifications to both gr-osmosdr source and the SDR program are required, instead of waiting for them to implement those controls, we kind of have a separate program that tweaks them.

The GUI program is a simple wxpython client, it currently exposes the following settings:

LNA, Mixer, VGA gain stages – the 3 variable gain stages

LPF/HPF filter cutoff – these control the “width” of the r820t2 lowpass/highpass filters, those filters are relatively sharp and this in turn is very useful to increase the dynamic range by fitlering out strong signals “close” to the weak signal you are hunting. Those are among the nicest features to play with, together with the gain stages.

LPNF cutoff – apparently there is also a low pass notch filter, however this doesn’t work as I expected. Anyway, still useful as a kind of variable attenuator.

Filter bandwidth – there is a bandpass filter which isn’t quite “sharp” at all, centered at the center frequency. Kind of additional filter, easier to manipulate than the rest of them, but not that powerful. May provide some extra dynamic range. Behaves kind of weird when gqrx decimation is used.

As far as the gain stages are concerned – the LNA gain is the first stage and thus the most important – it determines the SNR. Mixer gain is less important (unless the signal is too weak). The VGA gain should be almost always set to zero as it doesn’t contribute to the SNR at all while keeping the dongle warmer and so more thermal noise.

In the R820T2 i2c register specs there are some other interesting features, currently unexposed. One of them is the band selection filter (lo/med/high) which apparently is even used in the librtlsdr driver. I found changing that has absolutely no effect for me unfortunately. It might have provided opportunities for better reception around the “verge” where the librtlsdr driver switches them (approx. at 310MHz and 588MHz). But switching them has absolutely no effect.

The new fully adjustable driver by gat3way.
The new fully adjustable driver by gat3way running in GQRX. V3 Stock Availability and Holiday Shipping Times

This is just an update post for those wishing to purchase or are waiting on delivery for items from our store at

Amazon USA

The V3 has proven to be more popular than we anticipated and Amazon ran out of stock a few weeks ago. New stock should be arriving at the Amazon warehouses early next week, but we don’t know how long Amazon will take to process the stock and put it back on the shelves. It should hopefully be ready in under a week.


For international orders from our Chinese warehouse, please be aware that international shipping is quite slow at the moment, due to the peak season parcel rush. The international mail system struggles to cope with mail at this time of the year due to a vast increase in Christmas parcel volume. Delivery times are still typically under 4 weeks but for some parcels, and to some countries we can expect shipping times of up to 6 weeks or longer. 

Some people have noted that parcels ordered after a previous order have arrived earlier. We use the same postal system as everyone else (there’s only really one international air mail system!), but what can happen is that on some days the parcels may get a direct flight, and on other days they may get an indirect flight. Those indirect ones can end up taking much longer. Also planes can break down, parcels can miss a connecting flight or security can hold a container of many parcels for days just because they saw one suspicious parcel inside. Thus international parcel delivery times have a very large scattering, ranging from less than a week to six weeks or more. We thank you for your patience if your parcel happens to end up on the slower end of the scale. But if your parcel does end up taking over 6 weeks please let us know as we may be able to open a lost parcel investigation. If your parcel is lost it will be resent or refunded on your preference.

If you are tracking a parcel we recommend, and Try all three as sometimes one has more up to date tracking than another. Please note that we’ve found that around this time postal workers will often not bother to scan the tracking label on parcels, since they are rushing so much. This can cause a lack of tracking updates for a while. Also if there are queues for customs checks in your local country the parcel can wait around in the container without a scan for a long time, until customs gets to it.

We have several shipping methods available. China Post/Swiss Post/HK Post are about the same speed once they leave. But generally Swiss/HK post are faster to leave China. China Post parcels can sometimes take a few extra days to pass through security. Some countries which support it, will automatically be upgraded to EMS ePacket priority mail. We also have some new special methods for some countries which are still air mail, but use a faster more direct flight to the destination. Of course the more expensive express mail services like DHL/UPS/Aramex are also available, but even they have about a 1 week shipping delay at the moment.

However, despite these shipping time uncertainties, the majority of parcels still seem to be making it through the postal system in a timely manner. Thanks to everyone for supporting the blog!

R820T2 Register Description Data Sheet Now Available

Recently Luigi Tarenga wanted to do some work on developing RTL-SDR drivers, so he emailed Rafael Micro requesting some additional documentation about the chip. Usually previous requests to Rafael Micro for such information seem to have gone unanswered, but this time it seems they have decided to publicly released the Register description document for the R820T2 chip.

Previously the R820T datasheet was leaked/released to the public, but the information in the datasheet did not help much with driver development. This register description document describes the function and configuration bits for the registers on the chip, and may be useful for people wanting to develop better drivers for the RTL-SDR.

We have uploaded a copy on our server here.

Description of some of the registers in the R820T2 chip.
Description of some of the registers in the R820T2 chip.