SDR4Everyone: Getting Started with the RTL-SDR and SDRUno

Over on his sdr4everyone blog author Akos has uploaded a tutorial that shows how to set up the recently released SDRUno with the RTL-SDR. SDRuno is a spin-off of the (recently acquired by SDRplay) Studio1 software. Although designed and tailored for the SDRplay, SDRuno also supports any radio with an ExtIO interface available, such as the RTL-SDR. The one limitation is that the maximum bandwidth of radios other than the SDRplay is locked to 1 MHz at most.

Akos’ post shows where to download and add the required ExtIO file (it’s the same one used for HDSDR) and how to start the RTL-SDR in SDRuno, as well as a quick tutorial on changing some settings and tuning.

We note that the fact that you need to install the ExtIO dll file to the documents folder seems to be a bug in the latest version at the moment. In future updates they may fix this, and then the ExtIO dll will go back to needing to be added to the C:\Program Files (x86)\SDRplay\SDRuno folder, as it was in previous versions. We’ve also heard one or two reports of users stating that they needed to add in the libusb-1.0.dll file as well, but we can’t confirm if this is actually required as none of our test PC’s have needed it.

Also, a recent post on Nobu’s blog shows how to get rid of the center DC spike in SDRuno by adjusting the Channel Skew Calibration. The post is in Japanese, but the gist of it is that you just need to adjust the fine tuning DC offset slider in the Channel Skew Calibration settings. Nobu also points out that a handy shortcut to getting the ExtIO window to display is to simply press the ‘H’ key.

Setting up the RTL-SDR for use in SDRuno.
Setting up the RTL-SDR for use in SDRuno.
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Trying to get Sdruno to work with the Nooelce Smart Tee XTR which is RTL2838 . I am trying the SDRuno 1.41 and
and in the SDR main box select OPT button I don’t get the select input button . Using Windows 10 64 bit .Can get HDSDR to work .


Using SDRPlay/SDRUno, I have to go into the ExtIO_RTLSDR settings EVERY time I launch the program and change the Direct Sampling to the “Q Input” setting. Is there not a way to store this permanently?


Try to use ExtIO_RTLSDR#

It has “Auto Q” direct sampling mode by default. It means that you can forgot about this setting, because it will be automatically switched between “Disabled” and “Q branch” depends on your current LO setting. When LO 24 MHz it will switch to “Disabled”.

RTLSDR cannot work below 24 MHz in “Disabled” mode. So, there is no need to switch it to manual selection, you cat set “Auto Q” mode and forgot about this option, the direct sampling mode will be enabled automatically 🙂


When you look at the download from SDRUNO make sure your opening the ext/io version there are two shortcuts in the folder. Hope that helps.


It is good article but the nowadays version of SDRuno, inside of select input menu, MISSING A GENERIC 2832 MENU, that means in a hungary says : baszhatjuk.


I would like to enable HF Direct Sampling with SDRUno using the RTL-SDR v3 dongle.

It uses the ExtIO_RTL2832.dll for settings but HF Direct Sampling is disabled. No options for q-branch are present. I tried several different ExtIO_RTL2832.dll files with the same results.


You can use this ExtIO:

It works through standard rtlsdr.dll from osmocom, but it also needs .NET Framework 4.0 Runtime to be installed in order to run.

It allows to use Direct Sampling mode for RTLSDRv3 in SDRUno and also has integrated DC remove filter (you can enable and disable it from settings window).


A little update v1.0.0.1, fixed setting save for gain:


Missing something ? i cannot find a way to get the RTL-SDR dangle to work, there seems no EXTIO dll included for the RTL-SDR


The instructions are very clear on that matter. They tell you to put the EXTIO file in the documents folder. They tell you that you can use the same one that is used with HDSDR or you can download another from the SDRPLAY site. Just because HDSDR uses it in the program files, I copied it there as well. Don’t know if that was necessary, but can’t hurt and mine’s “working well.”