New RTL-SDR Drivers and SDR-Console ExtIO Available: Bias Tee Support, Direct Sampling, Tunable IF Filters and Improved Gain Profiles

Recently two branches of RTL-SDR drivers were updated. Over on GitHub racerxdl’s librtlsdr branch adds bias tee support for our V3 dongles to rtl_adsb, rtl_fm, rtl_power and rtl_tcp.

For SDR-Console users jdow’s ExtIO and driver now has an option to enable the direct sampling mode, which is allows the HF mode on our V3 dongles to be activated. The ExtIO module can be downloaded from her Google drive.

To use Joannes drivers download the SDRconsole folder by right clicking it, and selecting download. Then copy files from the x86 (32-bit) or x64 (64 bit) folders into the SDRConsole folder, replacing any files that already exist. Run the RtlSdr Catalog.exe file, then open SDR-Console and from the definitions choose RTL-SDR(Full). Then in the Radio Configuration settings you can choose to use the Q-branch, which will automatically enable the direct sampling mode when tuned below 24 MHz.

SDRConsole with a V3 dongle and HF Direct Sampling.
SDRConsole with a V3 dongle and HF Direct Sampling.

We’ve also discovered that Joanne has been working on RTLSDR++, which is a driver upgrade that includes some pretty interesting enhancements. When running Joanne’s drivers in SDR-Console we also see options to change the IF filter bandwidths of the R820T2 tuner. This is very useful as this allows you to control the preselector on board the R820T2. You can use this to attenuate strong out of band signals. Her driver also has improved gain profiles. One gain profile is optimized to reduce IMD distortion (prevent overload and images), and the other is designed to optimize sensitivity.

RTLSDR++ Driver: New IF bandwidth settings for preselection.
RTLSDR++ Driver: New IF bandwidth settings for preselection.
RTLSDR++ Drivers: New Gain Options
RTLSDR++ Drivers: New Gain Options

In addition Joanne has also created RtlTool.exe which is a GUI replacement for rtl_test.exe and rtl_eeprom.exe. It can be used to test for lost samples on your RTL-SDR and to flash the EEPROM memory. Most RTL-SDR dongles on most PCs are stable up till 2.56 MSPS, but this tool can be used to check. It can also be used to set the dongle serial number, vendor ID and name by flashing the EEPROM which most RTL-SDRs contain.

There’s also the RtlSdr Catalog tool which also helps manage multiple dongles being connected to the PC at once. See the readme file for more information on using this tool.

All these programs can also be downloaded from Google drive. Her RTL++ driver is also open sourced and available on GitHub.



  1. Sivaramaprasad Kappagantu

    I very much request the experts to post a tutorial video as to how to configure SDR Console software for SDR RTL2832 + R820T (which I purchased from FabtoLab details in this link ) Although I could configure to receive FM stations, I am not able to configure for MW/SW stations. Kindly post a tutorial Video for the benefit of people like me.

  2. Sivaramaprasad Kappagantu

    Thank you for the write up and the files shared. I am using SDR Console V3.0.2 and configured my RTL SDR in the software. However, I am able to get only local FM stations. But I am not able to get the MW/SW stations in the frequency range of 100Khz~30 Mhz. I hope the details and files provided in this article shall solve my problem, I shall try tomorrow afresh in the morning.

    • JDow

      If you bring up the Radio Configuration panel and mouse around a little you will find an option “Direct Sampling”. Tick it AND select a frequency below about 28 MHz. What you get may and may not be useful. The code came from an rtlsdr that claims direct sampling performance. I gave it a brief try and decided the mode was trash so never rechecked that mode again. It’s too close to useless. Feel free to fork the project as needed.

      That said you SHOULD be able to receive a whole lot more than FM radio if you use a modest antenna, NOT the ridiculous spike that comes with mode dongles. The desirable antenna length for a simple suction cup vertical is about 2.94/F with F in MHz. The tolerance on this for a receiver is VERY high so don’t get anal about more than 10% accuracy. Then set the gain, RF Gain on the home menu, to about 19.7 dB or 20.7 dB. You should be able to find aircraft, probably between 120 MHz and 135 MHz for example. In the US, at least, there is a whole lot more including several ham bands within the coverage of the dongles.


  3. gmvoeth

    It would be nice if someone could possibly collect all the SDR drivers into one collection to be downloaded as a zip or rar file

  4. Sergey

    The new driver with SDR Console works fine.
    How to enable direct sampling in the SDRServerManager program?

    • jdow

      You don’t. I never put it in because it’s utility was too low for what I needed. Feel free to fork the project. The sensitivity is rather lacking unless you use a full size antenna. The mode for operation below 50 MHz works on leakage through the mixer stage. Without filters in front of it you are never going to be sure precisely what you hear. So for my interests, ham radio reception, it won’t do. For example it will not work on 20 meters and 10 meters due to Nyquist nulls from the 28.8 MHz sample rate.


  5. jdow

    Let’s straighten up some interesting points here. My rtlsdr++ is not an ExtIO driver. It is a customized Windows replacement for rtlsdr.dll itself with some fun stuff on the side. You can read my ramblings in the text files which accompany the executables. Sources are up on GItHub. Username is ms-jdow.

    RTLTool is a separate tree. If need be I am certainly willing to toss it up onto GitHub as well. It useful for testing different modes for drawing down data. (Sync/Async doesn’t make a material difference in performance if done right.) It also allows renaming dongles. This is important if the catalog tool is used. If you have multiple dongles plugged in this helps at least SDR Console startup faster and delivers the dongle you want not the first one seen.

    And there is an SDR Console “Source*.dll” that wrings more performance out of the dongles than Simon’s default driver. For Simon’s SDR-Radio (V3) you download the “SDRSourceRTL2832U Distribution” file. Unzip it some place handy. Drill down to the x64 or x86 directory. Then copy at least the SDRSourceRTL2832UFull.dll and rtlsdr.dll files into the “SDR-Radio (V3)” folder in the appropriate program files folder. The catalog and libusb files are there for convenience. The catalog tool is a TINY tray tool that keeps a catalog of rtlsdr dongles on your system – as long as they all have different serial numbers. With it in action SDR Console starts faster. This is not true with SDRSharp due to the way it operates inside. I use it as a tool in the Startup folder with a “-quiet” parameter.

    But, I repeat, it is NOT an ExtIO thingus at all.


  6. CW

    Just downloaded the latest sdr console v3, installed this as shown… It wont switch to q sample or I sample, stays in quad. I am using the v3 dongle.

    • LU

      I fixed my problem.

      I change and Add a new Dongle Device “RTL-SDR FULL” in SDR-Console options, now you can view a NEW Driver options.

  7. Jeffery Legere

    This was not very well written. first it says there are two branches that are updated, then only talks about one. Then he starts talking about rtlsdr++ and mixes that in for more confusion over what can be done with the one branch.

    • admin

      First branch is racerxdl’s from the first paragraph. Second is jdow’s. Jdow’s branch has more to show so the article is mainly about that.

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