More Reports and Tests on the RTL-SDR V3

Recently we sent document author “D. B. Gain” a sample RTL-SDR V3, so that he could write a review and guide on it. The guide is now available at, and the link to the guide is labelled “The RTL-SDR V3” and is under the “HOW TO …” section. The guide reviews the V3 and tests it out on reception of HF signals. He uses an off center fed dipole up around 30ft, RG6 cable TV coax feedlink and a Barker and Williamson 30 MHz low pass filter. He write this valuable piece of advice:

The larger the antenna system, the greater the gain – usually. It doesn’t take too much RF to overload the V3 dongle, so a 20ft piece of wire will do better than say a 430ft wire loop atop some phone poles. Use an attenuator if you have one. Remember the issue with AMBC swamping where AM stations pop up in various parts of the HF spectrum and use a preselector and/or attenuator if you can. Shortwave broadcast stations can also create spurs in the V3. Some radio parts houses carry a variable attenuator meant for cable TV or VCR player use that can be employed at HF with the use of some F to UHF or whatever connector your antenna system employs adaptor, this can be installed in the antenna system and adjusted to result in least usable signal getting to the V3, which assures best dynamic range. Then one would adjust the FFT Spectrum gain in your SDR control app of choice to best level on a quiet band, say 14MHz. This will ensure you don’t have to mess with adjusting the gain on lower frequency bands just to keep the band noise baseline above the bottom of the FFT window.

Mr. “Gain” has also uploaded several other screenshots of the V3 in action on HF in this gallery.

The RTL-SDR V3 receiving ham radio signals on 40m.
The RTL-SDR V3 receiving ham radio signals on 40m.

Mikael Dagman (SA6BSS) also wrote in to let us know about how he’s been using the V3 to receive WSPR. He writes:

For an experiment I have set up a SDR play and a RTL blog v3 dongle fed from the same antenna (butternut hf9) through an antenna splitter, grabbing Qrss signals on 40m, on the v3 I added a bpf. The v3 is run from SDR sharp q-branch RTL AGC on and both radios feeding separete instances of spectrum labs, doing wspr as the same time on both radios, there I hardly any difference, maby one spot out of ten the rsp get 1 db more in sn . Without the filter on the v3 its completely falling apart but with the filter inline I am more then impressed!!

I will stay on 40m for a couple of days trying to catch a ZL station tx:ing with 1.1W Qrss with the v3, (that’s 16000 km away) I will then qsy to 30m with the v3 where there is more signals to look at.

Spectrum available here
You see that bottom spectrum have the name RTL upper left corner.

Over on YouTube Leif (SM5BSZ) has also uploaded a video where he compares the performance of the RTL-SDR V3 with the Airspy+SpyVerter. Of course the V3 cannot compete with the higher end Airspy, but still performs decently enough for a beginner. If you are strapped for time, the results are concluded at about 28 minutes.

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ooooo yeeeessssss !!!!!!

Lakis Papadopoulos

Anyone had problem with the HF (lpf-preamp) part ?
I noticed malfunction (not working sometimes) and today seems like stopped at all.
There is a very small “lpt” smd filter-preamplifier which is terribly hot (cannot keep the finger on it).
I bypassed it with a capacitor about 10nF and HF receiving comes back.


Must we say “beginner” for these radios? How about “budget conscious” instead, it would be more accurate, beginners aren’t the only ones using these, they perform quite well in most applications.


Anyone with the new V3 dongle have trouble with the stock antenna not making connection with the dongle? When i screw it in all the way, it doesn’t get any signals (no connection). When i unscrew it .5 – 1 turn, it makes connection and there are signals. I started to take it out of the case but one of the screws looks like it was already cross-threaded and was tightened too tight so I’m stuck with one side on and a screw unable to remove….

Mikael Dagman

For the above info I would like to ad that I´m also feeding each radio to separate instances of wsjt-x doing wspr,
Lookng at 40, there is a daily upload of how many stations I have heard, the SDRPlay is SA6BSS/RX and the V3 dongle is SA6BSS/RTL, the rtl is one or two spots behind the play in a 24hours run, also I just found out that increasing the samplerate of the dongle somhehow helps getting better sn, so 1.4MBPS instead of 0.25 give 1-2 db betters sn comparing it with the play.