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    • Timmy

      So should the price of the hardware be increased higher for everyone to pay the additional royalties on every device sold to the Via Licensing Corporation or else do some kind of oddball weirdness like the Raspberry Pi does ( http://www.raspberrypi.com/license-keys/ ) with the MPEG LA organisation ?

      The reality is that DAB+ is an open standard that unfortunately uses some licensed codecs. And the patent licensing cartel is ingenious, they bundle together a very large number of mostly software patents from multiple companies into a neat package and charge the maximum fee for ALL the patents in that bundle (for anyone outside of the cartel), until the very last patent in bundle has expired (in all countries if you want to ship your product worldwide). I think that might be sometime, possible around 2024 maybe (and probably 2027 for the last patents outside of the US) for the MPEG-4 HE-AAC codec used in DAB+, but it could be earlier.

      ref: https://en.wikipedia.org/wiki/Advanced_Audio_Coding#Licensing_and_patents

      • Bjarne Mjelde

        You have free DAB+ decoders to be used with SDRs. But one DAB multiplex is around 1500 kHz wide, while the HF+ can only sample 660 kHz alias-free.

  1. Eric Carter

    I am at the assembly stage of making the RF Impedance transformer. The Amazon.de seller included wire, but without differing colors. I am so glad I found this website.

  2. Ste

    Hi, so I came across this post last night and followed the guide – everything went great and I was happy to find I could now find HF signals with my V3 dongle, even without a proper antenna. It worked all night, then when I tried it this morning Console would not start the radio at all. No error messages, I clicked the button to start the radio and nothing happened. In the end the only way I could get it working again was to uninstall Console and reinstall it with the standard drivers. The PC was shutdown last night and restarted this morning. It’s a newly built high end Ryzen system. Whilst Console was not working, I tried the dongle with HDSDR and SDRUno on the same machine, as well as in Cubic SDR and GQRX on another machine and it was working fine. The only issue was with Console. Any ideas? I really want to use Console over the other programmes, and I’d really like to use the HF capability.

    • Jock Mckie

      Using latest software. if you have sdruno shortcut on the desktop, right click on the the shortcut, open file location, look at files, you will see two shortcut files files, “SDRuno.exe” and “SDRuno.EXTIO.exe”. it seems that the default on the desk top is SDRuno.exe. where as for rtl-v3 dongle use “SDRuno.EXTIO.exe.” you can make another short cut by highlighting and right clicking the file and selecting “create shortcut”

      • Ste

        Nope that’s not the problem. I never ever ever use desktop shortcuts, and I am not trying to use SDRUno either, I am talking about using SDR Console here, SDRUno is working fine for me. This topic is about using an alternative driver to enable HF without an upconverter in SDR Console, it has nothing to do with SDRUno.

    • JDow

      All that comes to mind is unplug the dongle and plug it back in. Also make sure you are working out of the same directory into which I put the rtlsdr.dll and libusb*.dll file. If you are launching from a shortcut then make sure the shortcut points to the SDRC directory as the working directory.

      {^_^}

  3. Eric Brombaugh

    Heh – isn’t “explaining DSP without math” kind of like “explaining painting without color”?

  4. Anonymous

    Readers beware: this is a well-intentioned document, but the examples (or interpretation of examples) showing the Nyquist limit are wrong. All of the plots in Fig 4 are perfectly well sampled below the Nyquist rate. The problem is that by using excel to interpolate between the samples, the author has created a visually false representation of what is actually going on. It is a shame, because it is easy enough to visualise the Nyquist limit and the effects of aliasing, but the explanation (“gone!”) associated with the plots is wrong.

  5. snn47

    Did anyone find some real information on the filter besides just the quoted insertion loss like e.g.
    – filter bandwidth,
    – how fast the filter drops off,
    – the max. attenuation or
    – IP

    PS: I remember that UAT on 978 MHz was implemented by FAA so far in the US only for operational use in the Alaska region. It was just recently announced to be extended to other states.

      • snn47

        Thank you for the curves. Imho the insertion loss representation at amazon is quite misleading to potential buyers, since it does not clearly identify the total insertion loss
        – 978 MHz insertion loss (above 3 dB): 2.73 dB @amazon vs. total insertion loss of 5.78 dB @978 MHz
        – 1090 MHz insertion loss (above 3 dB): 2.88 dB @amazon vs. total insertion loss of 5.88 dB @1090 MHz

        Can you confirm if I identified the logo correctly for 1090 MHz as Tai-Saw Filter, possibly TA1090EC (insertion loss 2.3 dB typ. 3.0 dB max) and the 978 MHz saw filter could be a TA0395a (insertion loss 2.2 dB typ. 3.5 dB max) since there don’t seem to be to many manufacteres for 978 MHz.

        If you check the filter curves they are quite wide and provide not much more attenuation than 10 dB 20 to 30 MHz above and below the center frequency.
        Depending the frequencies in use on your location signals can exceed -40 dBm (meassured) on multiple/many channel from e.g. :
        – cell phone base stations below 960 MHz
        – ground and aircraft transmitter
        – L-Band PSR between 1215 MHz and 1400 MHz

  6. qrp

    I wrote custom ExtIO for RTLSDR. I named it ExtIO_RTLSDR#, because it is written in c#. It allows to use direct sampling mode in SDRUno, use custom sample rates, has logging and integrated DC remove filter (can be disabled). It works through standard rtlsdr.dll from osmocom. May be it will be interested for someone… 🙂

    Here is download link: https://drive.google.com/file/d/1xW8YlmQfV-VSsJXnLhXTWZ1mduLQ5Xe2/view?usp=sharing

    Since it is written in c#, it requires .NET runtime 4.0 to be installed. Usually it is already present on modern windows systems, but may be missed for some reason, so in that case you can install it from this link: https://dotnet.microsoft.com/download/dotnet-framework/net40

    If you found some bug, or want some additional features, please let me know. 🙂

  7. Steve K2GOG of HVDN.org

    Aside from the comment on high loss due to PCB design, this duplexer can also function as a band-pass filter by using only one port at a time, with the other terminated. This may come in handy to reduce some level of interference. Not sure I would want to use an LNA with this board though.