jks

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jks
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  • Flatness of KiwiSDR response < 500 kHz?

    jksjks

    From an hp 8657D coupled with a "gimmick" cap. No front panel sweep on the "D" unfortunately (HPIB only). So manual 10 kHz steps. Kiwi spectrum averaging and peak function to capture. Except for < 150 kHz where there is a clear drop-off, the scalloping is probably FFT spectral leakage since I never learned how to do my post-FFT DSP properly.

    I see SMPS harmonics that are much louder than the fundamental all the time. Even into HF sometimes. It just baffles me. And when the fundamental is an unstable carrier, at HF it often turns into such a wide signal that the harmonics bridge together and it looks like a huge bump in the noise floor!

    kiwi.<450kHz.flatness.png


    ka9q

  • Suggestion to tweak default bandwidth settings [fixed in v1.454]

    jksjks
    http://forum.kiwisdr.com/index.php?p=/discussion/comment/11862/#Comment_11862


    N1NKM

  • v1.456,458,459

    jksjks

    Short version: Old behavior restored so external apps, including those using kiwiclient et al, should work as before. But Kiwi web interface uses new changes as described below.

    v1.459 May 23, 2021

      Waterfall / spectrum:

        Fixed the CIC compensation added to the last release.


        Added waterfall interpolation URL parameter "wfi=N" e.g. kiwi:8073/?spec&wfi=13

        Also available as an API parameter on the waterfall web socket: "SET interp=N"

        Value N below. Add 10 to enable the CIC filter compensation.

         

        The value below answers the question: "What to do when multiple FFT values

        contribute to a single waterfall/spectrum pixel bin". In most cases the FFT

        is larger than the 1024 display pixels of the waterfall (or external application).

         

        0 take max (old and continuing server default for kiwiclient, external apps etc.)

        1 take min 

        2 take last 

        3 do drop sampling

        4 take cumulative moving average of values

        ...

        13 drop sampling + CIC compensation (new Kiwi browser interface default)


    PowernumptyUR5VIBHB9TMC

  • v1.456,458,459

    jksjks

    v1.457,458 May 21, 2021

      Waterfall / spectrum:

        Fixed low-level post-FFT artifacts spotted by Marco's SuperSDR app. Thanks Marco!

        Added CIC filter compensation to better level spectrum at top end.

       

      FAX extension:

        Added GM-11F Sevastopol 7090.9 kHz per fabrys on Kiwi forum. Thanks fabrys!


    njcHB9TMCUR5VIBfabrys

  • v1.456,458,459

    jksjks

    From the CHANGE_LOG file:

    v1.455,456 May 19, 2021

      Admin page

        Config tab: Added button to reset passband fields to default values.

        Connect tab: Improved proxy setup UI.


      Right-click menu: Added "snap to nearest" mode. Setting is remembered/restored per Kiwi

        visited just like freq/mode etc. Waterfall cursor differs when snap mode active.

        When snap is active the freq step keys (j/i, left/right arrow keys) are modified so

        the ctrl/alt-key steps the smallest amount and the unmodified key steps the same

        amount as the snap (e.g. 9/10 kHz on MW). Usually the unmodified key step the

        smallest amount.


      Changes to more easily support general (even non-SDR) FPGA development.


    PowernumptynjcUR5VIBrz3dvpdl7awlHB9TMC