jks

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jks
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  • Upgrade between 1.235 and 1.236 appears to fail?

    Okay, I see the bug. It was actually introduced in v1.235 but doesn't get triggered until a restart (like when updating to v1.236)

    I'll fix it in today's update. But the issue now is that you'll either have to temporarily turn off WSPR auto-run or go through the manual update procedure one more time to get past this problem.
    ve6hfdVK3KHZ
  • kiwirecorder.py crashes

    Done..
    WA2ZKD
  • v1.223: CIC filter compensation implemented, possible DRM benefits

    I should have done this long ago, but I finally figured out a simple way to implement CIC filter compensation by empirical measurement. The before and after pictures below show the result. No more 10 to 15 dB roll-off at the ends of a wide passband. This will improve wide-band AM frequency response and more importantly wide-band IQ mode uses. DRM in particular might have an easier time without the roll-off (see DRM PSD plots below).

    IQ mode, 12 kHz passband, 10 dB/div:
    (display is from the new audio FFT)
    image


    With CIC filter compensation. Note flat passband:
    image


    DRM PSD before and after compensation:
    image


    image
    PowernumptyWB4klj
  • v1.223: CIC filter compensation implemented, possible DRM benefits

    I should have done this long ago, but I finally figured out a simple way to implement CIC filter compensation by empirical measurement. The before and after pictures below show the result. No more 10 to 15 dB roll-off at the ends of a wide passband. This will improve wide-band AM frequency response and more importantly wide-band IQ mode uses. DRM in particular might have an easier time without the roll-off (see DRM PSD plots below).

    IQ mode, 12 kHz passband, 10 dB/div:
    (display is from the new audio FFT)
    image


    With CIC filter compensation. Note flat passband:
    image


    DRM PSD before and after compensation:
    image


    image
    PowernumptyWB4klj
  • v1.221: Audio FFT added

    The new 8-channel Kiwi configuration mode trades two of the zoom waterfalls for the ability to have an extra 4 audio-only receiver channels. I.e. the original RX4/WF4 mode, where each receiver channel was paired with a waterfall, can be replaced by an 8RX/2WF mode where only the first two channels have a waterfall. The other 6 channels get a “blank” waterfall and spectrum display (see this post: http://forum.kiwisdr.com/discussion/1233)

    The v1.221 release now adds an audio FFT in place of the zoom waterfall / spectrum for those channels that were formerly blank. This is possible because all the FFT processing is done in Javascript on the browser. No additional FPGA, Beagle or network bandwidth resources are required.

    However, this scheme has its limitations and also a number of known bugs that are being worked on. When I have a little more time I will list them. Until then please give the audio FFT a try.
    PowernumptyLonecrow