jks

About

Username
jks
Joined
Visits
21,978
Last Active
Roles
Member, Administrator, Moderator
Points
203
  • Any tools to save KiwiSDR waterfall to image ?

    Yes! Right-click on your mouse to bring up the Kiwi utility menu. This is an often overlooked feature. If you have a laptop like a Mac there are different ways to configure the track pad for right-click in addition to the usual left-click (I use the two-finger tap method). One of the menu entries is "save waterfall as JPG". This feature was contributed by Peter, VE3SUN.

    But this is a manual operation. You're probably interested in automatic waterfall recording.

    The kiwiclient waterfall code is currently only for gathering statistics and not saving the waterfall image. But with some code changes it could probably be made to do that.
    kovalr
  • Any tools to save KiwiSDR waterfall to image ?

    To be more precise about the kiwiclient waterfall tools. There are three facilities:
    • The --wf option of kiwirecorder (note not kiwiwfrecorder) prints statistics.
    • Kiwiwfrecorder (note not kiwirecorder) is a specialty program Christoph wrote that saves waterfall data together with GPS timestamps as Python Numpy array format file (.npy) which with some code changes could probably be an image file as well.
    • microkiwi_waterfall.py is a simplified version of kiwirecorder --wf that Marco wrote. A version of which runs his Dynamic SNR Map website http://sibamanna.duckdns.org/sdr_map.html
    kovalr
  • comments on synchronous AM

    I'm simply using SAM code from Warren Pratt's excellent wdsp package as pulled from the Teensy-ConvolutionSDR project. So I don't know too much about how it works. The code can be found on your Kiwi in the file /root/Beagle_SDR_GPS/rx/wdsp/SAM_demod.cpp

    It has its own internal PLL code and does not use Christoph's C++ PLL code that is shared by the IQ and timecode extensions. Comments in the SAM code mention that the PLL zeta and bandwidth should probably be adjustable for varying conditions (e.g. dx, "medium", "fast"). Right now they default to a zeta of 0.65 and b/w of 200 Hz.

    With the recent reorganization of the noise blanker/filter controls there is now some empty space on the audio tab of the main control panel. Perhaps some SAM PLL adjustment controls could be added there.
    ka9q
  • Typical DRM SNR for decode?

    Antonio's excellent blog has information that WINB may indeed carry data on the LSB portion of the signal: http://i56578-swl.blogspot.com/search?q=winb
    ka9q
  • Problem with massive RFI after changing router

    Changing the external SMPS is fine. But there is another issue that is more difficult to deal with. The use of internal DC-to-DC converters (that are also SMPS) directly on the PCB of the device.

    These days it seems a lot more devices, including PC motherboards, are powered with higher voltage from the primary supply. Then high-efficiency "point of load" DC-to-DC converters are used right at the consuming load. In the case of your router the external SMPS is now 12V instead of 5V and there is almost certainly a 12V-to-3.3V (or even less) converter internally (chips don't run on 5V these days and in many cases don't run on 3.3V either except maybe for I/O).
    ka9qjohnk5mo