jks
About
- Username
- jks
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Direction Finding and linking existing KiwiSDRs
Christoph's latest post on https://github.com/jks-prv/Beagle_SDR_GPS/issues/130 shows how his GPS timestamps are within 20 usec of DCF77 (77.5 kHz) as received by a couple of Kiwis a few hundred km distant. Really fantastic work!
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Direction Finding and linking existing KiwiSDRs
There have been three or four people recently express interest in working on HFDF. Some on here or on Github issues or in private emails to me. I'll try and point everyone to this thread.It is important to note that V/UHF DF is significantly different from the HFDF problem due to the issues imposed by the nature of the ionosphere at HF. It is much more complicated than you would expect. But we have this wonderful resource: lots of geographically diverse Kiwi installations and now GPS timestamped IQ data thanks to Christoph's recent work (https://github.com/jks-prv/Beagle_SDR_GPS/issues/130)A recent example of V/UHF DF using RTL-SDRs: https://www.rtl-sdr.com/localizing-transmitters-to-within-a-few-meters-with-tdoa-and-rtl-sdr-dongles/Slideshow about HFDF techniques: http://www.g4axx.com/HF_Radio_Direction_Finding.pdf -
WSPR and who is logged on
I understand. I was just pointing out there was another source. A general, well thought-out overhaul of the UI needs to be done.
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DRM demod? [yes, external app Dream now working!]
No problem. I'll add a link to your video on the Kiwi home page too. -
Sound recording from multiple opened browse windows for diversity reception?
Aww, I'm such an idiot. The answer is so simple. The passband isn't wide enough! When you click the IQ button on the Kiwi it sets IQ demod mode, but also sets a default passband. But that's just how the Kiwi user interface works.With kiwirecorder when you change the mode with "-m iq" the low-level command it's sending on the web socket only changes the mode. It doesn't know anything about the passband. You'll get whatever the last passband was. The default for a new Kiwi connection is USB 300 - 2700 (2400 wide).This is of course not what you want with IQ mode. So try something like:python kiwirecorder.py -s fenu-radio.ddns.net -p 8073 -f 3965 -m iq -L -5000 -H 5000Which sets a DSB passband from -5 to +5 kHz for use with DRM. Using this I was able to feed the recorded file to Dream with no problems decoding at all.
