Hi Edgar,
It looks like my emails are not coming through to your email providers
so i'm writing you here.
Thanks for the start of the project and the first captures.
DL0AO is running a spectrogram showing NWC on 16.8 kHz. I also started
a spectrogram on NWC a few minutes ago, visible on the bottom of
http://www.iup.uni-heidelberg.de/schaefer_vlf/DK7FC_VLF_Grabber2.html
I'm not sure if it makes sense to watch NWC from here and expect the
same propagation on 17.47 kHz.
JXN seems to be quite weak everywhere, relative to HWU for example.
If there is VTX on 18.2 kHz with a strong signal then it may be hard to
see HWU at all?
Your spectrogram shows the right frequency range and the scroll rate is
fine as well. Based on the observations at DL0AO, NWC has its maximum
SNR during the evening, as expected. But the time is much longer than
we expect, based on the experiments on LF. It rather seems to be open
for 7 hours! So it may be useful to reduce the scroll rate to 40
seconds per pixel even.
I said that a FFT bin width of 1 Hz is fine. But it is better to go to
a value as small as possible, e.g. FFT input size 32768, decimator 6,
SR=48000, center frequency 17470. This gives 244 mHz FFT bin width.
Worth a try...
Good luck and i hope to see a trace of JXN and HWU with the longer time
covered and lower FFT bin width...
Update: On my spectrogram, NWC has its maximum between 18:00...22:30
UTC.
73, Stefan
Am 17.02.2018 22:53, schrieb Edgar:
Hi Stefan,
OK, first step is to see what signals can be received overnight from
JXN and HWU.
Images can only be uploaded once per day.
Regards, Edgar
Moonah, Tasmania.
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