Stefan and Paul,
Each new 2970 Hz experiment your series is exciting; the results today with stacked 10:00 UT - 18:00 UT are more so. Compliments on the experimental methods and good results, and exploration of narrowband skywave propagation through what is apparently uncharted frequency/distance territory. Quite exciting.
73,
Jim AA5BW
Hi Paul, ULF,
Sorry for my late reply.
The transmission takes quite long, so there is no need to stress with my answer :-)
Thanks for the overview of the signal received in Bielefeld. Quite strong and stable! There have been attempts by DK1IS to see a trace of my signal. He is planning to build up a VLF/ULF grabber in JN59VK53, quite a quiet location :-) The distance is less than Bielefeld from here, so the signal should be well detectable...
I'm excited! 3 sigma. I am curious how this looks in one of your spectra!? Could you generate one, for the history :-)
How much sigma do you need to make a secure claim that this is my signal?
Day by day the SNR should become higher now, so your phase measurements and blanker adjustments can become more optimised. After some time the night time signal may come through as well.
Yesterday increased from 180 mA to 190 mA, another QRO of 0.5 dB.
And now since sunday there is a 'strong' and clear peak at IK1QFK in 5 wavelengths distance: http://www.webalice.it/rromero/live_cumiana/last-LFtest_2970.jpg !!!!!!!!!!!!!!!
Currently this peak is the strongest in the spectrum and in all spectra covered by the peak hold graph! Also it is spot on the frequency and it is already the 4th pixel in one line of the spectrogram.
I have saved each capture, i.e. each spectrum so one can scroll through the pixels later.
Unfortunately there was some confusion, the spectrogram had to be reset 2 times. A whole week was lost that way! But never mind. The transmission will run for a few days longer until there is a longer dash visible.
Renato said there will be QRN in the coming days. Hopefully this is not so expressed in that range of the spectrum. Local thunderstorms may cost a few dB.
Assuming an average SNR of 8 dB in 5 uHz, i could try a 2 character EbNaut message over that 5 wavelength distance. For example http://abelian.org/ebnaut/calc.php?sndb=8&snbws=0.000005&snmps=&code=16K21&sp=600&crc=22&nc=2&submit=Calculate
A two character message in 6 days! That would be one of the slowest ever i guess.
But can this work? The day-night phase difference may mess things up. Probably stacked day-time messages could be even faster. At least it will be interesting...
73, Stefan
Am 21.03.2017 15:02, schrieb Paul Nicholson:
I wrote:
> So far, still not a trace here.
Well, now perhaps a hint of a signal. Only 3 sigma
so not much but is interesting because it's on the
right frequency and only present in E/W loop and
E-field.
I gave up doing long narrow integrations and tried
stacking various parts of the day.
The 'hint' appears when I stack 10:00 to 18:00 UT
each day.
Also the phase angle between E-field and E/W loop is
unusual but it is so weak it is hard to be sure.
I'll work on trying to resolve this better. It will
either improve if real, or vanish if not.
Quite a steady signal at Bielefeld, day and night:
In 23.15 uHz (12 hour Fourier transform)
Days, 06:00 to 18:00 UT
2017-03-11 11.3 dB
2017-03-12 11.2 dB
2017-03-13 11.5 dB
2017-03-14 10.1 dB
2017-03-15 16.3 dB
2017-03-16 12.3 dB
2017-03-17 11.6 dB
2017-03-18 15.2 dB
2017-03-19 15.6 dB
Nights, 18:00 to 06:00 UT
2017-03-10/11 11.4 dB
2017-03-11/12 15.8 dB
2017-03-12/13 16.0 dB
2017-03-13/14 13.6 dB
2017-03-14/15 15.8 dB
2017-03-15/16 15.0 dB
2017-03-16/17 12.3 dB
2017-03-17/18 11.6 dB
2017-03-18/19 14.3 dB
2017-03-19/20 10.9 dB
--
Paul Nicholson
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