Hi Jacek / VLF
On 24/04/2017 16:08, Jacek Lipkowski wrote:
Eddie (at 750km distance) and especially Markus (at 180km) can't receive.
The only other explanation (apart from lower qrm levels) might be the
software used.
QRM.
Stefan suggested running a 366mHz spectrogram at 6470 Hz, see
http://www.g3zjo.talktalk.net/vlfgrabber.htm VLF2.
The bands of QRM are unstable spaced every 100Hz still visible at 8 kHz
I have seen a strong harmonic drift up to 6470 Hz. The signal strength
varies giving the appearance of having some propagation characteristics.
Present from <>= 05:30 to 00:00, boiler, heating controller, smart
metering ?
Closest to my antenna, to the South, is a single story, special needs
home, I assume they have resident staff, they may spring into life early
in the morning. I like to blame them for at least some of the
unexplained QRM. I have never had contact with them in over 30 years,
despite being only 20 m or so from my antenna there is little of the
building visible, going to visit them would take a journey of around
0.5km and two private access roads.
I have sent my immediate closest neighbour to the North away for a few
days, his usual band of QRM has gone with him :-)
73 Eddie G3ZJO
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