16 Mar 2010

More on the 8.97kHz DX by DK7FC yesterday

This is a combination of two screen shots showing the signal received in the UK (830kms!) and in Germany (180kms) from the 8.97kHz VLF test transmission by DK7FC.  The antenna was a kite supported vertical.  See http://www.qrz.com/db/DK7FC for more info and pictures. This was the email I got from Marcus DF6NM when I asked if the transmission had been definitely identified:
Dear Roger,
well, I think yes.
Attached are the two spectrograms from Paul (top) and myself (bottom), stretched to the same timescale 14:00 to 18:00 UT. The frequency was accurately as stated before, within a few milliHertz. This also was the first time I have seen a stable carrier, in a week since I started my grabber.
The indicated QRSS 120 message is only my guess of what Stefan might have started to send, before suddenly quitting. He had actually mentioned before that his generator might be running out of fuel sooner or later.
For receive, Paul used a pair of magnetic loops, with automatic beam steering for minimum noise. I have my LF Marconi, currently lowered to 3 m above the roof. The VLF signals are tapped off at the foot of the transformer coupled LF receiver input, using a 33 nF capacitor inserted into the ground line.
Best 73,
MArkus (DF6NM)

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