IW4DXW 8270 Hz Carrier detected – Italian VLF QRB Record

After months of test I finally detected the VLF carrier signal from Riccardo IW4DXW.
Today, probably thanks to a particular propagation condition on VLF, was possible for me to “read” during the entire daylight the signal from Riccardo’s transmitter. Unfortunately with the first rain drops the signal was cancelled from my spectrogram. But I don’t know if this is the real cause of the signal disappearance.
Here the detail of captured spectrogram where is possible to see the weak signal.
Blue arrow for the trace, the red one the signal peaking.

The distance from me and Riccardo is about 385 km, 10 km more than fromRenato Romero that received and decoded some EbNaut signal from IW4DXW.
To receive the 14uW radiated from Riccardo’s antenna I’ve used a 40 turns loop on NW-SE orientation.
loopVLF ik0vve

On top is possible to see a whip antenna always for VLF, I’ve tried to use both antennas together, but their proximity caused some problem mixing the signal of the whip in the loop and viceversa. So the next step will be to separate them.
Despite the nice free space that you can see on the photo I’ve a large amount of manmade noise from houses on the environs and this is a real big problem for my radio activity, especially for very weak signal reception.

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