Still unsuccessful. I asked one of my colleagues that comutes 65km away by train to carry the transmitter in the backpack.

He lives at the 8th floor, and he has no buildings to his south. The receiver remained at my workplace.

It is almost line of sight, but not quite. Still, it is better than at my house.

But no signal for the entire night. And not even from the road back.

This needs some investigation.