Topband: identifying noise source

[Maciej Wieczorek]

GM,

I recently have some strange, pulsating noise on all 300 deg / NA beverages. 
Maybe someone have already experienced anything like this  - what kind of 
device it can be? Here is a recording on wide filters in AM, around 3,4MHz 
(maximum signal).

https://drive.google.com/file/d/1zTWirLyNiD2aYd7oJQjt8HhG9rgttcvn/view

It's starts late in the evenings and can be heard till 8-9:00 AM. In 
daylight it gets stronger.

I actually have 2 different RX arrays for NA, the distance is abt 300m from 
each other, but the noise is abt the same level on both antennas. I guess it 
means the source can be even few km's away?

73
Mac SP2XF/ SN2M