Hello,
I noticed that there is always unknown continuous noise near 4hz (roughly between 3.3-4.7hz), sometimes it becomes stronger (even reaching 2000 counts and 1.2 STA/LTA ratio).
The picture below shows it becomes stronger.
The picture below shows the noise at 4 o’clock(UTC+8) in the morning.
Does anyone know what causes it, my station is RED68.
Thanks.