Been getting this exact thing for the last three weeks running. Set up my Zoom H5 in the back room overnight and the static burst hits somewhere between 3:02 and 3:11 every single recording, never outside that window. What gets me is the burst isn't random noise - it has a consistent rhythmic quality to it, almost like breathing or a slow pulse pattern.
I've ruled out the obvious stuff. No HVAC cycling, checked the electrical, swapped the recorder and cables. Still happens.
What equipment are others using when this comes through? I'm wondering if certain frequency ranges are more susceptible, or whether the 3am correlation is genuine or just confirmation bias making us notice it more at that hour. Has anyone actually slowed these bursts down and analysed the waveform in Audacity or similar? I did a basic spectrogram and theres something structured in there that I cant quite explain. Would love to compare raw files with someone who's capturing the same thing.
