Been getting exactly this for about three years now, always in the window between 2:58 and 3:04. Not just static either - there's a kind of rhythmic quality to it sometimes, like something trying to modulate the signal. I've ruled out interference from nearby electronics because I tested with everything unplugged.
What I find interesting is the 3am thing keeps coming up across different researchers working completely independently. I've spoken to people at various NDE conferences who report the same anomaly on their recording equipment, not just EVP setups but standard digital recorders too.
Anyone tried running two devices simultaneously to see if the bursts appear on both at the exact same moment? That would help rule out a fault with individual equipment. I did this last autumn in my back garden and got simultaneous hits on three separate recorders which honestly shook me a bit.
Would love to know what software people are using to analyse the waveforms. I'm on Audacity at the moment but wondering if theres something better for picking out patterns in the static.