I've been dealing with S7 static on 40 meters ever since I got started a few weeks ago. It's so bad that I have to use my RF ATT so that the static is not deafening.
I did some research about finding noise sources (mostly wall warts) and common mode noise as well as the benefits of ferrite chokes. I have tried choking the antenna feedpoint as well as the point before entering the house- to no avail.
My current setup is a TS-830S with coax going out the window to a dipole up in some trees. At the dipole feed point is 8 loops of RG-8x clamped by a 1" ID mix 31 ferrite bead. That coax runs to a T connector right next to my house. The T connector is clamped onto a ground rod. The bottom of the T has a Palomar Engineering bleeder resistor. The other end of the T has 8 loops of LMR-240 in another clamp on 1" ID 31 bead before entering the house. Just at the feed point on my rig, I have another 8 turns into a toroid (#31).
Before the chokes and grounding- it was just a run of coax straight to the radio from the dipole. It made no difference either way.
Then one day I decided to try 40 meters at 2 o'clock in the afternoon. It was quite dead. In addition to that, there was no noise at all. We're talking less than S1. I turned off the radio and went about the rest of my day. I cam back at 8pm and turn the radio on. This time there was tons of activity and S7 noise. The noise is just static. No hum or buzz. Just snow.
The fact that I had near zero noise in the afternoon leads me to believe my house does not contain the source of this noise. My computer and TV were on at the time and it was still rather quiet. Only once the band opened up did the noise come in. What else can I try? Can I rule out my house or neighbors as the source of noise?
EDIT: Link to sound of the noise https://streamable.com/uiyd4