This signal has been present in the early morning and late evenings for the last couple of months, that I know of. I am receiving these in the north Texas region.
It appears to be 25 - 40 Hz wide. There is a red circle drawn around a notch filter in the first image, that filter is 25 Hz wide.
The signal lasts roughly 120 seconds. Sometimes they are ten minutes apart, but not consistently.
I am sure this is simple for someone who knows digital signals.
Thanks for taking a look!
