40M pulsing spark gap lijke QRN every night continuing until daylight

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40M pulsing spark gap like QRN every night continuing until daylight
K3FEF websdr-wide-spectrum-sparkgap-like-moving. sig.png
Frequencies 7.1 MHz
Frequency Range 7.1 MHz - 7.1 MHz
Mode USB
Modulation unknown
Bandwidth 200 kHz
Location TX, PA, GA, FL, and others
Short Description 40M pulsing spark gap like QRN
I/Q Raw Recording Download file
Audio Sample

These signals have been heard on 40M amateur band as well as on 60M in particular at or about 5600kHz. This QRN is severely limiting effective communications whenever and wherever it is occurring. It starts not long after dusk, and seems to gain strength as propagation improves. It changes from the CWContinuous Wave to Phone portion of 40M. It will last for several minutes and then sometimes disappear for hours. Then it will just randomly start up again. I have 40 plus years communications experience, and I know it is being propagated. At times it is subject to fading, but seemingly it has high power and will usually have a significant signal strength of s9+. My receive conditions are modest. Using FT-897 with 250ft EFHW up 35 ft. Other hams have heard it simultaneously with me in QSOs across the USA.

Where is this coming from and what is it. Is it related to the OTHR sites located in Texas? It doesnt have the swishing CODAR sound, just sounds like a spark gap!