When I work FT8, at times the spectrum display shows a spaced signal.  I am close to the golf course cart path and occasionally get ignition spikes from golf carts.  But, these are different.  I suspect some kind of "splash" from overmodulation somewhere in the nearby spectrum but I have not been able to identify it, or even verify that it is a received signal or an intermod.  I took some snippets and wonder if any of you have seen similar.  Both 15M and 20M spectrum.

Of course, the wider lines are FT8 signals.  I am referring to the narrow and evenly spaced signals.

Thanks, Steve Roth   AD4K   Villa Berea, Polo Ridge