On Fri, Mar 26, 2021 at 04:34 PM, Bill Somerville wrote:

...are you sure it is WSPR? FST4W signals can often be found near the WSPR
sub-bands.

73
Bill
G4WJS.

Bill,
I guess I should experiment by shifting the receiver frequency slightly.  They are so close to the WSPR band and with the same width and duration, so I had assumed they were WSPR.
Bruce KX4AZ