Jerry, this is not an issue with a receiver being too wide or something like that, this is a real signal that has been being seen frequently for the last couple months. It has been seen in both 40 meters and in 30 meters, but it is almost certainly not a ham signal.
The signal is not on all the time, it just shows up every once in a while for a short period and then disappears. It has been discussed on the UDXF mailing list and been heard all across the US and Europe.
Here is a video of it in the 40 meter band last month.
https://www.youtube.com/watch?v=mSP8pHtqOd4
T!