[RFI] Identification help

[Dan Zimmerman N3OX]

I have a strange source of very strong interference, especially on
80m, but I've heard it at least on 40m and 17m as well.  I haven't
quite figured out the pattern in frequency where it's worst, but bad
spots are 3512 and 3795 kHz and around there, and it's pretty
irritating.  It's strong enough to cover up s9 signals.

It sounds like a burst of white noise lasting a few seconds but starts
and ends with a little warble.

I have some recordings:

AM mode, AGC off, wide filter, 3795 during the day:
http://www.n3ox.net/files/80m_rfi.mp3

LSB mode, AGC off, 2.4kHz filter, 3595 at night, you can hear the
warble better in this one: http://www.n3ox.net/files/80m_LSB_1.mp3

And I have a spectrum capture of one of the events, somewhere on 80m, LSB:
http://www.n3ox.net/files/80m_RFI_1105.jpg

Anyone know what this one is?

73,
Dan