[Lowfer] VLF grabber from last night?

[jrusgrove at comcast.net]

VLF enthusiasts

Anyone have an overnight spectrogram from last night including the 18 kHz 
frequency range? Particularly interested in what periods of time 18 kHz Tacamo 
(?) was active. Only have a brief look at it here on a 'short term' grabber I 
was running  http://www.w1vd.com/grabber.html .

Any info appreciated.

Jay W1VD  WD2XNS  WE2XGR/2