Hi Markus,

> ...
> The wideband panel at http://www.mydarc.de/df6nm/vlf/vlfgrabber.htm is 
> currently set to the military frequencies above 19 kHz. 
> In addition to NWC (Australia), which has been regularly visible here on 19.8 
> kHz above GBZ, I noticed that there is also a weak strip and corresponding 
> hump on 21.4 kHz from NPM (Hawaii). It seems to be best in the morning hours, 
> especially during the dips of its overwhelming neighbour HWU 21.75 kHz. It's 
> very strong at KL7UK's grabber and also a clear peak on 
> http://abelian.org/vlf/spectrum.shtml in Todmorden.
> 
> NAA 24.0 kHz is often remarkably strong on the samplerate edge,  and at times 
> there is even a weak trace on 22.8 which seems to be an alias of NML 25.2 kHz.
> 
> NDT (Japan 22.2 kHz) has so far escaped my detection attempts, but it may be 
> too difficult due to the proximity of GQD.
> ...

Not bad! Watch 19.2 kHz. Clear visible sunrise effect around 0100 utc.
Should be one of the VTX-frequencies:
http://maps.google.de/maps?ll=8.3845691,77.754468&z=14

Would be interesting what you can "see" up to ~85 kHz and what kind of
antenna/preamp used.

Greetings from Kiel,
Peter