>  11dB @ 0.12fT and 278 uHz implies approximately
>  2fT/root-Hz aggregate noise?

That's about right for a quiet night. That's after sferic
blanking - before the blanker the background is some 20dB
or more higher.

The system noise floor is about 0.2 fT RMS in 1Hz.

There happens to be a fairly accurate model of the antenna
and receiver in example 6 of this program

 http://abelian.org/lcnetgen/

which I've been working on for a few months.
LCnetgen may be handy for modelling LF/VLF antennas and coils.

--
Paul Nicholson
http://abelian.org/
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