Re: VLF: Some natural signals

[Paul Nicholson <vlf0403@abelian.org>]

> Is that recorded with antenna direct into soundcard
> (metaphorically speaking ) ?

Yes.  There's no frequency shift, just amplification of
the audio frequencies present on the E-field probe.

Not even that much amplification, on the order of x50 voltage
gain before the soundcard (which needs 4 volts for full scale).
The only post processing is hum notching, 5 pole high pass
at 300 Hz and 3 pole low pass at 10kHz.

--
Paul Nicholson
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