This animated gif image was created from a realtime recording of the first two resonances. The receiver had a steep rolloff lowpass filter which degrades the strength of the second resonance. This is evident in the image. The vertical red markers are placed at 8hz. and 14hz. There was also a storm approaching which may have influenced the surge in intensity of SR as seen periodically in the gif.

Various Schumann Charts Using Induction Coil And A Lowpass Frequency Cutoff Of 18hz.

Various Schumann Charts Using A Floating Receiver/Stylus.

The image below was recorded in Italy. VLF-it.