Operating below 9kHz

Amateur operating below 9kHz is different.

Although earth-mode is a form of VLF operations open to all, radiated amateur radio VLF below 9kHz needs high power, very stable signals (usually locked) and very narrow FFT bins (extremely narrow bandwidths) with very long integration periods (often days) to get anywhere distant. It can be done and signals have crossed the Atlantic.

Do not expect to just listen and hear amateur signals! You will be disappointed. Amateur signals are far weaker than some of the commercial signals that often have huge powers and very big antennas.

As I mentioned, earth-mode, especially utilities assisted can be very successful with low-power and homemade gear.

In recent years keen enthusiasts have used modes like eBNaut with success.