12 Mar 2017
Casual listening will not bring results: long stable transmissions are needed together with very stable, narrowband reception if amateur VLF/ULF signals are to be detected. Commercial VLF signals on the other hand are very strong as most use high power and big antennas.
The photo shows DF6NM's loading coil for 5.17kHz today.
See https://sites.google.com/site/sub9khz/ .