Regarding earth probe antennas, there is a Facebook page dedicated to them at <https://www.facebook.com/groups/earthprobes/>.?
Another link on the page at <https://www.rtl-sdr.com/building-an-underground-earth-probe-antenna-for-0-14-mhz-tx-rx/> references a 1935 article about a buried antenna for SWL.
A search for "buried antenna" gives numerous links and eventually I found links for Soviet and US military documents related to underground antennas used in Cold War communications systems.
I'm more inclined to the simple "LOG- Loop On Ground" concept.
73, Doug Reed, N0NAS.
