Agraz
Tenderfoot
Thortech was a company that sold devices to locate treasures, this supposedly used CB radios to locate treasures, I think it is difficult because of the high frequency of the radios, I do not believe that the waves penetrate the earth ...
https://pe2bz.philpem.me.uk/Detect-Sense/- Alternative/- Dowsing/thor-ldt.html
https://pe2bz.philpem.me.uk/Detect-Sense/- Alternative/- Dowsing/thor-ldr.html
https://pe2bz.philpem.me.uk/Detect-Sense/- Alternative/- Dowsing/thor-ldt.html
https://pe2bz.philpem.me.uk/Detect-Sense/- Alternative/- Dowsing/thor-ldr.html