Brian Pease's site at http://radiolocation.tripod.com/ has a lot about building and using equipment for this application. He says "Horizontal range is on the order of several thousand feet and a de
CREG members use loop-to-loop induction systems for determining underground locations (particularly for establishing when the surface station is vertically above the underground one). The transmitter
If I've asked this before please forgive me.... With all the discussion recently on how to radiate a signal on sub-9kHz I'm left wondrering how far, practically, one could expect to get simply with s
