On 2/11/2025 11:55, Everett N4CY via groups.io wrote:
What would happen if you put two ground rods in the ground, spaced 25' to 50' apart and use an amplifier?
I'd have to dig out some old books, but I think the Germans were doing that, minus the amp at the time, in the 1860's. I seem to recall a section in one of my radio books from around 1906 having a decent writeup on it. It wasn't called radio yet, but was known as wireless at the time, and detected intentional signals, but it was the beginning.
For several decades, probes with amplifiers were the go-to. Probes ranged from screwdrivers stuck in the dirt in gardens, to 1m rods tens of meters apart. Several years ago, I asked about two probes, one about 200' deep, the other, about 500', 1/2 mile apart. No response. I no longer have access to both of those probes. I also had the idea of a 1/2 mile loop, and up to a dozen turns a half mile around each. I may still play with that.
Here is some probe info:
If you can find references to the old ELF/ULF forum that was on Yahoo, it was almost entirely discussing probes.
This one may parallel it:
/g/VLFIf not, people at the above forum may have info.
Kurt
