Discussion in 'Amplitude Modulation' started by W0RIO, May 7, 2019.
I did some research on it and came across quite a bit of information.
Interesting reading indeed.
As did I but it wasn't explained in the equipment literature.
This paper https://arxiv.org/pdf/physics/0606109.pdf
seems to indicate that "Quasi-electrostatic " implies treating the AC as if it were DC in a specific domain or in a specific instant in time.
That contraption can't possibly work. There's no 9:1 balun and there isn't even a microprocessor.
That is the same conclusion I had gotten from other sources.
Rather interesting once you get into the tech of it. It basically uses the magnetic near-field for communications in leu of the more commonly used electromagnetic far-field radiation. The reasoning for using such a low operating frequency is that the effective range is only within one wavelength of the antenna.
My colleagues and I tend to think this term is kinda nutty.
A system is either Dynamical, i.e. changing or moving, or it is static, no change-no movement.
I guess the term, while somewhat impressive but imprecise, is simply a shorter term than stating:
"a physical system where the effects of charges and currents do not extend to spatial infinity but have short-range boundary conditions."
This VLF equipment does make sense for spelunking since cave walls will act as ducting for those long-waves.
Of course, back in 1960, Harold Wheeler suggested "Crustal Communications" via 1.5 kHz RF waves.