>>9508671the "spark tansmission" is very simple and straight foward , it does work, but his idea of imparting the earth a super high voltage standing wave in the VLF range... I'm not so sure about this, one big problem for testing this idea to the fullest is that you'll need super long antennas (miles long) and big coils to get the maximum efficiency, tesla is very explicit about this (he's correct) but he talks of miles long antennas like if there were no practical problems with that...
page4, parag.5: the location of the apparatus must be determined whit reference to the position of the stationary waves established by the generator, the effect evidently being greatest in a maximum(peak of the wave) and Zero in a nodal region. On the other hand, if both plates be connected to earth (this are called "ground antennas" in HAM radio) the points of connection must be selected with reference to the potential which it is desired to secure, the strongest effect being of course obtained when the plates are at a distance equal to half the wave length
https://teslauniverse.com/nikola-tesla/patents/us-patent-787412-art-transmitting-electrical-energy-through-natural-mediumshttps://patentimages.storage.googleapis.com/b1/33/9f/315209c5549a8c/US787412.pdf this means that for example for 25Khz we'll need a 6km (3.7 miles) long antenna! to get the maximum efficiency and also notice that theres goin to be places with very low energy because those are the null point of the standing "wave"
this gif illustartes a standing wave were you can see how the null points (in blue) have no energy (no voltage swing present in that location) the biggest voltage swing will be if you put "ground plates" to pick up the voltage swing between two red points.
the lower in frequency we go the better but the antennas/coils become even larger. 25Khz to 35Khz is the top range of the VLF band.
