>>11017192>>11017501anon you can also use a "ground antenna" to hear the VLF band it can be better that an "air" antenna, tesla's system is based on two principals: very high voltage discharge at very low frequencies (the discharge produces a radio wave in the VLF band) .
read his patent, it is all in there, all this is directly related to his estudies on lighting. some pointers:
https://patentimages.storage.googleapis.com/62/90/92/45a5932052a940/US645576.pdf>current impulses of the character described it becomes possible to transmit through easily accessible and only moderately rarefied strata of the atmosphere electrical energy>gases are known to be still nearly perfect insulators for ordinary electromotive forces, they behave toward electromotive impulses of several millions of volts like excellent conductors>for if the voltage be sufficiently high and if the terminals of the coils be maintained at the proper altitudes the action described will take place, and a current will be transmitted through the elevated air strata (rarefied atmosphere), which will encounter little and possibly even less resistance than if conveyed through a copper wire of a practicable size. >"With waves 300 meters in length ( 1Mhz ) economic transmission of energy is out of the question, the loss being too great. When using wave-lengths of 6,000 meters ( 50KHz ) it is still noticeable though not a serious drawback. With wave-lengths of 12,000 meters (25KHz) it becomes quite insignificant and on this fortunate fact rests the future of wireless transmission of energy." the VLF band has great propagation and can even penetrate ground and water this is why is also called "ground wave"
https://www.youtube.com/watch?v=jHK7kKsVVw0https://www.youtube.com/watch?v=L2W1x6Rb9hIhttps://www.youtube.com/watch?v=OzWBxt_TOWk 
