Zenneck waves:
https://hackaday.com/2019/11/20/texas-tesla-tower-titillates/&ved=2ahUKEwi_3b2-h-DqAhUHXK0KHbJoAZkQtwIwAnoECAcQAQ&usg=AOvVaw3Rq7E-89jbgJ9jcw0_KMRM&cshid=1595393602710
bbb