what frequency did he use in these videos ?
https://www.youtube.com/watch?v=Y0jpeN4ROnE&t=2454s
https://www.youtube.com/watch?v=6n5v6XqO6O4&t=1839s
https://www.youtube.com/watch?v=Y0jpeN4ROnE&t=2454s
https://www.youtube.com/watch?v=6n5v6XqO6O4&t=1839s
