Power Tower Q: What wavelength and frequency range do you use for Power Tower?

We are in designated civilian use zone up to 10 kHz in many countries including USA, Russia, Canada, UK, and others. Most countries allow use for civilian purpose from 3 to 14 kHz and are unallocated below 9 kHz. Wavelength depends on the particular frequency. For 10kHz frequency wavelength is equal to 30 000 m (18,6 miles)