The higher the frequency the shorter the wavelength and the shorter the transmission range. (for a given transmission power) Velocity=Frequency x Wavelength. Velocity is the speed of light, 2.98x10exp8 frequency is (FM radio is 87.5 to 108.0 MHz) so you can work out the wavelength and the ideal antenna length.
FM radio for a 25 kW transmitter will travel about 100klm line of sight only ( will not skip over mountains) TV is higher freq still and has shorter range.
Medium wave and Short wave radio use Amplitude Modulation which travels further but is poor quality sound. To date the only way to get TV quality signals long distance is by Satellite or stream over fibre optic cable
