Frequency range:640-690MHz Modulation: Broadband FM Adjustable range:50MHZ Number of channels:250KHz Frequency stability:± 0.005% or less Dynamic range:100dB Maximum frequency deviation: 45KHz Audio response:80Hz-18KHz( 3dB) Integrated messenger ratio:> 105dB Integrated distortion:≤0.5% Operating temperature:-10℃-+40℃