Abstract: A radio signal relaying device has a PDA and a wireless modulating module connected to the PDA. The PDA is provided with multiple ports of different specifications such as a memory card slot, a USB interface or a serial port. The wireless modulating module is selectively linked to one of the ports to modulate music files stored in the PDA. The modulated sound files can be transmitted in the form of radio waves and then be demodulated and played by any radio receiving device.

Abstract: A broadcasting method using a PDA as a signal relay device has the steps of (a) modulating a sound file intended to be broadcast, wherein the sound file stored in a PDA is modulated in the form of a radio wave at a set frequency, (b) transmitting the modulated radio wave, (c) demodulating and (d) playing the radio wave to obtain the sound file by any radio device. A broadcasting apparatus utilizes a modulating module that is integrated into a charging base of the PDA to modulate sound files stored in the PDA. the modulated sound files can be transmitted in the form of a radio wave and then be demodulated and played by any radio receiving device.