APRS signal considerations

• In order for iGates and digipeaters to successfully decode your packet, the packet must be transmitted in a way that is understandable.
• Be careful to not overmodulate your signal.
• Pre-emphasis is normally good for FM voice communications, but can distort the APRS waveform by increasing the amplitude of one of the AFSK tones.
• Too little TX lead and tail times (padding before and after the packet) can prevent clock synchronization at the receiver, resulting in missed packets.

A pre-emphasized AFSK signal