Which of the following filters is used in a 2-meter band repeater duplexer?
A crystal filter
A cavity filter✓Respuesta correcta
A DSP filter
An L-C filter
Explicación
A 2-meter repeater duplexer must give tens of decibels of isolation between transmit and receive frequencies only 600 kHz apart while handling full transmitter power. Only resonant cavities have both the Q and the power handling for that job.