TWO-WAY RADIO WITH IMPROVED SQUELCH

• Main Authors: CHEAH CHOW LOONG, LEE SIEW YIN
• Format: Patent
• Language: English
• Published: 29.07.2005

A TWO-WAY RADIO (1) THAT HAS A RADIO FREQUENCY RECEIVER (2) HAVING A MODULATED RADIO FREQUENCY SIGNAL OUTPUT AND A VARIABLE BANDWIDTH FILTER (3) WITH AN INPUT COUPLED TO THE MODULATED RADIO FREQUENCY SIGNAL OUTPUT. THE RADIO (1) ALSO HAS DEMODULATOR CIRCUITRY (4), A SPEAKER (6) AND PROCESSING CIRCUITRY (5). IN USE WHEN THE RADIO (1) IS OPERATING IN SQUELCH MODE, THE PROCESSING CIRCUITRY (5) CONTROLS THE VARIABLE BANDWIDTH FILTER (3) TO HAVE A FIRST BANDWIDTH AND WHEN IN UNSQUELCH MODE THE PROCESSING CIRCUITRY (5) CONTROLS THE VARIABLE BANDWIDTH FILTER (3) TO HAVE A SECOND BANDWIDTH WHICH HAS A SMALLER FREQUENCY RANGE AND THE FIRST BANDWIDTH.FIG. 1