SINGLE CHANNEL AUDIO BRIDGE FOR VOICE INTEGRATION BETWEEN LEGACY RADIO NETWORKS AND TETRA NETWORKS

A SYSTEM FOR CONNECTING AT LEAST ONE LEGACY RADIO NETWORK WITH AT LEAST ONE NETWORK OF FIELD COMMUNICATION RADIO DEVICE IS PROVIDED. THE SYSTEM INCLUDES A FIRST EMI/EMC FILTER (202) THAT FILTERS ANY UNDESIRED HIGH FREQUENCY SIGNAL FROM EITHER OF THE NETWORKS; A FIRST LOW PASS AUDIO FILTER (204) THAT FILTERS ANY UNDESIRED AUDIO SIGNAL; A FIRST VOX/VAD UNIT (206) TO FILTER NOISE AND TRUE VOICE; A MODE ELECTRONIC SWITCH (208) TO SET AT LEAST ONE MODE OF OPERATION AND CHANNEL THE SIGNAL FROM ONE NETWORK TO ANOTHER; A FIRST (PTT) LOGIC MANAGEMENT UNIT (210) MANAGES TRANSMISSION IN EITHER OF THE NETWORKS; A FIRST AUDIO AMPLIFIER (212) AMPLIFIES INCOMING SIGNALS; A SECOND EMI/EMC FILTER (214) THAT FILTERS ANY UNDESIRED HIGH FREQUENCY SIGNAL FROM A NETWORK OTHER THAN THAT WHOSE AUDIO SIGNAL WAS RECEIVED BY THE FIRST EMI/EMC FILTER (214); A SECOND LOW PASS AUDIO FILTER (216); A SECOND VOX/VAD UNIT (218); A SECOND PTT LOGIC MANAGEMENT UNIT (220) AND A SECOND AUDIO AMPLIFIER (222). (MOST ILLUSTRATIVE DIAGRAM: