Underwater communication system

Claim 1

A COMMUNICATION SYSTEM FOR A STATION DISPOSED IN A CONDUCTIVE MEDIUM, SAID SYSTEM INCLUDING A RECEIVER CIRCUIT COMPRISING: AN IMPEDANCE MATCHING INPUT TRANSFORMER HAVING AN INPUT WINDING AND AN OUTPUT WINDING, SAID INPUT TRANSFORMER HAVING AN IMPEDANCE RATIO OF MORE THAN 1 TO 1000 AND HAVING SAID INPUT WINDING ADAPTED TO BE CONNECTED TO A PAIR OF SPACED PROBES DISPOSED IN THE CONDUCTIVE MEDIUM; A FIRST CAPACITOR CONNECTED ACROSS SAID OUTPUT WINDING, FOR DISSIPATING SIGNALS OF HIGHER THAN AUDIO FREQUENCY WHEREBY BROADCAST SIGNALS AND THE LIKE ARE GENERALLY DISSIPATED; A FIRST TRANSISTOR AMPLIFIER STAGE INCLUDING A FIRST TRANSISTOR CONNECTED IN A FIRST COMMON EMITTER AMPLIFYING CIRCUIT HAVING A BASE-EMITTER INPUT AND A COLLECTOE-EMITTER OUTPUT, SAID FIRST TRANSISTOR HAVING A FLOATING, NON-DIRECT CURRENT BIASED BASE WHEREBY INPUT SIGNALS TO SAID BASE OF SAID FIRST TRANSISTOR ARE NOT LOADED DOWN BY A BIAS RESISTOR; A SECOND CAPACITOR CONNECTED IN SERIES BETWEEN ONE SIDE OF SAID OUTPUT WINDING AND SAID BASE OF SAID FIRST TRANSISTOR, THE OTHER SIDE OF SAID OUTPUT WINDING BEING CONNECTED TO SAID EMITTER OF SAID FIRST TRANSISTOR WHEREBY THE HIGH IMPEDANCE SIDE OF SAID INPUT TRANSFORMER IS CONNECTED TO SAID BASE-EMITTER INPUT OF