Transistor underwater telephone system

Claim 1

A HELICOPER-BORNE UNDERWATER TELEPHONE SYSTEM WHEREIN A TRANDUCER IS CARRIED UNDER WATER ON A CABLE EXTENDING FROM THE HELICOPER, SAID SYSTEM COMPRISING: A TRANSMITTER-RECEIVER CONTAINED IN SAID HELICOPER; A TRANSDUCER MEANS FOR TRANSMITTING AN ACOUSTIC SIGNAL IN A WATER-TANSMISSIVE FREQUENCY BAND IN RESPONSE TO AN ELECTRICAL SIGNAL IN SAID BAND FROM SAID TRANSMITTER-RECEIVER AND FOR PASSING TO SAID TRANSMITTERRECEIVER AN ELETRCIAL SIGNAL IN SAID BAND IN RESPONSE TO A RECEIVED ACOUSTIC SIGNAL IN SAID BAND; SAID TRANSMITTER-RECEIVER COMPRISING: MEANS FOR PROVIDING A CARRIER FREQUENCY WHICH IS THE DIFFERENCE BETWEEN SAID WATER TRANSMISSIVE FREQUENCY BAND AND A COMMON TELEPHONE PASS BAND; FIRST MEANS FOR RECEIVING AN ELECTRICAL SIGNAL IN THE TELEPHONE AND CONVERTING IT TO AN ACOUSTIC SIGNAL IN THE TELEPHONE BAND; SECOND MEANS FOR RECEIVING AN ACOUSTIC SIGNAL IN THE TELEPHONE BAND AND CONVERTING IT TO AN ELECTRICAL SIGNAL IN THE TELEPHONE BAND; MODULATOR-DEMODULATOR MEANS FOR ADDING SAID CARRIER FREQUENCY TO SAID ELECTRICAL SIGNAL FROM SAID SECOND MEANS AND PASSING IT TO SAID TRANSDUCER AND FOR SUBTRACTING SAID CARRIER FREQUENCY FROM SAID ELECTRICAL SIGNAL RECEIVED FROM SAID TRANSDUCER AND PASSING IT TO SAID FIRST MEANS; REACTIVE MEANS IN SAID HELICOPTER BETWEEN SAID TRANSMITTER-RECEIVER AND SAID TRANSDUCER FOR CAUSING SAID TRANSDUCER TO BE RESONANT AT THE CENTER OF SAID WATER TRANSMISSIVE FREQUENCY BAND; A TRANSMITTER AMPLIFIER FOR PASSING AN ELECTRICAL SIGNAL FROM SAID MODULATOR TO SAID TRANSDUCER AFTER INCREASING THE POWER LEVEL OF SAID SIGNAL; SAID TRANSMITTER AMPLIFIER COMPRISING: A FIRST TRANSFORMER; TRANSISTOR AMPLIFIER MEANS FOR BOOSTING SAID SIGNAL FROM SAID MODULATOR AND PASSING IT TO SAID FIRST TRANSFORMER; A PAIR OF TRANSISTORS HAVING A FIRST SET COMMON ENDS JOINED TOGETHER TO A VOLTAGE SUPPLY, SAID FIRST TRANSFORMER BEING JOINED TO THE BASES OF SAID PAIR OF TRANSISTORS; A SECON TRANSFORMER, SAID SECOND TRANSFORMER BEING CONNECTED TO A SECOND SET OF COMMON ENDS OF SAID TRANSISTORS; A TWO-WAY VOLTAGE LIMITING MEANS CONNECTED IN PARALLEL WITH SAID SECOND TRANSFORMER ACROSS SAID SECOND SET OF COMMON ENDS OF SAID TRANSISTORS SAID FIRST TRANSFORMER BEING CENTER TAPPED TO A VOLTAGE SUPPLY; A RECEIVER AMPLIFIER FOR RECEIVING A SIGNAL FROM SAID REACTIVE MEANS AND SAID TRANSDUCER AND BOOSTING IT AND PASSING IT TO SAID DEMODULATOR, SAID RECEIVER AMPLIFIER COMPRISING: A PAIR OF TRANSISTOR AMPLIFIER STAGES FOR RECEIVING A PAIR OF ELECTRICAL SIGNALS FROM SAID TRANSDUCER 180* OUT OF PHASE WITH EACH OTHER, ONE OF SAID TRANSISTOR AMPLIFIER STAGES HAVING TWO TRANISTORS IN SERIES FOR REVERSING THE PHASE OF SAID SIGNAL 360* AND THE OTHER TRANSSISTOR AMPLIFIER HAVING ONE TRANSISTOR STAGE FOR REVERSING THE PHASE OF SAID SIGNAL 180* SO AS TO BE IN PHASE WITH THE OTHER OF SAID SIGNALS; MEANS FOR PASSING THE SIGNALS FROM BOTH SAID AMPLIFIER STAGES TO A THIRD AMPLIFIER STAGE; A THIR TRANSFORMER; MEANS FOR APPLYING THE SIGNAL FROM SAID THIRD AMPLIFIER STAGE TO SAID THIRD TRANSFORMER; A PAIR OF TRANSISTOR AMPLIFIERS HAVINFG A FIRST SET OF COMMON ENDS JOINED TOGETHER TO A VOLATAGE SUPPLY, THE BASES OF SAID PAIR OF TRANSISTORS BEING JOINED TO SAID THIRD TRANSFORMER; A FOURTH TRANSFORMER, A SECOND SET OF COMMON ENDS OF SAID PAIR OF TRANSISTORS BEING JOINED TO SAID FOURTH TRANSFORMER, SAID TRANSFORMER BEING CENTER TAPPED TO GROUND AND HAVING MEANS TO PASS A SIGNAL TO SAID DEMODULATOR; AND A TWO-WAY VOLTAGE LIMITING MEANS CONNECTED IN PARALLEL WITH SAID FOURTH TRANSFORMER ACROSS SAID SECOND SET OF COMMON ENDS OF SAIS TRANSISTORS.