Transmitter for radio-sonde battery potential indications

Claim 1

IN A RADIO SONDE HAVING A TRANSMITTER INCLUDING AN OSCILLATOR HAVING A MODULATION CIRCUIT, AND A BATTERY, A BATTERY POTENTIAL INDICATOR COMPRISING A MULTIVIBRATOR INCLUDING A PAIR OF HOT CATHODE TRIODE TUBES, A SOURCE OF PLATE POTENTIAL FOR SAID TUBES, SAID SOURCE INCLUDING A PLATE BATTERY, AN IMPEDANCE AND A GASEOUS DISCHARGE DEVICE CONNECTED IN SERIES CIRCUIT RELATION ACROSS SAID PLATE BATTERY, SAID DISCHARGE DEVICE HAVING A SUBSTANTIALLY CONSTANT ANODE TO CATHODE POTENTIAL OVER A WIDE RANGE OF APPLIED POTENTIALS, CONNECTIONS APPLYING THE POTENTIAL OF SAID DEVICE TO SAID MULTIVIBRATOR, SAID BATTERY CONNECTED TO SUPPLY THE HEATING CURRENT OF THE CATHODES OF SAID MULTIVIBRATOR, A RESISTOR CONNECTED IN SERIES CIRCUIT RELATION BETWEEN SAID BATTERY AND SAID MULTIVIBRATOR, SAID RESISTOR DROPPING THE APPLIED POTENTIAL TO SUCH A POINT THAT THE MULTIVIBRATOR, IS SENSITIVE TO VARIATIONS IN CATHODE POTENTIAL WHEREBY VARIATIONS IN BATTERY POTENTIAL VARY THE FREQUENCY OF SAID MULTIVIBRATOR, AND CONNECTIONS IMPRESSING THE VARIABLE FREQUENCY OF SAID MULTIVIBRATOR ON SAID MODULATION CIRCUIT