Frequency modulation systems

Claim 1

FREQUENCY MODULATION ARRANGEMENT FOR FREQUENCY MODULATING, ACCORDING TO A PREDETERMINED WAVEFORM, AN ELECTRONICALLY TUNABLE TUBE INCLUDING A FIRST AND A SECOND CONTROL ELECTRODE, COMPRISING IN COMBINATION; A GENERATOR FOR GENERATING A VOLTAGE VARYING PERIODICALLY FROM A MAXIMUM TO A MINIMUM AND VICE-VERSA AND ATTAINING SAID MAXIMUM AND MINIMUM AT PREDETERMINED AND CYCLICALLY REPEATED TIMES; A FIRST MODULATOR CONNECTED TO SAID GENERATOR AND FIRST ELECTRODE FOR APPLYING SAID VOLTAGE TO SAID FIRST ELECTRODE; A SECOND MODULATOR CONNECTED TO SAID GENERATOR FOR GENERATING A FREQUENCY MODULATED WAVE WHOSE FREQUENCY VARIES IN SYNCHRONISM WITH SAID VOLTAGE; AN OUTPUT ELEMENT IN SAID TUBE, A MIXER HAVING A FIRST INPUT CONNECTED TO SAID OUTPUT ELEMENT, A SECOND INPUT CONNECTED TO SAID SECOND MODULATOR, AND AN OUTPUT; A DISCRIMINATOR CONNECTED TO SAID OUTPUT FOR GENERATING A CONTROL VOLTAGE; AND MEANS SERIES CONNECTED BETWEEN SAID FIRST MODULATOR AND SAID SECOND CONTROL ELECTRODE TO APPLY A VOLTAGE TO THE LATTER, SAID MEANS BEING FURTHER CONNECTED TO SAID DISCRIMINATOR FOR RECEIVING AND BEING CONTROLLED BY SAID CONTROL VOLTAGE.