US1687828A - Wireless-telephone tube sending station - Google Patents

Description

Oct. 16, 1928.

H. .CHIREIX WIRELESS TELEPHONE TUBE SENDING STATION Filed July 23, 1923 AMPLIFIER HFGENERATOR avweutoz $51 Yam, Gum/mug);

NR! CHIRElX Md 4 41M Patented Oct. 16, 1928.

- UNITED STATES HENRI CHIREIX OF PARIS, FRANCE.

wrnELEss-TELEPHoNE TUBE SENDING STATION. i

Application filed July 23, 1923, Serial No. 658,181, and in France October 4, 1922.

The" object of the present invention is to improve the emission obtained by means of tube stations when thesetubes are fed from an alternating current source through the agency of a rectifying means. It happens that, notwithstanding the care taken in rectifying the supply current, this current is not perfectly continuous. Onthe other hand, even if the circuits are very carefully installed, there will always remain a residual electrostatic and electromagnetic induction effect. Finally, due to the fact that the filaments are heated by analternating current, their calorific inertia mustbe taken into consi'deration, and the differences of potential between grid and filament, and plate and filament vary in accordance with the frequency of the supply current. Due to these causes, one or several sounds will be heard at the receiving station, said sounds correspondingto' the frequency of the feeding current and its harmonics. This sound is particularlyannoying in case music or singing is transmitted.

In accordance with the present invention, this tone is suppressed by superimposing on the microphonic potential variations an E. M. F.'which is synchronous with that of the supply source, and the phase and amplitude of which are variable; Obviously, the introduction of this compensating E. M. F. may be effected at any suitablepoint in the. modulating circuit, and by any suitable electrical connection (conductive, inductive, capacitive The invention will be more readily understood from the following description of an exemplification which is schematically illustrated in the figure of the drawings. 1 is the pick-up microphone with its source 2 and coupling transformer 3. 4 is a microphonie current amplifier. 5 is a coupling transformer provided between the transmitter circuit and the modulating circuit of the apparatus generating the continuous waves and schematically illustrated at '6. The system radiating the modulated waves is shown at 7 (antenna). In accordance with the present invention, an M. F. is introduced into the circuit traversed by the transmitter current e. g. at 8 through the agency of a variable coupling transformer shown at 9. This E. M. F. is of the same frequency as that of the alternating current generator which is feeding the tubes of the high frequency generator 6, the phase of the 'E. M. F. being coil- 15 provided in this field may be pointed in the desired direction.

Obviously, the invention may be subjected to numerous variations. In certain cases in which it is desired to suppress also the'efiect of the harmonics of the main tone, as many similar arrangements should be superimposed as there are harmonics to be suppressed. The juxtapositionof these arrangements'will make possible various circuit combinations and simplifications. Harmonic opposing E. M. F.s maybe generated in the supply source by any suitable frequency multiplying means (particularly by means of tube systems arranged to double the frequency). Finally, it should be noted that the above described circuits may be shielded with respect to the considerable induction effects of the high frequencies by providing a casing 16 of conducting material which is suitably grounded} and forms an electrostatic and electromagnetic screen around. the cirwits and apparatus traversed by the 'c'0m-' pe'nsating currents. Furthermore, it is advisable to provide very long insulated knobs for'operating the movable elements (variometer 15, coil 9, etc.), or equivalentdistant controlling means so as to avoid the disturbances in the tuning that may be caused by the approach of the operator,

Having described my invention, what I claim is:

1. The method of eliminating feed frequency tones and harmonics thereof in modulating systems utilizing alternating or rectified currents which consists in deriving from such currents another current and supplying such current to the modulating current in a manner to neutralizethe feedfrequency tones.

2. The method of neutralizing undesired frequency in modulating system utilizing fluctuating currents which consists in deriving from such fluctuating currents a second current, introducing such current into the clrcuit traversed by the .modulatlng current and adjusting the phase of the current so introduced in a manner to neutralize the undesired frequencies.

3. In a radio signalling system, an oscillator, means for modulating the output of said oscillator, means for supplying power to said oscillator, Jeans in shunt with said oscillator for producing -a rotating field, means arranged to have currents induced therein by the action of said field and means for supplying such currents to said modulatin means.

4. In a radio signalling system, a transmission conductor, an oscillator for energizing said conductor, means for modulating the output of said oscillator, a source for supplying power to said oscillator, means actuated by said source for producing a rotating field, means for deriving from such field a secondary current and means for combining such current with the current to be modulated.

5. In radio signalling apparatus, the com bination of a transmission conductor, an oscillator for energizing said conductor, means for modulating the output of said oscillator, a source of power for energizing said oscillator, means associated therewith for producing an alternating current of any desired phase relation with respect to the current delivered by said source, means for combining such current with the modulating current and means for varying the intensity of such current.

6. In radio signalling apparatus, the combination of a transmission conductor, an oscillator for energizing said conductor, means for modulating the output of said oscillator, a source for feeding said oscillator, phase shifting means for producing a current having a desired phase relation wlth the oscillator current and variable coupling means for combining such current with the modulating current. I

7 In a radio system a transmission conductor, means for producing oscillations in said conductor, means for modulating said oscillations with speech currents, means for producing a current in any desired phase relationship to said oscillations and means for combining said last named current with said modulating speech currents.

8. In a radio system, a transmission conductor, an oscillator for producing oscillations therein, means for modulating said oscillations, a source of alternating current energy for supplying power to said oscillator, a circuit connected to said source including means of the same frequency said modulating means to cause a current flow in said modulating means of the same.

frequency as'said source and in any desired phase relationship. r

9. In a radio system an oscillator, a source of low frequency alternating current for feeding said oscillator, means for modulating the output of said oscillatonand means connected with said. source for causing current flow in said modulating means of the same frequency as said source, and in any desired phase relationship.

10. In a radio system an oscillator, a source of low frequency alternating current for feeding said oscillator, means for modulating the output of said oscillator, and means for causing current flow in said modulator of the same frequency as said source, said last named means including means for varying the intensity of said current, and means for varying the phase of said current. V

' V. HENRI CHIREIX.

for producing a rotating field as said source and ad ustable means in said field connected to.

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