US1473719A - Radiotelegraphy - Google Patents

Description

Nov. 13 3923.; I

I R. R. BEAL RADI OTELBGRAPHY Filed Feb. 19 1920 I IIHIUW INVENTOR nmww Patented Nov. id, 1923.

RALPH R. BEAL, OF PALO ALTO, CALIFORNIA, ASSIGNOR TO AUGUSTUS TAYLOR, OF

SAN FRANCISCO, CALIFORNIA.

RADIQTELEGRAPHY.

Application filed February 19, 1920.

The invention relates to radio telegraphy and particularly to radio telegraphy signaling systems.

An'object of the invention is to provide a systemof single Wave radio signaling, in

which waves having a frequency above the limit of audibility are converted into signals having a frequency within the range of audibility. Continuous radio oscillation gene r ators, such as the Poulsen arc generator, for instance, produce continuous waves having a frequency above the range of audibility but many receiving stations. are not equipped to receive andidentify waves of such frequency. This invention, therefore, contemplates so manipulating the high frequency waves, that signals will be received by such stations and this is preferably accomplished by converting the continuous waves into wave trains or wave groups, the frequency of the groups being within the range of audibility, so that signals so transmitted are readily received and identified by all receiving stations.

The invention further contemplates the use of waves of a single wave length, eliminating the compensating wave. Thus, when the signaling key is depressed, a plurality of groups of waves of a single frequency are radiated and when the key is released, practically no radiation occursl The invention possesses other advantageous features, some of which, with the foregoing, will be set forth atlength in the following description where I shall outline in full, thatv form of the invention which I have selected for illustration in the accompanying drawing, forming part of the pres ent specification. In said drawing I have shown one form of signaling system of my invention, but it is to be understood that I do not limit myself to such form, since the invention, as set forth in the claims, may be embodiedin a plurality of forms.

The drawing is a diagrammatic representation of one form of system of my invention.

Serial No. 360,000.

The system shown comprises a source of continuous oscillations, such as the are 2, which operates in a hydrogen atmosphere. The are generator is grounded on one side, preferably the negative, and is connected on the other side to the antenna 3 through the variable inductance 4-. Direct current is supplied to the arc generator by the generator 5, and a choke coil 6 is arranged in the positive lead to prevent the iiow of radio frequency current to the direct current generator. The are is subjected to a strong transverse magnetic field, produced by the magnets 7 which are preferably separately excited by the dire-ct current generator 8.

Means are provided for varying the electrical constants of the antenna circuit, so

' that the current therein may be reduced be low signaling value. Connected across several of the lower turns of the inductance at is circuit 9 containing an energy consuming element and signaling means for controlling the energy losses in such element. The energy consuming element comprises a core 12, formed of stiff iron laminations, which are so chosen to provide a large hys teresis loss, especially at high frequencies. A coil 13 forming part of the circuit 9 is wound on a portion of the core 12 and the current in the coil produces a flux in the core which causes a loss of energy due to hysteresis. This loss varies the electrical. constants of the antenna circuit, by etieo tively increasii'lg the resistance of the antenna circuit to such value that the current therein is reduced below signaling value. By reducing the hysteresis, the losses are reduced and the effective resistance of the antenna circuit reduced, thus increasing the antenna current to signaling value. This loss is reduced by subjecting the core to a rnagnetomotive force produced by a coil 14 wound on a portion of the core and arrangel in circuit with an alternating current generator 15, the frequency of the generator being within the range of audibility. for instance. 500 cycles. A signaling key 16 is arranged in the circuit of the generator 15 and choke coils 17 are preferably arranged between the alternator and the coil 14:, to prevent the high frequency current generated in the coil from passing to the alternator. The size of the coil 14 and the alternator are preferably such that when the k y is closed, the core is saturated, at intervals depending upon the alternator frequency thereby reducing hysein St; in "fcilt a "cwter s 10 s the en Li t such he quency. lVhen the key is closed, groups of radio frequency Waves are radiated from the antenna, the group frequency being the frequency of the alternator and the groups are separated by periods of practically no radiation.

I claim: 7 V.

1. In a radio transmission system, a source of oscillations, a transmitting circuit connected to the source, a magnetic core, means connected to the transmitting circuit for impressing on said core a flux in accordance with the current supplied to the transmitting circuit, and means for substantially varying the core losses in the core, whereby signaling maybe accomplished, comprising means for impressing on said core an audio frequency flux. 7

2. ,In a radio transmission system, a source of oscillations, a transmitting circuit including an inductance connected to the source, a magnetic core, a winding on said core connected to the transmitting circuit inductance, and means for varying the core losses .in said core to a substantial degree, comprising means for superimposing an audio frequency flux on the core.

3. A radio telegraphy signaling system comprising means .for generating a continuous oscillatory current of undamped radio oscillations, an antenna circuit connected to said means, a signaling circuit, a keyin said circuit, means in the signaling circuit operative to permit radiation from the antenna circuit only when the key is closed and means in the signalingcircuit for dividing the radiated Waves into spaced groups.

i. A radio telegraphy signaling system,

comprising a source of continuous radio oscillations, an antenna circuit connected to circuit, a circuit shunting a portion of'said inductance, means in the shunt vcircuit for producing hysteresis losses, and means for varying said losses at audio frequen y.

In testimony whereof, I have hereunto set my hand at iPalo vAlto, California, this 11th day of February, .1920.

RALPH R. BEAL.

In presence of V MARTHA A. LUNSFQRD.

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