US1652516A - Radio transmitting system - Google Patents

Description

Dec. 13, 1927. 1,652,516

F. CONRAD RADI O TRANSMITTING SYSTEM Filed. Dec. 2.5. 1924 INVENTOR ATTORNEY Patented Dec. 13, 1927.

ream; oo RAnfFor' massages; rENNsYL-VAN A, AssiGNoit T 'wnsrmenousn fntn'o'rnrc' a MANUFACTURINGCOMPANY, A consensus-abs PENNSYLVANIA.

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ii A p pii cationIfiI'ed- December 23, 1924. "Seria1' I iIoQ75 Z581i Myinvention relates' to radio signalling systems, and particularly ,toa. construction i .for a "power: connection between. an oscillation radiator and an oscillation generator.

degree of couplingbetween airoscillation generator and an Oscillation radiator.

' Anotherobject of'my invention is toprovide a connecting devi'ce that is adapted, to prevent the transfer of oscillatory energy at frequencies higher than quency.

ZAnOther object In the prior constructionof radio-send in'gapparatus, it has been common-to construct 'an oscillation radiator comprisingan N antenna and a counterpoise with a connecto .the h gher harmon c frequenclestion therebetween, in which may be provided a coiled inductance. It has also been customary to construct an oscillation generator in which triodes and suit-ably connected inductances, capacitances and power sources cause the development of radio frequency oscillations. It has been customary further to position the coiled inductance, in the C11- cuit connecting the antenna and counterpoise,' in inductive relation to the inductance comprisinga portion of the oscillation generator, thus obtaining-a transfer of energy therebetween by means of magnetic coupling. This construction has been foundob-c jectionable because of the necessity either of bringing a portion of the radiator circuit withinthe building housing the oscillation generator, or of mounting the inductance ofthe oscillation generator at a positionwitlr' out the housing structure in order to obtain 'the necessary magneticcoupling.

In my previously filed appllcatlon, Serial No. 666,703, filed Oct. 5, 1924, and assigned to the Westinghouse Electric and'Manuf acturing Company, I disclose a construction for a radio sending apparatus in which an antenna and counterpoise are provided, connected by an inductance and energized by an oscillation generator of the usual type, connection therebetween being made by a conductor and an interposed variable con-'- denser. The resent construction contaming the capacitive connection has been found the, fundamental freof my invention is to pro: vide' means for reducing the current ,value a required to .transmit a givenkamount of ,en- -i, 4 ergy from j an oscillation generator to an OS A cillation radiator. i

types which advantages are listed in that'dis- N one of the p'reviouslyutilized radiosend- "An object of .my inventionis to provide a radio signalling device forcontrolling the ing systems, however, provide satisfactory stopping means for preventing the transfer of osc llat on harmon cs higher than the fundamental oscillation frequency to the anthe system of my previously mentioned disclosure. It is known that the impedance of a condenser varies inversely as the he 7 quency, and that the impedance of an inductance varies, directly as 3 the frequency.

Because of thisfactpthe inductance, when 7 adjusted to interposethe same impedance to the fundamental frequency of oscillation as would beinterposed by a condenser similarly placed, nterposes amuch higher mpedance By reason of thischaracteristic, a much purer frequency is supplied to, and radiated from, the open oscillating system.

' Other objects and structural details of my invention will be apparentfrom the follow- 1 mg description when read in connection with the accompanying drawing, wherein:

The single figure 1s a diagrammatic representation of an embodiment of my invention.

- on the inductance 8 and, a point upon conductor 3 other than the electrical mid-point of the radiator system by a transfer conductor 12, a. portionof which comprises a coiled inductance 14. j i

In the operation of my device, the open oscillating circuit comprising the antenna 1, counterpoise 2, and the inter-connected circuit apparatus 3, 4 and 5, may be tuned to the desired frequency by adjustment of the inductance 4;. Likewise, the oscillation generator 6 may be adjusted to substantially the same frequency by adjustment of the contact llU points upon inductance 8. This adjustment mits the transfer of the only desired amount of energy to the radiating circuit at the fundan'lcntal :trequency and restricts, very strongly, the transfer of energy at higher frequencies, such as the higher harmonics, thereby resulting in a very desirable purity ol radiation frequency.

It has further been found that the energy transfer between the generator device and the radiation device takes place by means of alternating electric currents at substantially zero phase displacement passing throughthe conductor 12 and the inductance 14-. Thus it is possible to make the conductor 12 and iiuluctance l -l oi much smaller size than would otherwise he required.

\Vhile I have shown only oneembtnliment of my invention in the accompanying drawings, it is capable of various changes and modifications therefrom Without departing from the spirit thereof, and it is desired,

therefore, that only such limitations shall be placed thereon as are imposed by the prior art or indicated in the appended claims.

I claim as my invention:

1. In combination, a radiating circuit, an

oscillation generator and a connection between them, the oscillation generator includ ing a closed tuned circuit and means for maintaining oscillations therein and the connection extending from a point in said closed circuit to an intern'iediate point in said radiating circuit near but not at the mid-point thereof and including an inductive reactance.

2. In combination, an oscillation generator including a closed tuned circuit determining the frequency of the oscillations and a vacuum tube device cooperating with said circuit to maintain said oscillations, a radiating circuit comprising open capacitiveelements and a connecting inductive element as- SULlZllGtl therewith to form an electrically oscillating system having the same frequencyas said closed tuned circuit, a connection i'rom said closed circuit to a point near a voltage node of said radiating circuit wherey by the connection may be of small size and a device in said connection for preventing the transfer oi energy or harmonic direquency. i

.In testimony whereof, I have hereunto suhscribed my name this. 113th day of December,

FRANK CONRAD.

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