USRE17163E - District - Google Patents

Description

' A E. E. CLEMENT IO BROADCAST SELECTING AND DISTRIBUTING SYSTE" Original Filed Feb. 29, 1924 saw/1 70 Jun 'i matter;

' thus'supplied from central 1166 ei sue! Dec. 11, 1928.

NITEDSTATE A ENT O FICE- r nnwaan E. animus,

ori inai No. 1,522,360, d ted January 6,

1 reissue flied January My inventionrel'ates to systems for radio "broadcast distribution and hasfor its object o to renderit possible for very simple type of receiving apparatusito Jbe able to select with: certainty and'receive within the range of the present high powered long range receivers, such asthe ,supere l'h y e- It is an object of my inventiontoprovide additiomrl receiving apparatus at the central station adapted to tion for the detection of the signal-modulaline circuitsa type of current which willprove suitable for communication back and forth 'Otherobjects will suificiently appear herein- Y I- attain my by providing each suhscriber tothe system with a receiving 'antenna andvtuned secondary circuit as usual, and I supply each subscriber from a central stathec'arrier current'receivedfrom anypar- 'ticular or desired distant station, 'Inorder to; beable to do this, linstall at a central station a plurality of oscillators tunedto different frequencies, and I'provide theoutor the like, so that nected with the subscribcrs wired lines. In the connectingcircuits, whichmay be ordi- -nary cord circuits w cillator currents,- and since their plate circuits are connected to the, lines theyisup ply the latter with unmodulatedpulsating igh. 1 frequency.

' scribersstation in ,one sideof-either' 9. (iiig-Inone form ofthe invention, th currents the received modulated radio waves to prov I -1duce locally an amplified modulated asym- 1925, Serial no; 695,993, filed February 29,1924. 5, 1-927. Serial mymmsv subscribers with a i with ample power from any distant station.

cooperate with the simple receiving apparatus at the subscriber s stak' tions and at the same time to supply to'the being received in a an ordinary radio telephone receiver, when ''between the subscribersand the operator..

' tion with 1. unmodulated pulsating current at a frequency suitable to heterodynewith' panying rawing i Wh "central connecting c1rcuits for the same, together with oscillators at the central station; Y Figs. 2 and 3 show special put terminals'of theseoscillator-circuits with Y scribers receivers; "proper switching terminals, such as jacks" they can be intercon- 'centr'alstation and S I ith terminal plugs, pro 1 vided] at the central oflice for connecting oscilla'torsto-t esubscribers lines, I pro- Q vide detector tubes, which rectify the ,os-

as plug cordncircuits' A an a A has a plug P and a plugPf. connected: by heterodyningfi currents, These currents are taken in at "thefrsubferential circuit or? ina 'difierential receiver ,andtherein combined-with the. modulated. I radio currentsre'ceived over the antenna fcirbined with Senorita-may take R nate name nnoancasr snnnc'rmo' AND nrs'rnmurme sYs'rnu.

Application 101' imetricbeat wave, which is, capable of being received on anrordinary radio telephone ,re- CGIYBI'. However, various types of local or wasarnemon, manner or commnm, Assmiwoa 'ro EDWARD r. COLLADAY', or wasrmmron, ms'mrc'rqorconumnmu heterodyning circuitsor instruments may he employed, the invention residing particularly in the supply and transmissionffrom the central station of unmodulated oscillator current at diflerent frequencies, toenable the subsomber to make selection by heterodyning without thetrouble of elaborate apparatus or tuning at his substation. An ancillary but yeryl important feature of the'invention isthe furnishing of unmodulated pulsating current for heterodyning whereby the beat 7 wave will be an asymmetric modulatedwave, capable of simple receiver set or in properly connected, w thout further detection, thus obviating the 'rality of detectors atthe subscribers stations.

Furthermore, the type ofcurrentthus supn plied inthe line,circuitsis suitable for communication back and forth between scribers and the operators.

o invention is illustrated the subforms of sub- Referring to the drawing, Fig. C is a is a. subscriberssta:

necessity fora plution. At the former I locate oscillators ,O, n

O, f etc;, having their circuits ,connecte tozs'witching terminals J, J JF, etc, whereby they, may be interconnected with the switching terminals J ofsubscribers lines. The switching terminalsin the drawingsare shown as jacks, and the connecting means 7 d B, The cord s d t r 2,

the input, or gridcircuit of atubesdetectqr D, the plate or output circuit of which s B to line wires 5 -6-leading to the. subscribers station.

connected through the plug 3, 4, 1 and3-constitutijng Sh w in, Fee 2 an -1 R se s 2 r m a tion C sents a type ofFessenden receiver, in which one coil is connected to line, and the other is coupled to the receiving antenna, one of the coils being preferably associated in fixed relation with the diaphragm in the well known manner. In Figure 3 is shown an equivalent; arrangement of coils in which the received waves and those supplied from central are both supplied in the plate circuit of the detector tube extended, instead of being confined in separate circuits as in the Fessenden type receiver shown in Fig. 2. It is a parent that, in either case, with proper ection of oscillator frequency at the central station, the signal is made audible in the subscribers radio receiver without the need scri ers station. I

It is to be understood that it is within the spirit of my invention to'make the receiving apparatus 8 at the subscribers station of any desired type, there being no need to limit it to the simple types of receiving apparatus herein mentions It is, portant feature of my invention that the results attainable with a simple receiver apparatus connected according to my invention, are on a par with those usually attainable on] with a high powered long range receiver suc as the superheterodyne' i e service rendered by the central stato its subscribers includes a certain range in point of distance, and also a certain range. in point of wave lengths through which select-ions can' be made under, the supervision of the operators. For example, from 200 130600 meters is the usual range of short wave lengths used in ordinar telephone broadcasting. The wave lengt s an plied by the oscillators O, O, 0 should e Such. that they will form a heterodyning scalewith the broadcasting wave lengths of the stations. listed and intended to be received bythe subscriber. Each subscriber will have to do his own tuning aszat present,

so hr'ashisantenna circuit'and local receiv'i'ng circu t is concerned, but this is when the instrument is calibrated simple and standardized, involving merely the setting of'the variable condensers or equivalent papparatus to readings taken from a table. eydnd; thislthe subscriber has nothing to do except to ask central for the station wanted. He is thereupon supplied with unmodulated oscillator current of such a frequency that the difference between it and the frequency .of the waves used by the station wanted, will be theuniform beat frequency to which all thed subscribers instruments 7 are standardihe' a I 'The 0 erator is provided in each cord circuit with a key K by means of which she can include her headset Hfin the plate circuit and therefore in series with the line and the subscribers instrument. It is possible for Iproviding a separate'detector at the subwired line however, an imfrequency to make this a bridging arrangement by,

using a bridging battery in the plate circuit, with radio and audio choke coils in the battery bridge. The, plate-filament branch of the tube, the subscribers circuit, and any temporary connection of the operators set would then all be in parallel with the battery, and the subscriber and the operator can talk back and forth over the circuit of the high frequency high potential pulsatingplate current. The same is true of the series arrangement.

I claim: p

1. In a system of radio broadcast distribution, a central station and subscribers stations and wired linecircuits interconnecting them, means at a subscribers station for receiving modulated radio frequency carrier waves, means at the central station for supplying the subscribers station over said with unmodulated periodic current atsuch' a frequency as will heterodyne with the modulated waves received at the subscribers station, to produce a standard modulated beat wave in the subscribers receiver.'

2. In a system of radio broadcast distri-' bution, a central station and subscribers? stations and wired line circuits interconnecting them, means at the subscribers station for receiving ether'waves, means at the central station for generating unmodulated periodic current, switching means for connecting said central office generators interchangeably with said subscribers wired line circuits, and audio receivers at the subscribers station responsive to modulations carried on thestandard beat waves due to the composition of the modulated and the unmodulated waves received through the ether and through the line circuits respecstations and wired line circuits interconnecting them, an oscillator circuit at the central office,

switching terminals therefor, switching terminals for the line circuits, and intermediate connecting circuits with term nals adapted to operate interchangeably with each connecting said switching terminals, 1 circuit including a detector whereby the oscillator current is rectified and transmitted' over the subscribers line as" a high unmodulated high potential pulsating current, adapted to combine with received radio carrier waves to produce an asymmetric modulated beat wave.

4. In asystem of broadcast distribution, a central station, a subscribers station, and a line circuit interconnecting them, a broad east waveabsorbing device at the subscribers station, a receiving and demodulating apparatus for broadcast waves comprising a vacuum tube detector located'at the central station with'its plate circuit extended: over munication betweenv thefcentral station and the subscribers' station by the utilization of,

. the energy of. said plate. circuit.

station, a plurahtyof subscribers stations and them,

switchingmeans for coupling said-oscillator line circuit throughssaid interers stations,and wired line circuits interconmeeting them, tion for receiving broadcast waves and for i the subscribers line, as a high frequenc 'modulated'; high potential pulsating current for use in .demodulating received. ra- 1 "die broadcast :waves, andemeans transmitting them to the line cillator circuit at'the central.

to supply waves for combination withftherev ceived radio broadcast waves,

intermediate connecting so .tral station each 5. phone system comprising a telephone central wired line circuits"interconnecting-them, a

b1 11 frequency Wave receiving device at each cribers station,

station, means toof said tube over central station to. the connected subscriber-3s station over the plate circuit of said vacuum I 'tube. i Q v 6. In a system of radio broadcast distribu-.

tion, a central station,

and asubscribers station and a w red line c rcu t interconnecting anoscillator circuit. at the central station,;in intermediate connecting circuit and circuit to the circuit including a lator current is rectified and transmitted over irect lishing telephonic communication between tion over the high potential direct current circuit circuits, an osa plurality of circuits cally conducting vacuum tube, and. switching means for connecting the oscillatorin common' to a plurality of subscribers flines;

A combined radio broadcast and tele vacuum tube detector responsive a demodulating circuit having its plate circuit connected to said re for saidhighffrequency waves comprising a,

vacuum tubeat the central. complete the plate circuit any one of said line circuits,

and means for 'es- ,tablishing telephone communicationJfrom-the ing device at said station,

mediate connecting. OlICllit, said connecting. detector wherebythe oscilfor estabthe central station and the subscribers' staiand causing the at the cen-' comprising an asymmetry through' individual connecting circuits, soas 8. Ina system ofbroadca'st distribution, a"

receiving station, a broadcast wave absorbing device at said station, and a receiving and emodulating apparatus for broadcast waves comprising a source of oscillations and a thereto and centrahzed distribution system is-maintained.

*9. In a system of broadcast distribution, a receiving station, a broadcast wave absorband a receiving and demodulating apparatus forbroadcast waves comprising means for supplying said station with unmodulated high potential pulsating.

direct current at a'frequency of the same order as that of the; broadcast waves and means at said station for combining said currents broadcast waves to; produce audible eflects in e0v j v ca I produce audible waves in a su1t-' i with the. absorbed energy of said modulated a telephone receiver, sald receiving anddemodulating apparatus being separated, whereby a centralized distribution systemis' maintained. I

10. In a system of broadcast distribution the method of receiving signals modulated I i I a on carrier waves of superaudio frequency 7. In a system of'radio broadcast distribus tion,'a central station, a pluralityofsubscribwhich consistsfin absorbing the energy ofsa'id; waves, producingata distant pointother en-" ulsating-current at afrequency of the same waves, transmitenergy,

orgy in the form of unmodulated asymmetric means at each'subscribers sta- I Iorder as that of the absorbed ting said produced station adapted combining said produced energy, with said absorbed waves:

nalsignal modulations.

signature.

resultant current waveto prod duce sound waves correspondingto the origia r a In testimony whereof' I hereuntolaflixmy 1 Y

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