US1781263A - Synchronizing system - Google Patents

Synchronizing system Download PDF

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Publication number
US1781263A
US1781263A US238823A US23882327A US1781263A US 1781263 A US1781263 A US 1781263A US 238823 A US238823 A US 238823A US 23882327 A US23882327 A US 23882327A US 1781263 A US1781263 A US 1781263A
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US
United States
Prior art keywords
frequency
fork
station
tube
amplifier
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US238823A
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English (en)
Inventor
Lester J Wolf
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
CBS Corp
Original Assignee
Westinghouse Electric and Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westinghouse Electric and Manufacturing Co filed Critical Westinghouse Electric and Manufacturing Co
Priority to US238823A priority Critical patent/US1781263A/en
Priority to DEW81162D priority patent/DE500378C/de
Priority to GB36183/28A priority patent/GB301927A/en
Priority to FR665460D priority patent/FR665460A/fr
Application granted granted Critical
Publication of US1781263A publication Critical patent/US1781263A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04H—BROADCAST COMMUNICATION
    • H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
    • H04H20/65—Arrangements characterised by transmission systems for broadcast
    • H04H20/67—Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency

Definitions

  • My invention relates to radio broadcasting and particularly to the problemof maintaining. two separated broadcasting stations at the same wave length.
  • An operator using a receiving set placed at a distance from each of two broadcasting stations sending the 3 same program may choose from which station he will get the program by tuning to the wave length of one or the other station.
  • the effects of fading often interfere more effectually with the reception from one broadcasting station than from another. If the two broadcasting sta-. tions workon the same wave length thesignal will be received fromthat station which is least affected by the fading and the listener will hear it without knowing or caring from which broadcasting station it arrived.
  • Figure 1 is a diagram of the circuits and apparatus involved;
  • I a Fig. 2 is a diagram of the circuits associated with the, mechanically oscillating systern at the controlled station;
  • Fig. '3 is a diagram of the circuits and apparatus employed for multiplying the frequency.
  • a tuning fork 1 qu'ency At the sending station, a tuning fork 1 qu'ency.
  • Piezoelectric crystals also are suitable Ifort'his ur ose.
  • a V Upon one tine of the fork'l, the coil 2 is provided which is connected to theinput of amplifier 3. The output of the amplifier is connected to the winding of a magnet 4: associated with the othertine of the fork.
  • a member 5 of magnetic material is located between the "free ends of the '-;t1nes.
  • T he output 'of the amplifier 3 is also connected to a modulator 6 by means of which the oscillationsdeveloped in -an oscillation generator 7 are modulated in accordance with the movement of the fork.
  • the oscillations are delivered to. an antenna; 8 by a which they are broadcast.
  • the output of the amplifier is' also delivered to a frequency multiplier which is caused to control the frequency ofanoscillator 11.
  • the oscillatorniaybe merely a power amplifier connected with the last tube of the-frequency multiplier.
  • the outputof l theoscillator is delivered to anantenna 12 from which the signalis broadcast.
  • Any suitable receiving set 16 produces from these oscillations a currentcorresponding to the modu- ⁇ lati'on thereof, that is a. currentcorrespond- .ing to the movenien'tof thefork 1f
  • the current is amplified by the amplifier 17 and impressed upon a line 18 by-whichitis-conveyed' over a short distance jtoftheremote broadcasting station. It is then impressed upon a filter 19 through which it isdelivered to. an amplifier 2O and,'after' passing.
  • the fork 23 is as nearly equal in; frequency to the forkl as can be conveniently; provided.
  • the output coil 241s also connected to a frequency multiplier 30 which controls the. oscillator in thesaine ,way that the frequency multiplier 10 controls the oscillator 11, the oscillator 31 delivers energyto the antenna 32 from which the broadcasting action is radiated.
  • V The signal originates at the microphone "35 which is located in astudio or at the scene of'the'program to be broadcast; This may he remote from one or 'both of the broadcastmg stations.
  • the signal is amplified by amplifier S6 and is impressed upon the line 37; A filter 38.
  • this line connects the line to the "modulator 139, by which the outputof the oscillator 11 is modulated.
  • the line 37 is also connectedthrough a filter il to the modulator 42 which modulatesthe output of the 'osci ldator 3l.
  • the signals impressed upon the microphone 35 are thus reproduced as modulationsupon the energy broadcast from the antennae '12 a and 32.
  • the set 16upon which the en ergy radiated from' the antenna 8'is received is of any desired or suitable type.
  • t is convenient to' have in the apparatus'us lG-both a receiver of .the'ne'utroyne type and areceiverof the superhetero V dyn'e type with arrangements for switching from 'oneto the other, whereby that onemay i V be selected which is best adapted to the con Menace ditions prevailing at the time.
  • prac ticalto use the same amplifier 17 for either 'is' thus conveniently correlated with the imtube 51 is connected to the input of the tube pedance of the filter 19 and amplifier 20.
  • a connection 47 ,Fig. 2 to the midpoint of the primary of the transformer 45 iscontrolled by a signal device such as the key 48 by means of which the switching arrangements at" the receiver 16 may be manipulated.
  • the arrangements in the station at antenna may include signalling devices.
  • the key 48 then affords means for communication between the remote broadcasting station at antenna 32 a'ndthe receiving substation at antenna 15.
  • the output of thefilter 19 is connected to the amplifier 20 which, as illustrated in Fig. 2, comprises two portions, one portion being between the filter 19 and the tube 26 and the other portion being between the tube 26 and the driving magnet associated with the fork.
  • the first portion of the amplifier 20 includes two tubes and 51 arranged incascade.
  • the output of the 52 which is the first tube of the second portion of the amplifier.
  • This portion. also comprises a plurality52, 53 of tubes arranged in cascade.
  • the connection between the two portions comprises a link circuit 54.
  • the connection from the output coil 24 5-. ofthe fork 23 to the amplifier is 'made by 1 the wayof this link circuit.
  • the connection includes a potentiometer 57 comprising a resistor connected across the terminals of the'coil 24. Oneterminal ofthe resistor is connected through a grid-biasing device 60 to the commonconductor for the filaments of the tubes.
  • the adjustable contactor of the potentiometer 57 is connected to the grid of the tube 26.
  • the tube 26 is resistancecoupled to the input of the transformer 56, this coupling comprising the resistor 61 and the condenser 62. a The coupling is completed by theconnection 63 between the link circuit and the T common conduct-or for the filaments.
  • the output circuit from the tube 53, at the exit of the amplifier 20, is connected to the magnet'22 through a phase-control device.
  • the phase-control device is a high-pass filter including condensers 65 and 66 in series, with an inductor 67 in shunt.
  • the filter is so designed thatitscut-olf frequency is close to the naturalfrequency of the fork 23, consequently, small changes in the value of the inductance in the filter will cause relatively large changes in the phase of the currentin the magnet 22.
  • the conductivity of this space is controlled b the grid, which is connected through the grid-biasing device 60 to the common con- 67 is shunted by ductor for the filaments.
  • the device 60 affords anadjustable potential and the shunting effect of thetube 68 upon the inductor 67 is controlled by adjustment of said po- .tential. i a
  • the frequency multipliers indicated at 10 i and 30 in Fig. 1 may be of any desired type
  • the conductors 71 extend from the coil 24 in Fig. 2 to the input of the first tube ,7 2 of the frequency multiplier.
  • the tube 72 the drawing byshowing a heavy iron core for the inductor 76.
  • the other paralleltube 73 includes acondenser 77 and an inductor 78, which together form a parallelresonant circuit for the frequency of a harmonic of the inputto the tube 73.
  • the grid of the tube 79 is connected to the point 80 between the two parallel-resonant circuits in the plate circuit of the tube 73.
  • Thecircuit 7 5-7 6 offers a very large impedance to the fundamental frequency, and only a small impedance to the harmonic frequency,while the circuit 77-78 offers a very large impedance to the harmonic frequency andbut little impedance to the fundamental frequency. Consequently, the voltage impressed upon the grid of the tube 79 isalmost entirely of the harmonic frequency.
  • the output circuit of the tube 84 contains two parallel-resonant circuits, one 85 being resonantto the fundamental frequency of the input of the tube 84 and the other 86 being tuned to a harmonic there of.
  • .-the natural period of the circuit 86 is seven times that ofthecircuit 85.
  • tube -89 isrelated-t the tube 8a in a way analogous to. the relation of thetube 79to the-tube' 'l'g'and the tube 8.91s thefirst-o f a pair of. tubes 89 and 90v forming an amplifier which is adapted totransmit the frequency of i the circuit 86. i
  • the transformer in this amplifier is, therefore, designed for even a higher frequency and its core-should have little or no iron.
  • the tube-:95 is related to tube 90 in a manner similar tothat in Which tube 7 9 is related to the tube 73; vThe tube '95 therefore, amplifies. a frequency higher than anyof'the preceding. tubes. It is connected to-the nexttube by a radio-frequency choke coil 96 and a-condenser 97. r
  • nected is the power tube of the oscillator 31
  • Fig, 1. Itmay be a singlepower tube ora battery of power'tubes arranged in parallel .as desired. v V. -i
  • the natural frequency of the. fork 23 is; maintained'asnearly constant as possible. Inorder to accomplish thisthe fork is encased ina housing 100 of heat-insulating material,
  • a Wooden box Within the housmg; a lamp 10l is provided'to,maintainthe boX-ata higher temperature than its. surroundings. v
  • a second lamp 102' preferably smaller than thelainplOl is located outside the casing. at any pointconvenient for observation.
  • thermostatic circuit controller 103 situated Within thebox 100 establishes a shunt about the lamp .102 whenever the-box is cool and opens said shunt upon-sufficient rise of tern-- iperaturewlthin the box. ⁇ Vhenthe shunt .1s estabhsheda larger current flows through visions for maintaining a constant frequency.
  • the outputyof the circuit 90 includes a force delivered by the coil 2 to theamplifier 8.
  • the action .of this amplifierv impresses f upon the magnet lcurrent which is atthe same frequency as the output from the coil 2.
  • the fork is thus maintained inzoscillation.
  • j j i The body 5 of magnetic material-between the tines prevents the fork from vibrating like a pendulum about its-standard, Such movement would-cause" the right handtine to approachthe body'5 while the left handtine recedesfrom it. ,One air gap is, therefore, decreasing at the time, the other air gap is increasing.
  • the oscillation generator 7 may be con:-
  • the frequency chosenin the embodiment mentioned above corresponds-to a wave length of some 65'. meters.
  • This modulated 65-1Il8t61 radiation is re-. ceived upon'the antenna 15'
  • whichin the above mentioned embodiment is somethou- 0 lio' meter rad ation1s-modulatedat'theirequency sand miles from theantenna Sand: aboutone mile from the antenna32.
  • the receiv ngset may beadjustedbyan attendant stationed near the antenna 15, but
  • the receiving 7 set may be controlled from thestat'ion at the antenna. 32 by manipulating'thekey 48-. Any
  • suitable switching orremote-control device may be associated withthe receiving'set 16 to enable the operator at thebroadcasting stament ofthereceiving set 16, at the antenna 15.
  • the adjust- Theamplifier .17 atthe receiving station increases theforlnfrequency current to a value transmitted readily over the lineld which longenough to. permit the antenna to be well separatedfrom the antennac32 but not long enough to cause serious difiiculty in transnrtting current of this frequency.
  • Intheabove embodimenuit is abouta mile long.
  • the filter-191s a lngh-pass-hlter. It
  • the second part of the amplifier20 acts as the regenerating. amplifierfor the fork 23. It is not,
  • the amplifier for regenerating the fork 23 shall beaportion of the amplifier which increases the current deliveredfronix the filter19. Ifthese two amplifiers are separate it is possible to ad just one without disturbing the adjustment circumstances.
  • the fork 26 is impressed through the condenser 62 and the transformer 56 upon the input of the j tube 52. It is then amplified by the righthand "portion of the amplifierQO and so impresses upon the magnet 22 a current which serves to assist in keepingthc fork 23in 0scillation.
  • a i j i The adjustment of the potentiometer 57 and the design of the amplifier are so chosenv ingfork 23, coil 24, amplifying system and magnet 22, is between the degree which wills prevent rapid dampingand thedegree stated hereinafter.
  • the. natural frequency of the fork 23 differs: but slightly from the frequency delivered by the transformer 55 to the system. As explained be. low, the system includes means whereby the and so. made even closer to the period ofthe current from the line18.
  • i i w i The forks 1 and 28. are so constructed as:
  • the adjustment of thephase relation is accomplished by adjusting the biasing potential upon the gridofthetube .68. r This. changes the internal impedance ofthe tube68 and thereby alters the effectiveness with j and thus results in a slight alteration of the;
  • phase-changing device be used 5 instead of thejfilterjustdescribed, although I have found such a filter preferable. .Also
  • phase-changing device may be locatedat anypoint in the regenerative system from the 11o which it shunts a portion of the. 1nduc-tor67;
  • I may bevinserted between the coil '24 and the' atmospheric conditions between the antenna 8 and the antenna 15.” Fading may cause these impulsesto become so small that they canno longer produce perceptible effect. m When this occurs, the .tork 23 will cont1nue to oscill ate because of-the regenerative-icons nectionthrough the tube'26 to' 'the magnetQ-EZL It the degree of regenerationfi-s :onlyyeryi' slightly less than the damping, the "tor-k "will;
  • Tlrisf tendenoy of the :torktopersist iIlfVlbIffltlOIl, :"thus is a means :tori keeping the broadcasting station at the properirequency duringitheitime that;
  • the control can be obtained with any de
  • the Tfilter therefore serves thedouble purpose of correcting the selective attenuation of the line 18 and ⁇ eliminating'to a large eXtentthe-static impulses.
  • the signals from the microphone are transmitted over the line 37 to both broadcasting stations.
  • the filters 41 and 38 are designed to correct the selective attenuating action of the lines. The energy impressed upon the modulators 39 and 42, therefore, is
  • any receiving set located within the reach of both stations will receive the same signalupon the same wave length modulated in the same Way from either station or from both stations simultaneously.
  • a radio system a broadcasting station, a second broadcasting station remote "therefrom, means for maintaining said stations at the samecarrier frequency comprisan osclllating system at one station and a ing regenerative oscillatory system stimulated thereby at the other station.
  • a broadcasting stat tion a second broadcasting station remote therefrom, means for maintaining said stations at the same carrier frequency comprising an oscillating system atone station and a regeneratlve oscillatory system stlmulated 5 thereby at the other station, the degree of regeneration being sufficientto cause the regenerative systemto continue in'oscillation after stimulation thereof has become ineffective for at leastas long a time as fading can ordinarily render said stimulation ineffective.
  • a broadcasting station a second broadcasting station remote therefrom, means for maintaining: said stations at the same carrier frequency comprising an oscillating system at one station and a regenerative oscillatory system stimulated thereby at the other station and high frequency oscillations one at each station each controlled by the said oscillating system at.
  • a broadcasting station a second broadcasting station remote therefrom, means for maintaining said stations at the same carrier frequency compris- 111g an oscillating system at one statlon and a regenerative oscillatory system stimulated thereby at the other station, frequency multipliers of like multiplying power associated respectively with said oscillating systems, and high-frequency oscillators governed by said frequency multipliers, whereby the high frequency at each station is the same multiple of the frequency of the said oscillating system at one station.
  • a broadcasting station a second broadcasting station remote therefrom,1means for maintaining said stations at the same carrier frequency comprising an oscillating system at one station and a regenerative oscillatory system stimulated thereby at the other station, frequency multipliers of like multiplying power associated respectively with said oscillating systems and, highrequency oscillators governed by said frequency multipliers, whereby the high frequency at each station is the same multiple of the frequency of the said oscillating system at one station, a source of signals, modulators, one at each station, for the respective high-frequency oscillators there and I a communication channel connecting said source of signals to each modulator, whereby the broadcasting from each station is on the same carrier Wave length modulated in the same way.
  • a frequency-determining device including a member having a characteristic period of To I mechanical oscillation, a second frequencydetermining device including a member havmg a characteristic period of mechanicaloscillatlon of approximately the same magn1- tude as the first-mentioned member, means including a thermionic tube for adjusting the a frequency determined by the first-mentioned

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Transmitters (AREA)
US238823A 1927-12-09 1927-12-09 Synchronizing system Expired - Lifetime US1781263A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US238823A US1781263A (en) 1927-12-09 1927-12-09 Synchronizing system
DEW81162D DE500378C (de) 1927-12-09 1928-12-07 Gleichwellensenderanlage mit zwei Sendern
GB36183/28A GB301927A (en) 1927-12-09 1928-12-07 Improvements in radio transmitting systems
FR665460D FR665460A (fr) 1927-12-09 1928-12-08 Perfectionnements aux systèmes de transmission par radios

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US238823A US1781263A (en) 1927-12-09 1927-12-09 Synchronizing system

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US1781263A true US1781263A (en) 1930-11-11

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US238823A Expired - Lifetime US1781263A (en) 1927-12-09 1927-12-09 Synchronizing system

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US (1) US1781263A (fr)
DE (1) DE500378C (fr)
FR (1) FR665460A (fr)
GB (1) GB301927A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2853284A (en) * 1954-06-10 1958-09-23 Mitchell Co John E High velocity heater

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2853284A (en) * 1954-06-10 1958-09-23 Mitchell Co John E High velocity heater

Also Published As

Publication number Publication date
DE500378C (de) 1930-06-20
FR665460A (fr) 1929-09-19
GB301927A (en) 1930-03-07

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