Патент USA US2406813код для вставки
‘sepf.3,1946. u ’ - L. A. DÉ ROSA . 2,406,813 INTELLIGENCE TRAÑSMISSION 4SYSTEMFiled June 18, 1943 5I Sheets-Sheet 2 f6 4.47 ` 4.29 202 L58 140 20g f7 INVENTOR. ¿ou/s A. pf?’os/l Sept. 3, 1946. -- ` L. A. DE4 -RosA 2,406,813 INTELLIGENCE TRANSMISSION SYSTEM A_n Il Il - l IN VEN TOR. LOU/6’ _ A. 11e-R054 BY Armin/EY Patented Sept. 3, 1946 2,405,813 ‘UNIT-eo STATES «PATENT lorrlce ’INTELLIGENCE TRANSMISSIÜN SYSTEM Louis de Rosa, West Brighton, >Staten Island, N. Y., assignor to Federal Telephone and Radio Corporation, Newark ,v N. J., a corporation oi' Delaware Application June 18, 1943, `Serial No. 491,287 10 Claims. .l This invention relates to .improvements in in telligence transmission systems, and more par (o1. `rise-3o) ' 2 subjoined detail description of one embodiment and a modiiication thereof, illustrated in the ticularly 4to systems in which intelligence is trans accompanying drawings, in which: mitted in the form Vof pulses, and lreceived and Fig. 1 is a 'block circuit diagram of a preferred converted into visual intelligence, 5 ¿form oi signal-transmitting apparatus according Systems have `been heretofore proposed in to the present invention; y ` which intelligence in the form of pulses or a Fig. 2 is a partial detailed circuit diagram of series of pulses is transmitted »directly or Toy-car some of the control elements shown in ’block form rier Wave tc a receiver where such 4pulses vare in Fie. i; converted into visual intelligenceeither by means 10 Fig. .3 is a .circuit diagram, partially in block of controlling the pattern on the screen of a form, illustrating an intelligence receiving and .cathode ray tube Yor `by »impressions upon a mov converting system adapted to be used with the ing tape. In `som-e systems y»the characterxto be transmitting system illustrated in Figs. 1 and 2; transmitted is Ádivided `-up-` into »several transverse Fig. 4 shows examples of intelligence `in ’the bands _such as ñve for seven, of several >groups 15 form of letters and numerals of the> type which of »pulses each, the-number position oi pulses in each band fdeterm-ininglthe formation of the transmitted character. The 'pulses «may be sent will be reproduced by ythe >syst-_em `illustrated in Figs. 1. 2 andß; and Fig. 5 is a partial detailed circuit diagram of at -a common frequency, or, it iis sometimes y.adaY modified form „of signal-transmitting appa vautageous to transmit each bandl of :pulses at 20 ratus. different frequencies. ` _ The general arrangement of ya preferred form In all such systems the »interval between of .intelligence determining and transmitting pulses or sets of pulses >is -determinative of the system according to the .present invention is i1 character to "be reproduced' at the receiver, and lustrated in _»Fig. V1. Such .a system may include various means have «been _proposed to produce 25 a suitable keyboard :lo which itself may .be made sets of such timed'pulses in .accordance with the of Well-known construction, the ,keys of which characteristics Yof lthe intelligence ‘to be trans will have indicia »marked thereon vcorresponding mitteil, such as ¿a letter or numeral. In prior to the character of signal .to be transmitted. A systems it `been usual to ypra-form mechan sequence of timed ?pulses will be obtained from >ical patterns which, through the 4use of light tbeelectronic counter circuit l2 and, in accord resconsive ~`tubes >or similar 'glneans form series of ance with the particular :key depressedon the pulses `corresponding1to the letter ‘to be transmit ted, the pattern chosen being controlled by a keyboard Lor :similar means. Such systems and such means vare described, .for example, in the copending app-licationsfof 'Edmond M, Deloraine, S. N. 415,554 .filed October 11941'ra-nd Edmond M. Deloraine, `et al., S. N; 469,056 ‘iiled 'December l5, 1942. . It is one of the objects ci ‘the‘ipresent inven tion to eliminate the .use oi mechanical devices `previously necessary in .nroducing the timed pulses used .as a basis lor 'the iormaticnof char acter-identifying signals. ‘ keyboard l0, these pulses -Will be directed to actu ate one rci’ the gate rtubes 22a, 22h, .230, 2211,2.29I 221° and 22g, .there being seven `of these gate tubes if, for example, the system isa seven band »sys tem. -Each of the gate `tubes is respectively en ergized by oscillators 24a, 24e, 24o, 24d,.24e, .24Je and 24g, _operating at diiîerent .frequencies :f1 to f7 respectively. In the preferred `form of system illustrated, the gate .tubes .22a to 22g inclusive ‘ Y are -connected .throughacommon outputlead to control the modulation vof a vtfansmitter 25 sup plied from. 4a `carrier source .28.v In the case `of .a wire transmission system, as contrasted to a >Another object of my ‘invention is directed "to -45 radio transmission system, the outputs of `the ward >the use .of 4an electronic counter circuit :for gate tubes could 1be conducted »through .a trans deriving sequentially timed Àpulses in an intelli mission line 'to> a receiver in -a Jmanner obvious gence transmissionßsystern. A further objectof this invention is to provide an electronic >counter 4circuit for: deriving se o_uentially` timed `pulses 4in an intelligence trans mission system, :together ‘with ¿controllable means to those skilled inthis art. ` In Fig. 2 v1 have illustrated details of 4aupre 50 ferred form v»of electronic counter circuit, `and »the lmanner »in which such counter circuit is in terconnected with the various gatetubes through for startiugzand stopping Said _counter circuit. switches operated by vthe .keys of keyboard Ill. These and other featureacapabilities and ,-ad The electronic counter ycircuit @|22 may, -for eX "vantages ofthe invention Will‘fap‘pear .from the 55 ample, 4comprise seven gaseous Vdischarge tubes 2,406,813 3 4 able isolating resistors or resistors banks 20a to 20g inclusive. Since the gate tube 22h at fre the other, in a manner known to the art that quency f2, should operate only during the first after the first tube |4a is fired it will energize the period, closure of the switch 40h energizes the second tube |41) which, in turn, will extinguish grid of gate tube 22h by completing a circuit be the tube |4a and energize the next tube |4c. A tween conductors 58 and 60, the conductor 58 be counter circuit of this type is disclosed, for ex ing interconnected with an isolating resistor in ample, in the U. S. patent to Shumard 2,146,862, the bank 20a, of tube |4a through conductors issued February 14, 1939. Thus, the tubes be 62 and 64a. Likewise the switch 40e completes a come conductive and non-conductive sequentially circuit between conductors 65 and 68, thereby down the line until the last tube |4g is energized. connecting the energized conductor 62 with the To extinguish the tube 14g, I provide an addi grid of gate tube 22c. Since the gate tube 22d is tional gaseous discharge tube |411l which becomes to operate at frequency f4 for periods 1 to 4 in conductive after the tube |4g and which will clusive, the switch 40d will complete a circuit then extinguish the latter. The tube |471. will between conductors 10 and 12 which intercon become extinguished automatically after a pre nect the grid of the gate tube 22d to the outputs determined period of time through the resist of the ñrst four tubes of the counter circuit. It ance-capacitance network I6, connected between will be noted in this case that the conductor '| the cathode of the tube |411, and ground. Out is connected to the common conductor 14 which, put leads |8a to |8g inclusive, are respectively connected to the cathodes of the tubes |4a to 20 in turn, connects to conductors 16a, 1Gb, '|60 and 16d, attached through isolating resistors to the |4g inclusive, and as the tubes become sequen respective output leads |8a, |817, |8c and |8d. tially conductive, a pulse will appear on each Gate tubes 22a and 22j producing pulsed energy output lead, the pulse on one output lead being at frequencies f5 and f6 are again required to be timed with respect to the pulse appearing on energized only during the period of conduction the output lead of the prior tube. The electronic of the first tube of the counter circuit. Thus, counter circuit may be started by providing a the closure of switch 40e interconnects the com short pulse on a grid of the first tube |4a. For mon conductor 62 of the ñrst gaseous discharge this purpose a switch 30 may be provided on each tube through conductors 18 and 80 to the gate of the keyboard keys 38. When any key is de pressed the switch 30 is momentarily closed and, 30 tubes of 22e while closure of switch 40j completes a circuit from common conductor 62 through con through leads 32 and 34 will momentarily ener ductors 82 and 84 to the grid of tube 221‘. For gize the grid of the tube |4a from a source 0f the letter chosen, the gate tube 22g will operate power 38. Other means for energizing the grid over the entire band at frequency f" as did gate of a gaseous discharge tube and known to the tube 22a at frequency f1. Thus, closure of switch art may, of course be used. 40g completes a circuit from the common con For the purpose of illustrating the formation ductor 56 through conductors 86 and 88 to the of character-identifying signals by means of the grid of gate tube f". present invention, I have shown in Fig. 2 three |4a to |4g inclusive, so interconnected one with keys which, upon being depressed will transmit pulses of such a character as to form upon the >screen of a cathode ray tube the letter “E,” the numeral “2” and the letter "N.” Each key 38 in addition to the electronic counter circuit start ing switch 30, may include a plurality of switch ing means for interconnecting the outputs of the 45 gaseous discharge tubes |4a to |49 inclusive to the control circuits of the gate tubes 22a to 22g inclusive. For example, if the key corresponding to the letter “E” is depressed the counter cir cuit |2 is initiated into action by the momentary 50 closure of the switch 30 and at the same time control circuits are established through switches 48a, 48h, 40o, 48d, 40e, 40j and 48g. An example of Fig. 4 (A) shows that in the formation of the letter “E” a continuous pulse, or continuous series 55 . of pulses over the entire transmitting band is necessary to form the upper portion of the letter at frequency f1; for frequencies f2 and f3 a pulse need be sent only over the first period; for fre quency f4 pulses are sent over the first four 60 periods; at frequencies f5 and f6 pulses are again only sent during the first period, and for fre quency f7 pulses are again transmitted during Similar switching means are used for other characters in a manner similar to that just de scribed, the manner of arrangement of contacts varying of course, upon the type of letter to be transmitted. In connection with the formation of numeral “2” as illustrated in Fig. 4 (B) the control circuits will differ considerably from those used in making the letter ‘EJ’ For example, at frequency f1 the gate tube 22a will be energized for periods 2 to 6 inclusive and the switch 42a will, upon its closure and through conductors 9S and 92 connect the outputs of tubes |8b to |8f in clusive on the grid of this gate tube through con ductors 90, 92, common conductor 94 and in dividual conductors 86h to 96e, these latter con ductors being isolated from other conductors go ing to the same output leads through other re sistors of the resistor banks 2Gb to 20e. In cer tain instances as for example, for frequency f2 for the numeral “2,” the gate tube must be twice energized and de-energized, for example, it must be energized during the first period, and again for the fifth, sixth and seventh periods. To effect such a control of the gate tube 22h, closure of the switch 42h establishes two circuits to the common conductor |00 through the conductors 98 the entire band. Thus, since the gate tube 22a provides a signal at frequency f1 this gate tube 65 and |02. The conductor 98 can be connected to the common lead 62 which will be the same must be energized for the entire band. Accord one as used, for example, for energizing the gate ingly, the switch 48a connects the outputs of every one of the gaseous discharge tubes to the grid of the gate tube 22a by completing a circuit tubes at frequencies f2, f3, f5 and f6 in connection with the formation of the letter “E.” The sec It will be seen 70 ond conductor |02, however, will be attached through common lead |04 to the individual leads that conductor 50 is connected to conductors 54a, between conductors 50 and 52. 54h, 54e, 54d, 54e, 54j and 54g through common conductor 56. The conductors 54a to 54g inclu sive are respectively connected to the gaseous dis charge tube output leads |8a to |89 through suit |088, |06’f, and |069 to the output leads |86, lßf, and |89, respectively, through suitable isolating resistors in resistance banks 20e, 20j, and 20g. Closure of switches 42C, 42d, 42e, 42f, 42g and 42h _ "Will ¿effect îthe c‘losure of :proper «circuits for `the igat'e tubíesìtzc to§2-2gîinclusive Áto form the desired pulses for ‘the .remaining ¿frequencies ‘1’3 to f7 J inclusive. The various circuits 'may be traced in .the manner given above. For example, 4closure :of switch 132e establishes .energization ~of Athis tube from gaseous discharge tubes `>Nid and hic through output leads ltd and we, individual con ductors Hdd and `-Hde, common conductor ||2 and conductors ~.|-U8 and |10; closure ’of switch Ilî‘fd establishes energieation'of gate tube 22d -from -gas dischargetubes `Mc and Md throughfoutput leads of, ‘for example, V310,000 cycles applied to the verti lcal vbeam-scann-ing plates. These two `scanning Asources zwill, therefore, fcomb'ine 'to Amove the .beamfof ‘the .cathode ray tube slowly across the fface A-of .the kscreen lbut rapidly ‘up and down. A phaser 29B Fmay 'be yused to control the oscillator 12&6 :so that the _picture .of the 4received character 'may =be properly positioned ion the >screen Vof the lßcand ltd, individual conductors |200 and 1206i, common .conductor .H3 and conductors Ilfi and ,11.8. Gate .tube 22e will zbe energized from _gaseous discharge .tubes llib and idc Vcathode nay‘tube. The high frequency generator through output 'leads l8b and |80, individ ual conductors ‘6 iode .ray beam may :be `controlled `from .an 'oscil lator 12815 ‘which through a 4clipper 288, a diiïer entiator '2&0 .and :generator 292, supplies a saw »t'o‘oth :Wave of, for example, 30 cycles tothe hori 'zontal lplates >o'i‘ the rcathode ray tube. The dif tferentiator‘lâlß `may valso key `a second oscillator .2394 controlling 'assaw-tooth wave Agenerator `296 >2.8.6 »may‘alsobe :used to control a reactance tube .2.12 ‘connected 'across the ‘tuned circuit V21|] for themuiïpose #of :scanning this 'tuned circuit at a |2811` and |.28c, common con ductor |26 and conductors |22 and |24. The energization of gate tube 22f .by the gaseous dis frequency #corresponding Yto the `frequency of‘ the vertical scanning -wave Aof :the cathode ray tube. ïllhus, `wher-1 signals on 'frequency bands fl yto f7 :are simultaneousiy received, the circuit 210 will lbe :seguenti-ahy tuned #over ythis »frequency vband ¿at :an 4«exft-merriely rapid «rate corresponding to the verticalscanning frequency -of the cathode ray tube '2184. .Throughthe control tube 274 and the trigger «cincuit 276, the «control grid »282 will only charge tubes bia and -`| 4b may be Ysimilarlytraced 'from Aoutput -leads |8a and |31), individual con ductors 135e and |3021, common conductor '| 34 and conductors `|3iland |32. Since the gate tube 22g at frequency f7 is energized over the entire band, closure ‘o‘f the switch '42g may, through conductors |38 `and |40 establish a circuit from the common conductor 5.6 for 'all o1" 'the gaseous discharge tubes to the grid‘of this :gate tube. permit a signal on the screen when ra signal at i The restabli‘sl'iin'g vorf `circuits fto 'form the letter 30 Athe frequency which is ybeing instantaneously .‘.‘«N” need not >be examined 'in y.detail but can ‘be `scanned being received. Thus, as the hori traced in the manner set forth above. Upon closure ‘of ith-e various vswitches ¿Hic ‘to 44g in clusi've, taken in »connection ‘with conductors |42, ~zontal scanning >of .the cathode ray tube `moves relativelyrslowly across ~the screen, the .grid 2-82 will yproduce -on the screen -a pattern >built >up .of .a seriesof short partial-pulses Whose horizontal lßöe, |88, |90, |92, lâdysislâ, lrä‘ßf," 198g, `2MB, '262 ~.eratcr .Sil .and lWhose vertical position lis deter .position is .determined by the .low `frequency gen and 204. .Attention isdirected-to ythe fact, how mined by .the high frequency .generator .295 .and ever, .that -in the formation fof ’a ycharacter ‘such which, idue to .rapid scanning .of ithe tuning cir as the letter “N," 'it »may be necessary >vto 'start 40 cuit ‘2F50 will, furthermore, .only appear when .a .and .stop the «gate 'tube «three times as, :for :eX `signal is at .a predetermined .frequency .and vat .a ample, the gate -tube .22o at :frequency ‘,7‘3. This time correlated with the .position of ythe Vertical merely requires `-a still »further «contact ‘on the Y.scanning -Wave. _ switch 44e .as will »be readily :appa-rent iffromethe .In cases where thesignal .is not to be .repro drawings. Similar .switches are fused at 4521 duced .on a .cathode ray tube, it .may be unneces and 44e. ‘ sary .to ,provide means for ~scanning the .tuning Since, in accordance with .the mannerfof trans .even though all of the frequencies are received mitting the pulsed character-determining ifea simultaneously. This will be true, for example, tures by .means .of .the circuits »illustrated in Figs. 1 and.2,.eachfrequency-band maybe fcdepending , upon .the form .of the character) simultaneously energized vand simultaneously transmitted 'if 'the .signalsare to .be converted into `visual intelli if the signals are to be .reproduced upon a Inov 'ing tape. `In such .a case it will be merely neces sary to apply the output trom a broad handre ce'iver 'through corresponding filters, .ampliiiers and recti?iers toindividual relays operating pen gence by .means of Aa 'cathode ray tube, the ~receiver must be .provided .with means :for control ling the scanning <of Vsucha.tubezfor-»the‘purpose A cils or other .marking devices. Such a system >is more :fully .disclosed .and described in the afore V_described “Deloraine and .de Rosa cbpending ap of separating the signals on'zthe diiierent fire quencies. .An .example `of an arrangement for receiving and convertingsuch signals into visual intelligence upon .thescreen ofacathoderay-tube is illustrated in Fis. 3. This .system .forms .no _part of the present invention but isY covered .in `the copending application'of Edmond M. Delo-V raine and Louis A. de Rosa, S. N. 489,760 "filed plication. . In the counter .circuit illustrated in Fig. 2, pro vision was made for .stopping the operation of 60 circuit automatically, after one series opera tion. It is _possible that a mere single transmis sion o‘f the signal would be insuñìcient to produce ‘a ,proper image on .the .screen of a cathode` ray ` tube. and for this reason _it ’may be desirable >to June 5, 1943. >This ‘receiver includes a suitable (D C.~ _providea counter circuit whereby each letter will "broad >band receiving apparatus 268 having a "tuning circuit "Z'I'B‘tunable over the range of fre quency y‘l-j" of the transmitter. The output from this tunable circuit '273 controls `the grid of a gas filled tube 214 from Whose anode _and ‘cathode are derived control potentials ‘for a trig ger circuit ‘216 consisting of a ,pair of _pentodes 278, 28'0._ The `output of. one of the pentodes 2.1.8 -is connected to the control grid 282 of the cath. oderay tube 284. Horizontal .travel of .the cath# be repeated .several times. A modiñcation of the coiniter circuit indicated at |.2’ in Fig, 5 will be satisfactory jfor ‘this purpose. .The .counter cir 'c it itself, in this case, .is substantially identical Withfthat ’illustrated in Fig. 2 except that here the last .tubefl'lih is connected .back .to the first .tube Malin thesarne manner fas .each .tube is con nected to .the nextsucceeding vtube .so that as a nesult, .when @nce-.energized »the circuit Will ncon 75 tinue =t0 .operate unless ,positive .-‘means are _pro 2,406,813 7 8 which are opeated when any one of the charac thereof, it is to be understood that it may be embodied in other forms without departing from the principles thereof. Accordingly, it is to be understood that this description is made only ter-forming keys is depressed. Upon depression by way of example and not as a limitation on the vided for stopping it. In order to control the starting and stopping of the counter circuitI l2', I have also shown in Fig. 5 modified switches 30' scope of my invention as set forth in the objects of any key, the switches 30’ will interconnect the and the accompanying claims. lead 2li] attached to the grid resistor for tube I claim: Ma to ground. This connection is momentary l. In a system for the transmission and recep but is sufñcient to reduce the negative bias on the grid of this first tube to start the same oper 10 tion of intelligence, the combination of an elec tronic counter circuit including a plurality of ating and thus initiate the entire electronic coun sequentially firing gaseous discharge tubes, means ter circuit. In the ñnal position of a key 38, deriving a series of sequentially timed pulses from the switch 3B’ closes a second contact which con said gaseous discharge tubes, a corresponding plu nects the cathode of the last tube lllh and the grid of the first tube MU, to ground through a 15 rality of normally non-conductive gate tubes, an condenser 296, via conductor 208. The effect of actuating circuit for each gate tube, a separate this connection is to permit several rotations of energy source for each gate tube, the frequency the counter circuit, during which time a poten of each source being different, transmitting tial is gradually built up on the condenser 206 means connected to the outputs of said gate which will ñnally be suñlcient to extinguish the 20 tubes, means for starting and stopping said elec last tube Mh and simultaneously prevent the first tronic counter circuit. switching means respec tube Ida from firing. The rate at which this po tively interconnecting the outputs of said gaseous tential builds up can be controlled as desired, discharge tubes to the actuating circuits of said but will preferably be such as to permitl several, gate tubes to apply the sequentially timed pulses (as ten) revolutions of the counter circuit before thereto in accordance with the intelligence-signi the same is stopped. Thus, each letter will be fying signals desired, and a receiver, said re repeated several times and a clear picture of ceiver including means converting the received the same on the screen of a cathode ray tube in pulsed signals into intelligencethe receiver is assured. 2. The combination according to claim 1, in Certain details of construction which will be which said switching means comprises a key obvious to those skilled in this art have not been board lnrovided with a plurality of control keys minutely described since they themselves are not each having indicia thereon corresponding to a considered to form any part of the present inven character to be transmitted, and switches inter tion. For example, the _details of the keyboard mediate the outputs of said gaseous discharge l (l have not been illustrated. This keyboard may embody the features of usual keyboards known to the art in which, for example, the depression of one key automatically releases a key already de pressed so that special releasing means for each tubes and the actuating circuits of said gate tubes operated, by said keys. f 3. The combination according to claim l., in which said switching means comprises a key board provided with a pluralityr of control keys key are not necessary. Of course, additional each having indicia thereon corresponding to a means will be provided for releasing a depressed character to be transmitted, and switches inter key without pressing some other character-form mediate the outputs of said gaseous discharge ing key. While I have illustrated in Figs. 2 and tubes and the actuating circuits of said gate 5, the addition of separate switch means for each key to start or start and stop the respective 45 tubes, operated by said keys, and in which said starting means includes an additional switch electronic counter circuits, it will be understood actuated by each key, connected to the grid cir that such a separate switch may be in the form cuit of the ñrst tube, and means controlled by of a separately actuated key, if desired. Fur said additional switches tor momentarily in thermore, while I have illustrated as an example of lthis invention a keyboard in which the keys 50 creasing the grid potential of said ñrst tube. 4. A system for producing intelligence-signify directly operate switches for interconnecting the ing signals comprising, in combination, an elec output of the electronic counter circuits with the various gate tubes, it will be understood by ~ tronic counter circuit including a plurality of sequentially firing gaseous discharge tubes, those skilled in this art that individual keys may ectuate relays for accomplishing this indirectly 55 means deriving a series of sequentially timed pulses from said gaseous discharge tubes, a cor instead of directly, The form of switch mecha responding plurality oi' normally non-conductive nism illustrated has only been given by way of gate tubes and an actuating circuit for cach gate example and it is not intended thatl this inven tube, a separate energy source for each gate tion be limited to any particular type of key-oper 60 tube, the frequency of each source being differ ated switch mechanism. ent, transmitting means connected to the out No means have been illustrated for definitely puts of said gate tubes, means for starting and synchronizing the receiver with the transmitter stopping said electronic counter circuit, and systems above described. Such synchronization switching means respectively interconnecting the is not necessary in most cases and the mere ad outputs of said gaseous discharge tubes to the justment of the scanning voltage by a phaser as actuating circuits of said gate tubes to apply the described to bring the picture of the character sequentially timed pulses thereto in accordance to the center of the screen is usually suñìcient. However, if positive synchronization is desired, with the intelligence-signifying signals desired. this may be effected by the transmission and re 5. The combination according to claim 4, in ception of an additional synchronizing pulse in 70 which said switching means comprises a key board provided with a plurality of control keys the manner known to the art. Such synchroniz each having indicia thereon corresponding to a ing pulse might, for example, be derived from the additional tube of the trigger circuit. character to be transmitted, and switches inter mediate the outputs of said gaseous discharge While I have shown and described one embodi tubes and said gate tubes operated by said keys. ment of the invention and one modiñcation 2,406,813 6. The combination according to claim 4, in which said switching means comprises a key 10 charge tube interconnecting the last tube of said electronic counter circuit with the ñrst tube board provided with a plurality of control keys thereof, whereby said counter circuit will oper each having indicia thereon corresponding to a character to be transmitted, and switches inter in ate in a continuously rotating fashion, and wherein said starting and stopping means in media-te the outputs of said gaseous discharge tubes and said gate tubes operated by said keys, ` cludes a condenser and a ground, means con necting the grid of the ñrst tube to the ground and in which said starting means includes an for reducing the grid bias thereon and render additional switch actuated by each key, con said ñrst tube conductive, and means for con nected to the grid circuit of the iirst tube, and necting the grid of the lirst tube and cathode means controlled by said additional switches for of said additional tube to ground through said momentarily increasing the grid potential of condenser to build up sufficient potential on said said ñrst tube. condenser after a number of cycles of operation 7. The combination according to claim 4, in which the means for stopping said electronic l. to extinguish said additional tube without re energizing the grid of said first tube, whereby counter circuit comprises an additional gaseous said counter circuit will cease to operate. discharge tube for extinguishing the last tube of said counter circuit, and a condenser-resistor leakage circuit connected to the cathode of said additional tube for extinguishing the same a pre- »z determined time after it has been energized, and in which said starting “circuit includes means for temporarily increasing the grid potential on the ñrst tube of the counter circuit. 8. ’I'he combination according to claim 4, in which said switching means comprises a key board provided with a plurality of control keys each having indicia thereon corresponding to a character to be transmitted, and switches inter mediate the outputs of said gaseous discharge - tubes and said gate tubes, operated by said keys, in which said starting means includes an addi tional switch actuated by each key, connected to the grid circuit of `the ñrst tube and means con trolled by said additional switches for momen tarily increasing the grid potential of said iirst tube, and in which said stopping means com prises an .additional gaseous discharge tube for extinguishing the' last tube of said counter cir cuit and a condenser-resistor leakage circuit connected to the cathode of said additional tube for extinguishing same a predetermined time after it has been energized. . 9. The combination according to claim 4, in combination with an additional gaseous dis 10. The combination according to claim 4, in combination with an additional gaseousr dis charge tube interconnecting the last tube of said electronic counter circuit with the first tube thereof, whereby said counter circuit will oper ate in a continuously rotating fashion, in which said switching means comprises a keyboard pro vided with a plurality of control keys each hav ing indicia thereon corresponding to a character to be transmitted, and switches intermediate the outputs of said gaseous discharge tubes and said gate tubes, and in which said starting and stop ping means includes a condenser, a ground, a negative grid bias on said ñrst tube, an addi tional switch operated by each key, and conduc tors interconnecting each of said additional switches to said ground, said condenser, and the grid of said I-lrst tube and the cathode of said additional tube, so that when a key is depressed each switch first, momentarily connects the grid of said first tube to ground for removing the grid bias therefrom to start the counter circuit op erating, and then in the final depressed position each switch connects the grid of the first tube and the cathode of the" additional tube to ground through said condenser to cut oiT the additional tube without starting the first tube after a num ber of cycles of operation of the counter circuit. LOUIS A. DE ROSA.