US2412642A - Electronic telegraph transmitter distributor - Google Patents

Description

.. 17, 1946- J. R. WILKERSON 2,412,542 ELECTRONIC TELEGRAPH TRANSMITTER DISTRIUTOR Filed Aug. 25,1943 2 sheets-sheet 1 /NVEA/To@ JJ?. WIL/(EPSON A @Y ATTO/Q 5v Dec. 17, 1946.

.1. R. wlLKr-:RsoN 2,412,642'

ELECTRONIC TELEGRAPH TRANSMITTER DISTRIBUTOR-- 2 Sheets-Sheet 2 Filed Aug. 25, 1945 l /NVENTOR J. R. WIL/(EPSON A 7' TOPNE V Patented Dec. 17, 1946 UNITED STATES PATENT OFFICE ELECTRONIC TELEGRAPH TRANSMITTER DISTRIBUTOR Application August 25, 1943, Serial No. 499,949

24 Claims. l

This invention relates to telegraph transmitters and particuiarly to start-stop permutation code signal generators and transmitters.

An object of the invention is to generate and transmit permutation code signals Without employing an electromechanical distributor.

Another object of the invention is to time the generation of telegraph signal impulses by means of an electronic generator of oscillatory current.

Another object of the invention is to effect the transmission of successive codeimpulses by means of a counting chain oi electron discharge tubes.

Another object of the invention is to provide a counting chain ofl electron discharge devices in which each of said devices is primed by the electron discharge device preceding it and in which each such device upon being rendered conductive quenches any other of said devices that is then conductive. l

The invention features cold cathode electron discharge tubes as the impulse counting elements of the counting chain.

The invention also features half-wave rectifiers ci the electron discharge type controlled in .succession by the counting chain and selectively in accordance with the impulse elements of signaling codes for controlling the generation of tele-- graph code signals.

According to the embodiment of the invention to be described hereinafter in detail, an electron discharge tube oscillator circuit continuously generates oscillatory current, the cycles of which are equal in length to telegraph signaling impulses of the permutation code type. An electron discharge tube arranged in a detector circuit is associated with the oscillator circuit to produce momentary impulses at the rate of one impulse per cycle of oscillatory current generated by the oscillator. The function of these impulses is to time the beginning of each telegraph code impulse to be transmitted.

A counting chain of cold cathode electron discharge tubes is provided comprising one tube to control the generation of a start impulse, one tube,

for each of the significant impulses of the telegraph code signals to be transmitted, which in the ease of the present embodiment of the invention isa five unit code, wherefore. ve such tubes are provided, and one or two tubes for the stop impulse, depending upon Whether that impulse is tohave a duration equal to the duration of the start impulse and the significant code impulses or is to be longer than unit length. Each of the countingy tubes has its cathode connected through a resistor to the control anode of the tube follow- 2 ing it in the chain andthe start tube has its control anode connected through a resistor to the cathode of the last stop tube so that the countingl chain is in reality a. closed ring circuit. The main anodev of each of the tubes in the counting chain is connected to a common source of positive potential and the cathodes of the tubes are connected through individual cathode resistors shunted by condensers to a common negative source of potential. When any one of the tubes is conductive, current ow-s in its cathode resistor so that its cathode is at a more positive potential than the cathodes of all others of the tubes. When the next tube in the chain is rendered conductive, the condenser shunted across its cathode resistor absorbs the initial current in being charged, so that the development of a potential diierence across the cathode resistor is delayed. Itis a characteristic of cold cathode electron discharge tubes that upon the establishment of a discharge between the cathode and main anode of the tube, the potential existing between said cathode and main anode decreases from the firing potential to the discharge sustaining potential, and since in thepresent circuit the main anodes of al1 of the tubes are connected to the same source of positive potential, the potential difference between the main anode and the cathode in each of the tubes undergoes a like decrease. This collapsing of the potential difference between the main anode and cathode occurs before the cathode condenser ha-s become charged and therefore before a normal potential diierence has been developed across the cathode resistor. previously been conductive, the cathode is morev positive than the cathodes of the other tubes including that of the tube just fired, and therefore the potential difference between the main anode and the cathode in the tube previously conductive, upon decreasing becomes les-s than the discharge sustaining potential so that the. tube becomes` extinguished. After the cathode condenser associated with the tube which .has just been fired becomes fully charged, a normal potential difference appears; across the cathode resistor of that tube so thatA the potential differer1-ce between the main anode and cathodeof the tube plus the potential difference across the cathode resistor is equal to the potential of the external power source and the potential of the cathode is more positive than the potential of the cathodes in the other tubes. With this arrangement involving individual cathode resistors and shuntingcondensers for the tubes and common In the case of the tube which hady connection of the main anodes of all of the tubes to the external source of power without individual anode circuit resistors, each tube upon being red quenches any tube which has previously been conductive.

The control anode of each of the tubes is connected through an individual condenser to the secondary winding of a transformer, the primary of which is included in the output circuit of the previously described detector. Thus the potential resulting from an impulse produced by the detector for each cycle of the oscillator is impressed through the individual condensers upon the control anodes of all of the tubes simultaneously. However, only one tube is iired upon the production of any such impulse, such tube being the one that is primed due to the fact that the tube preceding it in the chain Iis then conductive.

The cathode of the counting tube which is identified with the start impulse is connected to the anode of a diode or half-wave rectiiier tube. The cathodes of the ve counting tubes identiiied with the ve significant impulses of a code combination are connected to individual contact arms of a stepping switch which has ve banks of contacts. The contacts of the several banks are connected in Various combinations, according to permutation code combinations representing a ixed or predetermined message to be repetitously transmitted, to the anodes of other diode tubes. For each position of the contact arms of the stepping switch, conductive paths from the cathodes of the five counting tubes pertaining to the signiiicant code impulses to theanodes of the diode tubes are selectively provided or omitted according to the code combination to be transmitted. Thus as each counting tube becomes conductive and the potential of its cathode becomes more positive, the potential of the diode tube anode to which it is connected if the stepping switch provides such connection will be rendered more positive and the diode tube will be rendered conductive. In the case of the counting tube identified with the start impulse, its cathode is permanently connected to the anode of a diode tube and such tube is invariably rendered conductive.

The cathodes of all of the diode tubes are connected to the control grid of an amplifier tube, the output circuit of which includes the operating winding of a transmitting relay which is biased to drive its armature to the marking contact in the absence of current in its operating winding. As any one of the diode tubes becomes conductive, the potential of its cathode becomes more positive by virtue of the potential diierence developing across a cathode resistor common to all of the diode tubes and thus the grid of the amplier tube is made more positive and the tube is rendered conductive. The anode current in the amplifier tube energizes the operating winding of the transmitting relay and drives the armature to spacing. The armature of the transmitting relay is connected to a telegraph line over which the signals are tobe transmitted and the marking and spacing contacts are connected to marking and spacing potentials respectively. From this it will 'be apparent that a spacing condition is represented by conductivity of one of the diode tubes and conductivity of the amplifier tube and that a marking condition is represented by non-conductivity of a diode tube and the amplifier tube, the transmitting relay being operated to marking by its biasing 4 Winding. Since the stop condition is invariably marking, and neither the amplier tube nor a. diode tube is to be operated to produce a marking signal, the counting tubes identified with the stop impulse have no connection to a diode tube.

The anode circuit of the two counting tubes identiiied with the stop impulse includes the operating winding of a relay which controls the stepping magnet of the stepping switch to step the switch contact arms and set up a new code to be transmitted. This function takes place during the transmission of the stop impulses, so that the positions of the contact arms of the stepping switch are not disturbed during the transmission of the significant impulses of a code combination.

For a complete understanding of the invention, reference may be had to the following detailed description to be interpreted in the light of the accompanying drawings wherein:

Fig. 1 is a schematic circuit view showing the impulse timing and generating apparatus according to the present invention; and

Fig. 2 which is complementary to Fig. 1 and is to be positioned above Fig. 1 is a schematic circuit view showing the power supply connections. line connections and code storage mechanisms.

Referring now to the drawings and particularly to Fig. 1, the reference numeral II designates an electron discharge tube of the vacuum type comprising two triode sections in one envelope which serve as oscillator and detector. It will be understood that two single triode tubes could be employed, if desired, instead of one double triode tube. The right-hand triode section of the tube is the oscillator section and the upper portion of a tapped inductance I2 is connected between the control grid and the cathode of the right-hand triode section of the tube. The lower portion of the inductance I2 is connected between the cathode and ground. A condenser I3 is connected in parallel with the inductance I2 and the inductance I2 and condenser I3 have such inductive and capacitative values respectively that the resonance frequency of the network is equal to the impulse frequency of telegraph signals to be transmitted, from which it follows that the duration of one cycle of the frequency to which the network is tuned is equal to the duration of one impulse to be transmitted. A leakage resistor I4 is connected between the control grid and the cathode of the right-hand triode section. The anode is connected to terminal i6 of a terminal block II which in turn is connected to terminal I8 of a terminal block I9 in Fig. 2. Termil nal I8 of the terminal block I9 is connected to the outer lower armature of a relay 2I, the outer lower front contact of which is connected to positive battery 22. Relay 2I is energizable over a circuit including a battery 23 and a manually operable locking key 24, Relay 2| is operable to establish all power connections to the apparatus shown in Figs. 1 and 2 and when relay 2I is energized, the positive terminal of battery 22 is connected to the anode of the right-hand triode section of tube II. Since the lower section of inductance I2 is connected in the cathode return circuit of the right-hand triode section of tube II, it serves to induce energy into the .upper section of the inductance and thus to sustain oscillation so that with relay 2I energized, the

I3 is tuned.

' The grid of4 the left-hand detector section of tube I I is connected to the upper terminal of inductance I2 so that the potential of the grid of the left-hand triode section is Varied yin accordance with the oscillatory operati-on ofr the network comprising inductance I2V and condenser I3. The cathode of the left-hand triode section is connected to ground andthe anode is connected t terminal I5 of terminal block I'I through the primary winding of a transformer 26 in series with a load resistor 2'I. During the portion of each cycle of oscillation in which the upper terminal of inductance I2 is positive with respect to ground, the grid of the left-hand triode section will be positive with respect to thefcathode of the tube and the tube will be conductive. During the rising portion of the positive half cycle, a Voltage at one polarity is induced in the secondary winding of transformer 26 and during the falling portion of the half cycle, a voltage of the opposite polarity is induced in the secondary. During the negative half cycle, no voltage of any significance is induced in the secondary winding of transformer 28 because the grid of the leithand or detector section of tube II is negative with respect to the cathode and little or no anode current flows, depending upon whether anode current is actually cut oir. The secondary of transformer 29 has one terminal connected to ground and the other terminal connected through eight condensers 28 in parallel to the control anodes 3Ic, 32o, 33e, 34o. 36e, 3'Ic, 38e and 39o of eight gas-lled cold cathode discharge tubes designated by the reference numerals 3i, 32, 33, 34, 36, 3'I, 38 and 39.

The cathode Blk of tube 3| is connected through a resistor 4I to the control anode 32C of tube 32. The catho-de 32k of tube 32 is connected through a similar resistance 4I to the control anode 83e of tube 33. In like manner the cathode's 33k, 34k, 38k, 31k and 38k of. the tubes 33 to 38, inclusive, are connected through individual resistors 4I to the control anodes 34C, 38o. 31e, 38e and 39C of the tubes 34, 38, 37, 88 and 39, respectively. Finally, the cathode 397C of tube 39 is connected through a resistor 4I to the control anode 3Ic oi' tube SI. Thus there is a closed ring of interconnections between the cathodes and control anodes of the eight cold cathode tubes. The cathode ofY each of the cold cathode tubes is also connected through an individual resistor 52 shunted .by an individual condenser 43 to a conductor 443 which extends to terminal 4t of terminal block I'I. Terminal 460i terminal block II is connected to terminal 41 of terminal block Id from which a conductor extends. to the inner lower iront contact of relay 2I, the inner lower armature of which is connected to the negative terminal of battery 23. The positive terminal of battery 23 is grounded. The main anodes Sla, 32a, 33a, 34a, 36a.V and 31a of tubes Si, 32, 33, 84, 38 and 3l` are connected to one terminal of la resistor de, the other `terminaloi which is connected to terminal I- of terminal block I'I. nected to terminal 52 of terminal block I9- which in turn is connected to terminal I8 which receives connection from the positive terminal of battery 22 through the outer lower armatureand front contact of relay 2i. The main anodes 33a and 39a of the tubes 38 and 39 are connected throughl the operating winding of a relay 53j tov the same terminal of resistor 49 to which the main anodes of tubes 3! to 31, inclusive, are di-` 'Ih-is terminal is con.-A

rectly connected. .Thus` the resistor: 49 is `com-- mon vtothe anode circuits of al1' of the tubes;

Upon'the closure of manually operable key 24,.

relay 2.I operates and connects the batteries for operating tube Ii and the cold; cathode tubes. The right-hand triode of tube II at once begins to oscillate at the desired frequency and thedetector section oi the tube. I'I generates one positive and one negative impulse in the secondary of transformer 26 during each positive halfcycle of oscillation of the oscillator' section-of tube II. These potentials are. applied through all ofthe condensers 28 simultaneously to the contro-l anodesiofthey eight cold.` cathode' tubes. As; a result of each positive impulse, the control anode of: each of the coldv cathode tubes is made more positive with respect to the cathode than it previously was. However, the potential of such positive impulse isV insui'cientV to ire the'cold cathode tubes.

It is necessary to prime* one of the tubes in order to set the counting chain in operation, and for this purpose the middle lower armature and make-before-break.contact combination of relay 2I is employed. TheY armature is connected through conductor 54, resistor 55, terminals II I and |09 of terminal blocks I9 and Il to ythe lefthand terminal of the resistor 4I connected between cathode 38k of tube 38 and control. anode 39e of tube 39. The make-before-bre'ak iront contact is left unconnected, and the stationaryl contact with which it cooperates is connected to the positive terminal of batteryV 22. When relay 2I` is operated, there is an instant when the middle lower armature of relay 2 IY has engaged the mov- `able front contact and has not disengaged it from the stationary contact. During this instant battery 22.is connected overzthe path extending from the middle lower armature4 and applies ay positive pulse to the control anode of tube: 39 which res the tube. The discharge transfers to the main gap, and as the middle lower armature of relay 2I completes itsoperation the battery 22 isdisconnected from the control anode'39c of tube 39. The Vfiring potential could be. applied to anyone of the cold cathode tubes, but when applied:v as hereinbefore described, it avoids starting the countingV chain in the middle of a cycle. The discharge current in tube 3,9A iiows through; the' cathode resistor 321, associated with .the cathode 39k: of the tube and raises the potential of the cathode with respect to the cathodes of allofl the other cold cathode'tubes, since nofcurrent is owing 'in' their cathoderesistors 42'. Since the con'- trol anode 3Ic of tube 3l is; connected to the cathode 392i:V of tube 39 through resistor 4I, the potential of the control anode 3Ic of tube 3'! is made correspondingly more positive than the cathode 3Ilc of that tube but :this increase in potential is-'a priming potential only and is insufcient to lire ytube 3|. The condition now existing `is that tube 39 is conductive and' tube 3 lV is primed. Upon the production of the next positive impulse inthe .secondary of transformer 26, the positive. voltage is impressedupon ,the control anodes'` of all of the tubes through condensers 28. In' the case: of 4tube 3I this positive potential further raises' the potential of the control anode 3Ic with respect to the cathode 3Ilcy and tube 3! fires, the discharge transferring at once tothe main anode 3Ia. None of the tubes 32 to938i's .the cathode resistor 42. associated with that tube;

as the current iiows to charge condenser 43 which delays the development of full potential diierence across the cathode resistor 42 with which the condenser is associated. Thus even though -tube 3| is conductive between its cathode and main anode, there is a momentary interval during which the cathode 3|7c remains at substantially the same potential as the cathodes of all of the other tubes except tube 39, the cathode 39k of which is more positive than the cathodes of the non-conductive tubes because the condenser associated with its cathode resistor has become charged by this time and there is a potential difference across its cathode resistor. It is a characteristic of cold cathode gas-filled electron discharge tubes that as soon as the tube becomes conductive in its main gap, the potential diiierence between the main anode and the cathode -decreases to the discharge sustaining potential which is considerably less than the potential diierence which must exist between the main anode and the cathode in order to establish a discharge between those electrodes. Since the main anode 3|a of tube 3| is connected directly to the main anodes of tubes 32, 33, 34, 36 and 31, and is connected to the main anodes of tubes 38 and 39 through the winding of relay 53, which is a low resistance winding, the potential difference between the main anode and the cathode of each of these other tubes is correspondingly decreased. The decrease occurs as a lowering of the anode potentials with respect to the cathodes, because all of the cathodes momentarily remain at the same potentials, while the drop across anode resistor 49 increases due to the anode current of tube 3| added to that of tube 39. The potential diiierence between the main anode Y39a and the cathode 39k of tube 39 at this time is less than the potential difference between the main anode and cathode of any other tube due to the potential difference across the cathode resistor 42, associated with tube 39, and the decrease in potential difference as .tube 3| adjusts itself to the steady operating condition reduces the potential difference in tube 39 below the discharge sustaining potential. This causes tube 39 to be quenched. Thereafter the potential difference across the main gap of tube 39 increases as the drop across anode resistor 49 is decreased due to cutting off of the anode current through tube 39, as the condenser 43 associated with its cathode resistor discharges through the cathode resistor andV as the condenser 43 associated with the cathode resistor 42 of tube 3| charges through the main gap of tube 3|. The value of these condensers is so chosen as to allow the extinguished tube time in which to deionize before the voltage across its main gap rises to the full value. denser associated with the cathode resistor 42 of tube 3| becomes charged, Ithe voltage across the cathode resistor rises to a value which is the difference between the discharge sustaining potential across the main gap of the tube and the voltage across resistor 49 and batteries 22 and 23 in series. Had any other tube or tubes than the tube 39 been conducting at the time that tube 3| was red the voltage across the main gap of such other tube or tubes would have decreased below the discharge sustaining potential and such tube or tubes would have been extinguished in the same manner that tube 39 was extinguished. InV this way the circuit is so arranged .that any tube upon being rendered conductive quenches the tube preceding it in the chain or any other tube that may havebeen conducting at that'time.

As the con-V With the development of a voltage across the cathode resistor 42 associated with tube 3|, the tube 32 is primed by having the potential of its control anode 32e raised above the potential of its cathode 32k to the same potential as the cathode 3|lc of tube 3|. The next positive impulse generated in the secondary of transformer 2B and applied through all of the condensers 28 will cause tube 32 only to become conductive and this tube in becoming conductive will quench tube 3| in the same manner that the tube 3| quenched tube 39. As the detector section of tube continues to generate impulses the cold cathode tubes are iired in succession and when tube 39 is fired. it primes tube 3| by virtue of the connection between the cathode 39k of tube 39 and the control anode 3| c of tube 3|. From this it will be apparent that the counting chain of cold cathode gas-filled tubes goes through repeated cycles of counting operations as long as power remains connected to the oscillator and rectifier tube and to the cold cathode tubes. In each cycle of the chain of cold cathode tubes, eight intervals are counted. The interval between the firing of tube 3| and the firing of tube 32 is allotted to the start impulse, the interval between the iiring of tube 32 and the firing of tube 33 is identiiied with the iirst code impulse, the interval between the firing of tube 31 and the firing of tube 38 is identified with the fifth code impulse and the interval between the firing of tube 38 and the retiring of tube 3| is identified with the stop impulse which has a duration twice as great as the start impulse and the code impulses by virtue of the provision of the two tubes 38 and 39.

There is a connection from the cathode 3|7c of tube 3| to terminal 6| of terminal block which is connected to terminal 62 of terminal block |9. Terminal 62 of terminal block |9 is strapped to terminal G3 of the same block which in turn is connected to terminal B4 of terminal block |1. Terminal B4 is connected to the anode of an electron discharge tube 65 which is a diode or halfwave rectifier tube. The cathode of diode tube 66 is connected through resistor 61 and conductors 68 and B9 to conductor 44 to which the cathodes of the cold cathode tubes are connected through their respective cathode resistors, as previously described. When tube 3| is not conductive its cathode 3|7c is at the potential of con..

ductor 44 and the anode of rectifier tube 66 is at this potential. The cathode of tube 66 `is also at the potential of conductor 44 so that no current ows in tube 96. When cold cathode tube 3| becomes conductive and its cathode 3|lc becomes more positive than conductor 44 by the potential difference across its cathode resistor 42, the anode of tube 66 becomes more positive than the cathode of that tube and tube 66 draws current.

The cathode of tube 66 is connected to the grid of electron discharge tube 1|. Due to the ow of current through the cathode resistor 61 of rectiiier tube 66, the cathode becomes more positive when the tube draws current than it previously was, Thus the grid of amplifier tube 1| is rendered more positive with respect to its cathode and the conductivity of amplifier tube 1| is increased. The anode of tube 1| is connected through the operating winding of a transmitting relay T2 t0 terminal 5| of terminal block which as previously described has positive battery connection through the outer lower armature and front contact of relay 2|. Relay 'l2 is a biased polar relay and the current through the biasing,

winding is inthe direction to drive `the armature .into engagement with its -marking contact, The

anode current of tube 1I ilowing through theoperating Winding of-relay I2 drives the armature to the spacing contact. The armature of relay 'l2 is connected to terminal 80 of terminal block l1 which is connected to terminal 18 of terminal blockl9. A `telegraph line 79 extends from terminal 'I3 of terminal block I9 to a remote station Where it is vconnected through the operating winding of biased polar receiving relay 8l to line battery 82 which is connected in seriesaiding re.- `lation to the marking battery 23 connected through the inner lower .armature and front contact of relay 2|, terminal 16 of terminal block I9,

terminal 'I3 of terminal vblock Il to the marking COntact f relay 12, and therefore is in opposition tothe spacing battery S3 connected through the inner upper armature andiront contact of relay 2i, terminal l1 of .terminalblock I9 and terminal 1-4 of Aterminal `block .il to the'spaoing contact of f -f relay 7.2. While tube ,1l is conductive, the armatureof transmitting relay 12 is held on its spacing contact and no current ilows in line i9 because batteries 82 and 83 are in opposition. Current thrOugh thebiasing winding of relay 8| when unopposed by current through the 4opera-ting winding, drives .the .armature awel from the marking contact which is .connected to ground. The

varmature of relay 8l is connected .to battery 8 2 through uthe winding of selector magnet 84 of a receiving printer which may be of any suitable type such as .the printer shown in Patent 1,904,164, granted April V18, :1933, tels. Morton et al. The

disclosure of 'the lVIorton patent is incorporated lherein byreference as part 4of the present specication The spacing condition impressed on line Y'i91whilerectifier tube'f remains conductive represents the start impulse of a telegraph signal.

code

'32,v 3 3, 34, 36 and 31 are connected -to terminals 8 5, 8.7,V 88,. '89and '91, respectively, of terminal 'block El'. These terminals are connected to tervminals92,93,94, 9 5 and 97 of terminal block I9.

Terminal 9 2 .is connected tothe vdouble-ended contactarm associatedwith the bank A of a stepping switch v193having foul other banks of con- .tacts B, C, D and ,En Certain of the contacts of .contacts 'ci stepping switchbank A that are connectedtospring 9 of keyl 99, when lengaged by the contact .arm associated with'bank A complete 'a conductive p athiromthe cathode 32k of tube j.3 2 to the anodeof Atube llH and thus represent a spaci 1g-. eondition for therst signicant impulse of variouscode combinations set up on the contacts ofthe steppingswitch. The contacts of bankA whichhave no connection will provideno conductive .pathirom the cathode 32k of tube 32 totheQanode of diode l L and. thereforerepresent ra. marking condition.

I'erminal93of terminal block i9 isconnected to the; contact arm, ,associated with contact bank B; and also to. contact spring .3. of the -key,..!2 which intheunoperated` condition .engages spring 2,5 which is connected tdspring Il of key. 99.

19 Spring II of key -`99. is not engaged byspring I9. at this time so that this path may bedisrcgarded, the path to the contact armassociated with' stepping switch bank VB b engthe only one that is of interest at this time. Certain ofthe contacts of .stepping switch bank B are connected along with the connectedcontactsof bank A to spring 9 of keyabut it will be noted that thesecon- 'aCtS .Of .Stepping SWilCh .balk CQHGSDODG 150 some but not necessarily all of the unconnected contacts of bank A. From this it will be apparent that a vconductive path is vextended from the cath.- odejc of tube 33 through the contact arm associated withstepping switch bankB and springs i9 and Il ofkcy 99 to the .anode of diode tube itil .only if.. no conductive path has been establi 'sl 1ed froi n the cathode 321c.of tube 3 2 through the contact arm lof stepping switch bank A and springs 9 and I9 of key 99 to the anode of tube IGI. Thus tube IUI may .be activated to effect the .generation of a spacing impulse for. the second signicantimpulseef the telegraph 00de ,only if the jrst s ignicant impulse of the code has beenmarking. It also follows that diode tube |91 is employed alternatively to establish a lspacing condition for either the first or second significant impulse of the code. vOthers of the contacts of stepping Switch bank B are connected to spring 9 of key 99 which engages spring 7 which in Aturn is connected through terminals 133 and lsllyov terminal blocks i9 and Il respectively to the yanode of diode tube. IBS which has cathode connections identical with those of the diode tubes 6 6 and I i. Still others `of the contacts of. stepping switch bank B have no connection to the anode 'of a diode tube and these contacts represent marking conditions. Thusat the several contacts of contact bank B, ac onductive path maybe established for activating diode tube |91 if it hasnot beenactivated from bank A, a conductive path maybe established for activating' tube [d3 if the rst and second significant impulses of the code are both of spacing nature and tube. l 9 l had been activated fromcontact -bank A, or no conductive path to a diode ytube maybe established, this being a marking condition for the second significant impulse of thecode.

Terminal 99 .of terminal block l 9.is connected tothe contact. arm associated with 'contact' bank C of the'stepping switch. This bankhas certain contacts vconnected tospring 6 of key 99 along with certain contacts of bank B as previously mentioned for completing a .conductive path Yto the anodeof diode tube H33, other contacts connected through springs 3 and .5 of key 9 9 which ,are engaged fwhentheA key is unoperated, and through terminals i536 andjll of terminal blocks Ai9,and.l'l respectively to theanode ofdiode tube Hlilll which `has the same cathode-connections as the diodetubes, ILand 193, and thecontact bank' C has still. other' contacts unconnectedfor setting up marking conditions ofthe thirdsig- .nificant pulse. of telegraph signals. Terminal of-teri'ninalblock I9 is connectedr to s pring `of vkey 99 'which is not engaged by spring 'l when the key is in thenormal condition and is also connected A.tothe .contact arm V.associated with the contact bank `D of stepping switch 99. Certain contacts of bank D areconnectedto springof key 99 for establishing a. conductivepathto the anode of diode tube. |04, othercontactsare connected through springs i and 2. of key 99 and throughterminals I'38.and l39fofterminal blocks i9 .andl flrespectivelyto the anode of diode tube i |96 and still other contacts are unconnected'for 11 setting up marking conditions for the fourth significant impulse of code combinations. Terminal 91 of terminal block I9 is connected to the contact arm associated with bank E of the stepping switch 98. Certain contacts of bank E are connected through springs I and 2 of key 99 to the anode of diode tube |06 and other contacts are left unconnected for setting up marking conditions as the fth and nal signicant impulse of code combinations.

It will be noted that the iive banks of contacts in the stepping switch are arranged to establish conductive paths to the anodes of four diode tubes |I, |03, |04 and |06. This arrangement is predicated upon the assumption that there will be no occasion to have set up in the contacts of the stepping switch the blank or all spacing combination. Should it be desired to provide for this combination as one of the codes stored in the stepping switch 98, this may be accomplished by providing two lseparate sets of connections from the connected contacts of contact bank E, the second set, which would be those arranged to set up a spacing condition for the five significant impulses in the all spacing` combination, to establish a conductive path through additional springs of key 99 to the anode of a sixth diode tube |01 which has been provided in Fig. l with its anode connected to terminal |08 of terminal block I1. Since the all spacing code has not been included among the codes set up on the contacts of the stepping switch and since all other code combinations in a permutation code have at least one significant impulse ofmarking nature, in a iive unit code the live stepping switch banks may be connected to establish conductive paths to anodes of a minimum of four diode tubes as previoush7 described.

As each of the cold cathode tubes 32, 33, 34, 36 and 31 is rendered conductive in succession, relay 12 is operated to marking or spacing, according to the code set up at the particular position of the Contact arms of stepping switch 98. Assuming that during the cycle of the chain of cold cathode tubes now under consideration, the contact arms of the stepping switch are in the positions shown, engaging the last contact of each of the Contact banks, a conductive path will be completed through bank A to diode tube I0 I, for a spacing condition as the iirst significant impulse of the code, a marking condition will be established for the second impulse of the code, since the last contact of bank B is unconnected, a conductive path will be established through bank C to tube |03 for a spacing condition as the third signicant impulse of the code, a conductive path will be established through contact bank D to diode tube |04 as a spacing condition for the fourth signiiicant4 impulse of the code and a conductive path will be established through bank E to the tube |06 as a spacing condition for the fifth impulse of the code. Each time that a cold cathode tube from the cathode of which a conductive path had been established to the anode of a diode tube is quenched, the cathode of the cold cathode tube will return to normal potential, reducing the potential of the anode of the diode tube to that of the cathode of the tube so that the tube no longer draws current and the biasing winding of relay 12 may restore the armature to marking if the next impulse is marking. Since the coldv cathode tubes fire in overlap manner, the quenching of any one occurring as a result of the iiring of the one following it, the diode tubes will be oper- Ygization of the stepping magnet.

ated in overlap manner in the case of two or more spacing signals in succession, `such as the impulses 3, 4 and 5 stored in the last contacts of the banks of the stepping switch, so that there Vwill be continuity between successive spacing signalimpulses andthe armature of transmitting relay 12 will not be operated to marking momentarily between successive spacing impulses.

Upon the ring of tube 38, tube 31 will be quenched. It will be noted that there is a connection from the cathode 38K of tube 3B through terminal |09 of terminal block I1, terminal III of terminal Iblock I9, springs 4 and 5 of key |02 to spring 4 of key 99 which is engageable with spring 5 when the key is operated but which is now out of engagement with the spring. Thus no circuit is established from the cathode 38K of tube 33 to a diode tube and the armature of Sending relay 12 will be operated t0 marking for transmission of the stop signal. The main anode circuit of tube 38 includes the operating winding of relay 53, as previously stated, so that this relay will be operated. The armature of relay 53 has a ground connection supplied through termina1 I I2 of terminal block I1, strapped terminals II3 and I|4 of terminal block I9 and terminal IIB of terminal block I'I to which the armature is connected. The front contact of relay 53 is connected through terminal I|1 of termina1 block I1, termina1 II8 of terminal block I9, winding of slow-release relay II9 and outer upper front contact and armature of relay 2| to grounded battery 48. Relay II9 becomes energized over this circuit and attracts its armature out of engagement with its back contact. Prior to the operation of relay II9, the stepping magnet I2I for stepping switch 98 has been energized in a circuit from grounded battery 48 through the outer upper armature and front contact of relay 2|, winding of stepping magnet I2I, back contact and armature of relay II9, terminal I|3 of terminal block'I9 and terminal |I2 of terminal block I1 to ground. Stepping magnet I2I is preferably of the type that advances the contact arms of the stepping switch on the release of the stepping magnet and picks up the next tooth of the stepping ratchet upon ener- Assuming this arrangement, the stepping magnet I2I upon vbeing released due to energization of magnet II9 will advance the contact arms, which are doubleended, one step thus moving the lower arm out of engagement with the last contact of each of the contact banks and moving the upper arm into engagement with the first contact.

When tube 39 is fired one impulse interval after the ring of tube 38 and quenches tube 38, relay 53 will remain operated due to the fact that the main anodes 38a and 39a of tubes 38 and 39 are connected together so that the oper ating winding of relay 53 is in the main anode circuit of tube 39 also, and relay II9 will remain energized, thus holdingV the energizing circuit of stepping magnet I2| open. One impulse interval following the iiring of the tube 39 which primes tube 3|, the latter tube will be red, quenching tube 39 and again rendering diode tube 66 conductive to operate transmitting relay 12 to spacing for the transmission of the start impulse. Upon the cessation of the discharge current through tube 39, relay 53 is released andin turn opens the energizing circuit for slow-release relay II9. After an interval which'is dependent upon the slow-release characteristic' of relay II9, the

fana/p42 larmature of that relay will vvbereleased and will reestablish the energizing circuit for stepping magnet |2|. The only eiect of energization of stepping magnet |2| is to advance its operating pawl into engagement with the next tooth of Ythe operating ratchet in preparation for radvancement of the contact arms to the second contact of each of the contact banks when tube 38 again becomes conductive after the transmission of the last significant impulse of the code. In the meantime, tubes 32, 33, 34, 3S and 31 are rendered conductive in succession to transmit the code combination which is stored on the first contacts of the contact banks of stepping switch 98. It will be noted that banks A and B have connections on the rst Contact and banks C, D and E do not. Accordingly, the rst and second significant impulses of the code will be spacing 4and diodetubes 10| and |83 will be activated in succession and the third, fourth and fifth signicant impulses will be marking and diode tubes Hill and |06 will not be activated.

The transmitter will repeatedly transmit the seriesof codes set up on the contacts of stepping switch 9S until lockingv key v2liA is opened. The series of codes may, for example, represent a test sentence which is to be transmitted repetitiously for the purpose of testingthe operation of a re- -ceiving printer. It may also be a fixed text or message which has va special significance and is to be transmitted at stated intervals or upon yrequest. Under these circumstances, an attendant could close the key 24 when the fixed messageis -to ybe transmitted and could open it when the sending switch 98 had completed one cycle and thus vhad accomplished the transmission of the message.

Key 99 is provided for makingcircuitchanges tor rpermit transmission of uniform `telegraph reversals, by which is meant alternatemarking and spacing impulses of uniform lengtheach'such impulse having a duration yequal to one telegraph codev impulse. Assume now that key `Slisvoperated. The generation of a spacing impulse in the start interval is not altered since the cathode `3|7c of tube 3| is permanently connected to the anode of diode tube 6B. The conductive path from `the contacts offstepping-switch bank A are interrupted at springs S and Hilf of key 99 .so'that tube 32 uponA being red will vnot activate the diode'tube IDI and the impulsecorresponding to the first significant impulse of -a code-combina.- tion will invariably be marking. The path from the cathode 33k of tube 33 isnow traced not to the 'contact arm associated with stepping switch bank B but in the alternate path through springs 3 and -2 of key |02 andsprings' and Ill of key99 to the anode of `diode tube |0| so that the impulse corresponding to the second significant impulse of a telegraph code will invariably be spacing. There is no alternate path branching of-interrnediate the cathode `kof-tube 34 and the contact arm associated with contact bank C, but the path fromthose of thecontacts of bank C lthat are connected to certain contacts of bank B is open Yat the springs 6 and 'l of key S19-and the path from the other connected contacts of bankC is open at'the springs 3 and 5 of keyl 99 so that no conductive path is established from the rcathode 34k of tube 34to an anode of a' diode tube and the impulse corresponding to the third significant impulse of -a telegraph code will invariably-'be marking. 'From the conductive path extending from'fthe cathode '36k ofV tube [35`to the contact arm associated --with stepping switch bank D, la branching path extends through .coni tacts 'Sand 'lof key 99 .to the anode of diode 'tube |03 so that "at contact bank D a-conductive path from the'catho'de 36k of tube 36 :to the anode of diode tube |3 cannot be linterrupted andthe impulse corresponding to the fourth significant impulse of Satelegraph code 4will invariably be spacing. The impulse 'corresponding fto vthe -last signicant Yimpulse of Va code combination, lthe transmission of which is' controlledv by tube 31 willinvariably be marking because the pathfrom the contacts of stepping switch 4bank E;to the Vcontact arm of which the cathode 31k of tube 31 is connected-is open at the springs and 2 of keyV 99.

A previously mentioned connection from Ythe cathode 38k 'of tube Vv33 which is the rststop impulse timing tube is now of Y interest.- This connection extends to spring 4 Aof key |02 from which the path is continued through spring fr5 and springs li and '5v-of key 99 to the anodenof diode'tube |84. Thus the first half of the impulse which is ordinarily the stop impulse of marking nature will vinvariably ice-spacing.I As there is no provision for any connection whatsoever `from the cathode 3% of tube 39 to a diode tube,the second half of the impulse which ordinarily corresponds to the stop impulse will have a normal characteristic, namely, marking. It 'will be apparent from the foregoing that in each 'cycle fof'operation of the counting chain of cold cathode tubes, four spacing and four marking impulses are transmitted, the two typesof impulsesbeing al'- ternated in an unbroken series. Stepping magnet |2| will be released and reenergized onceffor each cycle of the chain but the variouscodes'set up on the contacts of the stepping switch will have'no effect upon transmitting relay l2v while key 99 remains operated, because the key 99'r provides predetermined shunt paths around the contacts and contact arms of stepping switch 98 or interruptions in the conductive paths from the contacts thereof.

Key |2 when. operated along with key l99 .provides circuit connections for `telegraph .reversals at one-half the frequency of the reversals afforded by key 99 alone, each impulse being twice .the length of the impulses aforded by key 99. No change `isfmade bykey H52 lin the conductive Apath from the cathodeSllc of tube 3|k tothe anode of diodetube 6B so that the impulse transmitted dure ing the interval between the activation of tube3| and the activation of tube 32isspacing. From the cathode 32k of tube S2 a path is traced, not through the contact arm and contact of bankA, the circuit of which is opened at the springs S and SB of key S9 but vthrough a branching conductor, springs and 2 of key |62 now closed, springsll and I of key 93, now closed, to the anode of diode tube |0| so that the impulse transmitted during the interval between the activation of tube 32 and the quenching of that tube by activation of tube 33 is of spacing nature, continuing the spacing impulse corresponding to .the start impulse transmitted by the activation of diode tube 66 and providing a spacingimpulse having a length ,equal to two impulse intervals. The branching path extending from the conductor connected between the cathode lccf tube 33 and the contact arm of stepping switch bank B is now open at the springs 2 and 3 of key lllso that the path must betraced through the contact arm associated with the contacts of bank B,some'of l which are connected tothe spring 9 of key 99'now disengaged from spring l0, others `of which `are connected to the spring 6 of key 99 now disengaged from spring 'l and the remainder' of which have no connection. Thus no conductive path is extended to a diode tube in any positionof the contact arm of contact bank B and the impulse corresponding to the second signicant impulse of a code combination, transmitted under the control of the tube 33, is of marking nature. The conductor connected between the cathode 34k of tube 34 and the contact arm of contact bank C has no branching path and certain of the connected contacts of bank C uare connected to spring 6 of kes 99 which is disengaged from the spring 'I while the remainder of the connected contacts are connected to spring 3 of key 99 which is disengaged from rspring 5. Thus the marking impulse initiated under the control of tube 33 will be extended over the interval during which tube 34 is conductive. The conductor which is connected between the cathode 36k of tube 36 and the contact arm of contact bank D has a branching conductor extending to spring 8 of key 99 which is now engaged by spring I from which a conductive path extends to the anode of diode tube ID3. Thus the diode tube |63 will be activated during the interval that tube 36 is conductive and the impulse transmitted will be of spacing nature. The ccnductor connected between the cathode 31k of tube 3l and the contact arm of contact bank E has a branching conductor through which a path is traced through springs 6 and 5 of key H12, now closed, springs 4 and 5 of key 99, also closed, to the anode of diode tube I U4. Tube |04 Will therefore effect the generation of a spacing impulse during the interval that tube 31 is conductive which continues the spacing impulse generated during the interval that tube 36 is conducting. The conductor which extends from the cathode 38k of tube 38 is connected to spring 4 of key H12 which is now disengaged from spring 5 so that no conductive path is established to an anode of a diode tube. The impulse generated during the conductivity of tube 38 will be of marking nature which is the impulse normally transmitted during the conductivity of tube 38 as distinguished from the spacing impulse transmitted during the conductivity of this tube when key S9 alone is operated. As previously stated the cathode 39k of tube 39 has no provision for a connection to the anode of a diode tube so that the impulse generated during the conductivity of tube 39 is invariably of marking nature. This impulse will continue the marking impulse transmitted while tube 38 is conductive. y

From the foregoing it will be apparent that the signals transmitted during Veach cycle of the counting chain of cold cathode tubes with keys 99 and 02 operated are spacing during the conductivity of tubes 3l and 32, marking during the conductivity of tubes 33 and 34, spacing during the conductivity of tubes 36 and 31 and marking during the conductivity of tubes 38 and 39, this sequence being repeated for each cycle of operation of the counting chain. Thus there are two spacing and two marking signals in alternating relation as distinguished from four spacing and four marking signals in alternating relation when key 99 alone is operated, the impulses being twice as long and the impulse frequency being one-half of that aiorded when key 95| alone is operated. These reversals at the two diiierent frequencies may be used for testing purposes.

Although a particular embodiment of the invention has been shown in the drawings and described in the foregoing specification, it will be 16 understood that the invention is not limited to the particular embodiment, but is capable of modification and rearrangement without departing from the spirit of the invention within the scope of the appended claims.

What is claimed is:

1. In a code transmitter, means for generating current oscillations consisting of cycles equal in length to code signaling impulses, individual means for counting a predetermined number of said cycles as a group to identify them as pertaining to start impulses, signaling code impulses and stop impulses of code signals, means for setting up signaling codes, a transmisison line, a line keying device associated with said line, and means controlled jointly by said counting means and said code setting-up means for controlling said keying device.

2. In a telegraph transmitter, means for generating current oscillations consisting of cycles equal in length to telegraph signaling impulses, individual electron discharge means for counting a predetermined number of said cycles as a group to identify them as pertaining to start impulses, signaling code impulses and stop impulses of telegraph signals, means for setting up telegraph signaling codes, a telegraph line, a line keying device associated with said line, and means controlled jointly by said counting means and said code setting-up means for controlling said keying means.

3. In a code transmitter, means for generating current oscillations consisting of cycles equal in length to coded signaling impulses, means controlled by said generating means for producing momentary timing impulses at the rate of one impulse per cycle of current oscillations, individual electron discharge means for counting a predetermined number of said timing impulses as a group to identify them as pertaining to start impulses, signaling code impulses and stop impulses of coded signals, means for setting up signaling codes, a transmission channel, a keying device associated with said channel, and means controlled jointly by said counting means and said code setting-up means for controlling said keying means.

4. In a telegraph transmitter, means for generating current oscillations` consisting of cycles equal in length to telegraph signaling impulses, means controlled by said generating means for producing momentary timing impulses at the rate of one impulse per cycle of current oscillations, means for counting said timing impulses to identify them as pertaining to start impulses,

vsignaling code impulses and stop impulses of telegraph signals, said counting means comprising a plurality of electron discharge devices interconnected in a closed ring circuit so that each is primed by the electron discharge device preceding it in said ring circuit and is fired by said timing impulse producing means, means for setting up telegraph signaling codes, a telegraph line, a line keying-device associated with said line, and means controlled jointly by said code settingup means and said counting electron discharge devices for controlling said keying means.

5. In a telegraph transmitter, means for generating current oscillations consisting of an integral number of cycles per telegraph impulse interval, means controlled by said generating means for producing momentary timing impulses at the rate of one impulse per telegraph impulse interval, means for counting said timing impulses to identify them as pertaining to start impulses,

signaling code impulses and stop impulses of telegraph signals, said counting means comprising a plurality of electron discharge devices interconnected in a closed ring circuit so that each is primed by the electron discharge device preceding it in said ring circuit and is red by said timing impulse producing means, means for setting up telegraph signaling codes, a telegraph line, a line keying device associated with said line, and means controlled jointly by said code setting-up means and said counting electron discharge devices for controlling said keying means.

6. In a telegraph transmitter, means for generating current oscillations consisting of cycles equal in length to telegraph signaling impulses, means controlled by said generating means for producing momentary timing impulses at the rate of one impulse per cycle of current oscillations, means for counting said timing impulses to identify them as pertaining to start impulses, signaling code impulses and stop impulses of telegraph signals, said counting means comprising a plurality of electron discharge devices interconnected in a closed ring circuit so that each is primed by the electron discharge device preceding it in said ring circuit and is fired by said timing impulse producing means, means for setting up telegraph signaling codes, a plurality of normally non-conductive electron discharge devices adapted to be rendered conductive selectively and successively under the joint control of said counting electron discharge devices and said code setting-up means, a telegraph line, a line keying device associated with said line, and means controlled by said last-mentioned plurality of electron discharge devices for controlling said keying means.

7. In a telegraph transmitter, a plurality of electron discharge tubes, means ior activating said tubes in succession at intervals equal in length to telegraph signaling impulses, a cathode resistor associated with each tube, a plurality of other electron discharge tubes, means for selectivelyy connecting the activating electrodes of certain of said other electron discharge tubes to the terminals of certain of said cathode resistors in combinations corresponding to telegraph signals whereby to cause the connected ones oi said other electron discharge tubes to be rendered conductive concomitantly with the rstmentioned electron discharge tubes served by said certain ones of said cathode resistors, and means controllable by said other electron discharge tubes for generating telegraph signal impulses of one characteristic during the conductivity of any one of said other electron discharge tubes and for generating telegraph signal impulses of another characteristic during non-conductivity of all of said other tubes.

8. In a telegraph transmitter, a plurality of gas-iilled electron discharge tubes, means for activating said tubes in succession at intervals equal in length to telegraph signaling impulses, a cathode resistor associated with each tube, a plurality of vacuum electron discharge tubes, means for selectively connecting the activating electrodes of certain of said vacuum electron discharge tubes to the terminals of certain of said cathode resistors in combination according to telegraph signals whereby to cause the connected ones of said vacuum electron discharge tubes to be rendered conductive concomitantly with the gas-lledelectron discharge tubes served by said certain ones of saidl cathode resistors, and means 'controllable by'saidv vacuum electron discharge tubes -for gen- 18 erating telegraph signal impulses ofoi'ie charac# teristic during the conductivity of any one of said gas-filled electron discharge tubes and for generating telegraph signal impulses of another characteristic during non-conductivity of all of said vacuum electron discharge tubes.

941:1 a telegraph transmitter, a plurality of gas-filled cold cathode electron discharge tubes, means for activating said tubes in succession at intervals equal in length to telegraph signaling impulses, a cathode resistor individual to each tube, a plurality of unidirectionally conductive devices, means for selectively connecting certain of said unidirectionally conductive devices across certain oi said resistors in combinations according to telegraph signals wherebyto cause the connected ones of said devices to be rendered conductive concomitantly with the cold cathode tubes served by said certatin ones of said resistors, and means controllable by said devices for generating telegraph signal impulses of one characteristic during the conductivity of any of said devices and for generating telegraph signal impulses of another characteristic during non-conductivity of all of said devices.

10. In a telegraph transmitter, a plurality of gas-filled cold cathode electron discharge tubes, means for activating said tubes in succession at intervals equal in length to telegraph signaling impulses, a cathode resistor individual to each tube, a plurality of unidirectionally conductive devices having one terminal connected together and to the. low potential terminals of said cathode resistors, means for selectively connecting the other terminals of certain 'of -said diode tubes to the high potential ends oi certain of said resistors in combination according to telegraph signals whereby to causev the connected ones of said unidirectionally conductive devices to be rendered conductive concomitantly with the cold cathode tubes served by said certain ones of said resistors, 'and means controllable by said devices for generating telegraph signal impulses of one characteristic during the conductivity of any of said devices and for generating telegraph signal impulses of another characteristic during nonconductivity oi all of said devices. Y

l1'. In a telegraph transmitter, a plurality of gas-filled cold cathode electron discharge tubes, means for activating said tubes in succession at intervals equal in length to telegraph signaling impulses, a cathode resistor individual to each tube, a plurality of hot cathode vacuum diode electrony discharge tubes, having their cathodes connected together and to thelow potential ends of said cathode resistors, a permanent conductive connection between the anode of one of said diodeV tubes. and the highV potential terminal of one of said cathode resistors whereby to cause said diode 'tube to be rendered conductive concomitantly with the cold cathode tube served by said cathode resistor, means for connecting the anodes of others of said diode tubes to the high potential terminals of others of said cathode resistors in combinations according to telegraph signals whereby to cause the connected ones of said diode tubes to. be rendered conductive concomitantly withV the cold cathode tubes served by said resistors, and means controllable by said diode tubes for. generating telegraph impulses of spacingnature during the conductivity of any of said diode tubes and for-generating telegraph im'- pulses of marking nature during non-conductivity.I of all of said diode tubes, the. diode tube having the permanently connected anode controlling the generation of the start impulse of start-stop telegraph signals.

l2. In a telegraph transmitter, a plurality of gas-filled cold cathode electron discharge tubes comprising one pertaining to the start impulse, one pertaining to each of the significant code impulses and at least one pertaining to the stop impulse of start-stop telegraph signals, means for activating said tubes in succession at intervals equal in length to telegraph signaling impulses, a cathode resistor individual to each tube, said resistors having their low potential terminals connected together, a plurality of hot cathode vacuum diode electron discharge tubes having their cathodes connected together and to the low potential terminals of said resistors, a permanent conductive connection between the anode of one of said diode tubes and the cathode of the cold cathode tube pertaining to the start impulse whereby to cause the diode having the permanently connected anode to be rendered conductive concomitantly with the cold cathode tube pertaining to the start impulse, means for selectively connecting the anodes of the others of said diode tubes to the cathodes of the cold cathode tubes pertaining to the signicant code impulses in combination according to telegraph signals whereby to cause the connected ones of said other diode tubes to be rendered conductive concomitantly with the cold cathode tubes to which the anodes have been connected, and means controlled by said diode tubes for generating telegraph signal impulses of spacing nature during the conductivity of any of said diode tubes and for generating telegraph signal impulses of marking nature during non-conductivity of all of said diode tubes.

13. In an impulse counting system, a plurality.

of -cold cathode tubes, a source of operating potential therefor, means for ring said tubes suc-v cessively, a cathode resistor individual to each of said tubes for absorbing a part of the diierence between the potential of said source and the main gap discharge sustaining potential of the tube served by said resistor, an anode resistor common to all of said tubes for absorbing the remainder of said diii'erence between the potential of said source and said discharge sustaining potential, and arshunt circuit for each of said cathode resistors including means for delaying the appearance of a voltage across the cathode resistor when its associated tube becomes conductive to permit the initial discharge current to increase the potential across said anode resistor and thereby reduce the potential of the anodes of said tubes correspondingly without altering the potential of any of the cathodes, said reduction carrying the anode potential relative to the cathode potential of any tube having a steadystate potential across its cathode resistor below the sustaining potential of said tube and quenching it.

14. In an impulse counting system, a plurality of cold cathode tubes, a source of operating potential therefor, means for firing said tubes successively, a cathode resistor individual to each of said tubes for absorbing a part of the difference between the potential of said source and the main gap discharge sustaining potential of the tube served by said resistor, said part of the difference being less than said discharge sustaining potential, an anode resistor common to all of said tubes for absorbing the remainder of said diieren-ce between the potential of said source and said discharge sustaining potential, said remainder being less than the sustaining potential of the tube, and a shunt circuit for each of said cathode resistors including means for delaying the appearance of a voltage across the cathode resistor when its associated tube becomes conductive to permit the initial discharge current to increase the potential across said anode resistor and thereby reduce the potential of the anodes of said tubes by the amount of said increase without altering the potential of any of the cathodes, said reduction carrying the anode potential relative to the `cathode potential of any tube having a steadystate potential across its cathode resistor below the sustaining potential of said tube and quenching it.

15. In an impulse counting system, a plurality ofcold cathode tubes having a common anode resistor and individual cathode resistors, means for ring said` tubes at intervals in succession, and a shunt circuit for each of said cathode resistors including means for delaying the appearance of an ohmic potential diierence across the cathode resistor when its associated tube becomes conductive to permit the characteristic main gap potential difference reduction in a tube as it is fired to be manifest across the main gap of each other tube and to quench any other conductive one of said tubes by redu-ction of its main gap potential diierence below the discharge sustaining potential.

16. In an impulse counting system, a series of cold-cathode tubes having a main anode, a control anode and a cathode forming a main discharge path and a control discharge path, means for interconnecting the cathode of each tube and the control anode of the next tube in the series, a cathode resistor individual to each tube and effective during conductivity of the tube for applying a priming potential across the control discharge path of the next tube in the series, means for producing impulses spaced in time, an impulse conducting connection between said impulse producing means and the control anode of each of said tubes for aiding the priming potential and firing the primed one of said tubes, a common main anode resistor for said tubes, and a shunt circuit for each of said cathode resistors including Vmeans for delaying the appearance of a p0- tential difference across the cathode resistor when its associated tube becomes conductive to permit the characteristic main gap potential difference reduction in a tube as it is fired to be manifest across the main gap of each other tube and to quench any other conductive one of said tubes by reduction of its main gap potential difference below the discharge sustaining'potential.

17. In an impulse counting system, a seriesof cold cathode tubes having a mam anode, 4a control anode, and a cathode forming a main discharge path and a control discharge path, means for interconnecting the cathode of each tube and the control anode of the next tube in theserie's, and for interconnecting the cathode of the last tube in the series and the control anode of the nrst tube in the series whereby to form a closed ring system, a cathode resistor individual to each tube and effective during conductivity of each tube to apply a priming potential across the control discharge path of the next tube in the series,

means for producing impulses spaced intime, an impulse conducting connection between said impulse producing means and the control anode of each of said tubes for aiding the priming potential and rlng the primed one of said tubes, a common main anode resistor for said tubes, and

a shunt circuit for each of said cathode resistors including means for delaying the appearance of a potential difference across the cathode resistor as its a-ssociated tube becomes conductive to per- Init the characteristic main gap potential diierence reduction in a tube as it is red to be manifest across the main gap of each other tube and to quench any other conductive one of said tubes by reduction of its main gap potential difference below the discharge sustaining potential.

18. In an impulse counting system, a source of impulses spaced in time, a plurality of gas-lled electron discharge tubes having a main anode, a control anode and a cathode, a connection between the cathode of each of said tubes and the control anode of the following tube for priming said following tube, a connection between said source of impulses and each of said control anodes for ring only any one of said tubes that is primed, a source of main anode potential, a common anode resistor connected between the main anodes of all of said tubes and one terminal of said source of potential, whereby all of said main anodes assume substantially the same potential, a cathode resistor individual to and connected between each of said cathodes and the other terminal of said source of potential whereby the potential difference of said source of potential is divided between the cathode resistor, the main discharge gap of any of said tubes that is conductive and said common anode resistor whereas said potential difference is divided between said co-mmon anode resistor and the main discharge gap of non-conductive ones of said tubes, and a shunt circuit for each of saidv cathode resistors including means for delaying the appearance of an ohmic potential difference across the cathode resistor when its associated tube becomes conductive to permit the characteristic main gap potential difference reduction in a tube as it is fired to be manifest between the main anode and the cathode of each other tube and to reduce the potential difference between the main anode and the cathode of any tube then having a potential difference across its cathode resistor below the main gap discharge sustaining potential,

19. In a telegraph transmitter, means for producing timing impulses at intervals equal to the duration of telegraph code impulses, a counting chain of electron discharge tubes for identifying said timing impulses as pertaining to start impulses, signiiicant code impulses and stop impulses of telegraph signals, a stepping switch having contact ,banks equal in number to the number of signiiicant code impulses, a telegraph line, means for keying said line, a plurality of electron discharge tubes equal in number to the maximum number of spacing impulses occurring in telegraph codes to be transmitted for controlling said keying means, a contacter for each of said contact banks, a conductive path from the counting tubes identified with the significant code impulses to said contactors for applying potentials to said contactors in accordance with the counting activation and deactivation of said counting tubes, and conductive paths from noncorresponding contacts of pairs of said contact banksl to said keying means controlling tubes for impressing the potentials of said contactors on said tubes whereby each oi said tubes is controllable non-sequentially from a pair of said contact banks, said connected contacts representing spacing impulses.

` In an electron discharge tube system, a

plurality of trigger-type tubes to be 'activated individually, a source of operating potential Vfor said tubes, acathode resistor individual to each ofA said tubes for absorbing a part of the difference between the potential of said source and the discharge potential across the tube served by said resistor, an anode resistor common to all of said tubes for absorbing the remainder of said diierence between the potential of said source and the discharge potential across any conductive one of said tubes, means for activating said tubes individually, and a shunt circuit for each of said cathode resistors including means for delaying the appearance of a potential diierence across the cathode resistor when its associated tube becomes conductive to permit the initial discharge current to increase the potential across said anode resistor and thereby reduce the potential of the anodes of all of said tubes correspondingly with respect to their cathodes, said reduction carrying the anode potential relative to the cathode potential of any tube having a steadystate potential across its cathode resistor below the minimum discharge potential of said tube and quenching it.

21. In an electron discharge tube system, a plurality of trigger-type tubes to be activated individually, a source of operating potential for said tubes, a cathode resistor for each of said tubes connected between the cathode thereof and said source and comprising the sole inter-cathode couplings among said tubes, a common anode resistor connected between the anodes of all of said tubes and said source, means for activating said tubes individually, and a shunt circuit for each of said cathode resistors including means for delaying the appearance of a potential difference across the cathode resistor when its associated tube becomes conductive to permit the initial discharge current to increase the potential across said anode resistor and thereby reduce the potential of the anodes of said tubes correspondingly with reference to their cathodes, said reduction carrying the anode potential relative to the cathode potential of any tube having a steady-state potential across its cathode resistor below the minimum discharge potential of said tube and quenching it.

22. In an impulse counting system, a plurality of cold cathode tubes having a common anode resistor and individual cathode resistors, means for firing said tubes at intervals in succession, and a capacitor connected in parallel with each of said cathode resistors for conducting the initial discharge current of the associated tube as it is fired and thereby delaying the appearance of an ohmic potential difference across the cathode resistor to permit the characteristic main gap potential difference reduction in a tube as it is iired to be manifest across the main gap of each other tube and to quench any other conductive one of said tubes by reduction of its main gap potential diierence below the discharge sustaining potential.

23. In an electron discharge tube system, a plurality of trigger-type tubes to be activated individually, a source of operating potential for said tubes, a cathode resistor for each of said tubes connected between the cathode thereof and said source, a common anode resistor connected between the anodes of all of said tubes and said source, means for activating said tubes individually, and a capacitor connected in parallel With each of said cathode resistors for conductlng the initial discharge current of the assoaaiaelia elated tube as it is red and thereby delaying the appearance of a voltage across the cathode resistor to prevent the initial discharge current to increase the potential across said anode resistor and thereby reduce the potential of the anodes of said tubes correspondingly relative to their cathodes, said reduction carrying the anode potential relative to the cathode potential of any tube having a steady-state potential across its cathode resistor below the minimum discharge potential of said tube and quenching it.

24. In an electron discharge tube system, a plurality of trigger-type tubes to be activated individually, a source of operating potential for said tubes, a cathode resistor individual to each of said tubes for absorbing a part of the diiierence between the potential of said source and the discharge potential across the tube served by said resistor, an anode resistor common to all of said tubes for absorbing the remainder of said difference between the potential of said source and the discharge potential across any conductive one of said tubes, and a capacitor connected in parallel with each of said cathode resistors for conducting the initial discharge current of the associated tube and thereby delaying the appearance of a voltage across the cathode rcsistor to permit the initial discharge current to increase the potential across said anode resistor and thereby reduce the potential of the anodes of said tubes correspondingly relative to their cathodes, said reduction carrying the anode potential relative to the cathode potential of any tube having a steady-state potential across its cathode resistor below the minimum discharge potential of said tube and quenching it.

JEFFERSON R. WILKERSON.

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