Патент USA US2114332код для вставки
April 19, 1938. R. BRUCKNER ET AL 2,114,332 KEYING Original Filed Jan. 8, 1934 171:9" i 4139’ 5 By VTORS 3/04/71?” BBUC/f/VEH I900 VLF 60572. EH’ ' ATTORNEY , Patented Apr. 19, 1938 2,114,332 UNITED STATES PATENT FFl€E 2,114,332 KEYING Richard Bruckner and Rudolf Giirtler, Berlin, Germany, assigncrs to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H., Berlin, Germany, a corporation of Germany Application January 8, 1934, Serial No. 705,681. Renewed October 21, 1936. In Germany Jan uary 9, 1933 8 Claims. (Cl. 250-17) This invention relates to a method of and a circuit arrangement for the simultaneous keying of a self-excited and a separately-excited stage of a valve transmitter. Telegraphic transmitters which by keying shocks‘resulting from hard thumping of the key may cause serious disturbances especially in re ceivers located at close distances, should be keyed gently and smoothly. Now, if such a transmitter 10 including one or more stages is keyed gently in a separately-excited stage, but not in the oscilla tion generator of the transmitter it is found that the continuously oscillating generator produces waves which become troublesome. Upon the key ing signals is superposed a permanent tone when heterodyne reception is used which tends to blur the difference between dash and space or inter vals. Inasmuch as in most instances, the fre quency of the oscillation generator of the trans mitter differs during spaces from that during a dash, it may happen that the receiving station is adjusted to space signals with the result that negative signals are received. In order to prevent this from happening the The grid blocking voltages of the keyed sep~ arately-excited ampli?er or repeater stages and the generator stage are derived from a joint volt-‘ age source by way of retarding means, the ratio between the used and the least necessary block ing voltage being chosen lower for the exciting (A stage than for the separately excited stage. The novel features of our invention have been pointed out with particularity in the claims at the end of the speci?cation. Our method of key ing will be better understood from the following 10 description thereof and therefrom when read in connection with the drawing in which Figures 1 to 5 inclusive show circuit diagrams which in clude the essential elements for keying the gen erator and. a stage of the transmitter ampli?er. The idea upon which this invention is predi cated shall be explained in more detail by refer ence to the exempli?ed embodiment thereof shown in Figure l of the drawing. i denotes the tube of the exciting stage or initial generator, and 20 ampli?er or repeater or multiplier stages. How ever, because of the “break” regions it is not pos 2 that of a separately excited stage which may be an ampli?er; 3 and 4 denote grid coupling coils, 5 and 6 grid blocking condensers, l and 8 grid direct current resistances; H3 is a keying re lay which short-circuits potentiometer 9 at the 25 rythin of the Morse-code. With the relay being sible to key it conjointly and simultaneously with closed, the grid biasing voltage generator I 2 is the main transmitter inasmuch as upon breaking 30 oil’ or resuming it would also cause shocks and undesired signals in the excited transmitter am pli?er stages or repeaters. For this reason re course has been had to circuit arrangements com prising a plurality of relays in which the genera 35 tor of the transmitter is disconnected only when short-circuited upon the resistance H. The grid direct current of the exciting or generator stage ?ows by way of parts BA and CA of the poten tiometer 9 and the resistance 1 (which optionally may be dispensed with) and results in the biasing voltage for “upper” dash. In the separately ex cited stage the grid direct current flows through the key relay Ill and produces across the termi nals of resistance 8 the biasing voltage for the grid of tube 2 to amplify the upper dash. If, then, the keying relay ill be opened, the capacity 6 will be charged by way of resistances 8 and H 7 generator of transmitter is keyed as well as the the fall of signal in the transmitter ampli?er and repeater stages has been completed; moreover, the generator of the transmitter is re-connected before the ampli?er becomes operative. 40 . Now, the present invention dispenses with the use of a plurality of relays and with the corre so that a negative blocking voltage is applied to 40 sponding complicated relay and retarder circuit the grid of 2. These currents in addition apply a suitable biasing voltage to the grid of the pilot tube 1 by way of the potentiometer Q and re sistance ‘l and a charging potential of the con means. In our invention the desired end, namely, gentle keying of a separately excited transmitter stage or stages and keying of the oscillation gen erator is accomplished in such a manner that the generator becomes disconnected or inoperative only after completion of the decay of the wave in the ampli?er and resumes operation prior to the denser 5. By suitably choosing the resistances 8, ‘i, i i, ii, and of the capacities 6 and 5 the rise and fall of the plate alternating current of both the separately excited and the self-excited tubes is building-up in operativeness of said ampli?er. _ in?uenced. By suitable adjustment of the slid In our invention this is accomplished by the aid of suitable circuit arrangements comprising elec ing contact A of the potentiometer 9 conditions 50 can be made so that the tube 5 will be blocked tric retarder means and a single key or a single v only after blocking'has been e?ected in tube 2, standard keying relay. The principle underly 5.5. ing the invention is as follows: and that tube I will be unblocked before tube 2 has been unblocked. In practice, of course, care 55 2 2,114,332 must be taken so as to provide proper choking, especially in so far as the keying relay I0 is con means connecting the control grid of the other of said tubes to a different point on said ?rst cerned, in order that the switching spark may not give rise to audio frequency disturbances. Another exempli?ed embodiment of the inven tion is indicated in Figure 2. The plate voltage and the grid biasing voltage are derived from a joint voltage source It, the voltage being divided by the resistances 9 and I5. In series with the 10 keying relay I0 generally is a resistance l3. Some of the circuit elements l6, ll, l8, l9, under cer tain circumstances, may be dispensed with. If the form of the building up and decay of the signal should not be perfectly satisfactory it is possible by the insertion of choke-coils to insure extensive changes in the shape of the signals. named resistance, a reactance and a resistance in parallel in one of said last named connections and a circuit connecting the cathodes of both of said tubes to a third point on said ?rst named Two embodiments are shown in Figures 3 and 4. In the case of Figure 3 there is disposed in series with resistance 8 a choke-coil 20 with a parallel resistance 2|; in Figure 4, a choke-coil 22 with parallel resistance 23 is connected between ca pacities 6 and 24. In order that the duration of the rise and fall of the signals may be varied independently of one another, a recti?er is connected in parallel relation to some of the elements so that these elements become operative either only during the rise or only during the fall of the signals. One important embodiment is shown in Fig iii) ure 5. In parallel relation to the capacity 6 is a branch with condenser 25 and a resistance 26 in series, 25 being bridged or shunted by a de vice 21, for instance, a dry recti?er. In the exempli?ed embodiment here shown the recti?er is so connected that it will be permeable or con ductive in the direction of the arrow, that is, upon discharge of the condenser. Then, during the rise of the signal, the capacity 6 will be in~ creased by the capacity 25 and thus also the time-constant and the length of the rise is in ' creased, whereas during the fall of the signal, if capacities 8 and 25 and the resistance 26 are suitably dimensioned, it is initially only the ca pacity 6 and a smaller time-constant that become operative. Having thus described our invention and the operation thereof, what we claim is: 1. A transmitter comprising a thermionic gen erator tube, a thermionic ampli?er tube con nected therewith, each of said tubes having a grid and a cathode, means for keying said gen erator and said ampli?er comprising a source of direct current, a resistance in shunt therewith, a connection between a point intermediate the terminals of said resistance and the grid of said generator tube, a connection between the oath odes of said tubes and one terminal of said source, a connection between another point on said resistance and the grid of said ampli?er 60 tube, a resistance and a recti?er in parallel in shunt to said ?rst named resistance, and a key in shunt with said resistance. 2. A transmitter comprising a thermionic oscil lation generator tube, a thermionic ampli?er tube 65 connected therewith to amplify the oscillations generated by said generator tube, each of said tubes having a control grid and a cathode, means resistance. 3. An arrangement as recited in claim 2 in which a condenser is connected between each of the terminals of said parallel reactance and 10 resistance and the cathode of one of said tubes. ll. A transmitter comprising a thermionic oscil lation generator tube, a thermionic ampli?er tube connected therewith to amplify the oscillations generated by said generator tube, each of said tubes having a control grid and a cathode, means for keying said generator tube and said ampli ?er tube comprising a source of direct current potential, a resistance and a condenser connected in parallel with said source of direct current -, potential, a key connected in parallel with said source of direct current potential, resistive means connecting the control grid of one of said tubes to a point on said ?rst named resistance, resistive means connecting the control grid of the other i of said tubes to a different point on said ?rst named resistance, a condenser connected between the control grid and cathode of said ampli?er tube, a recti?er connected in parallel with said last named condenser and a circuit connecting the cathodes of both of said tubes to a third point on said ?rst named resistance. 5. In a telegraph transmitter, a transmitter tube having input electrodes and having output electrodes connected in a transmitter circuit, an ‘ exciting tube having output electrodes coupled to the input electrodes of said transmitter tube, a source of direct current, a direct current im pedance connected with said source of direct current, a key connected with said impedance 40 to control the potential drop produced across said impedance by said source of direct current, and means connecting points on said impedance to said tube electrodes for rendering said excit ing tube operative and then rendering said trans mitter tube operative each time said key is placed in marking position and for rendering said excit ing tube inoperative after rendering said trans mitting tube inoperative each time said key is placed in the spacing position. 6. A telegraph transmitter as recited in claim 5 wherein said means includes additional direct current impedances in series in said network and current storing devices in shunt to said direct current .network. 7. In a telegraph transmitter, a transmitter tube having input electrodes and having output electrodes connected in a transmitting circuit, an exciting tube having output electrodes cou pled to the input electrodes of said transmitter tube, a source of direct current potential, an impedance connected with said direct current source, a key connected with said direct current source and impedance for controlling the poten tial drop produced in the impedance by said 65 direct current source, a direct current network, including said impedance and key, connecting said source of direct current potential to the electrodes of said tubes to control the operative tube comprising a source of direct current poten 70 tial, a resistance and a condenser connected in , ness thereotby controlling the direct current 70 potential supplied by said source to said elec parallel with said source of direct current poten tial, a key connected in parallel with said source trodes of said tubes, and additional impedance means in said connections between said tube of direct current potential, resistive means con necting the control grid of one of said tubes to electrodes and said network cooperating with 75 a point on said ?rst named resistance, resistive said ?rst impedance and key for rendering said 75 for keying said generator tube and said ampli?er 2,114,332 exciting tube operative and then rendering said transmitter tube operative each time said key is in marking position and for rendering said ex citing tube inoperative after rendering said trans mitting tube inoperative each time said key is placed in the spacing position. 8. A telegraph system as recited in claim 7 3 wherein said network includes current storing devices in shunt to said network and additional direct current impedances in series in said net work. RICHARD BRUCKNER. RUDOLF GiiRTLER.