Патент USA US2125953код для вставки
‘Aug, *1'1“ 193-. I _ R. PROCHNOW 2,125,953 RECEIVER OF TELEPHONIG OR TELEGRAPHIC SIGNALS Filed May 28, 1957 2 sheets-sheet 2 [004A use/1mm F 4. EAMPLIFIER I 6 INVENTOR f? U 00 L F PROC‘HNOW BY 7%? T TORNEY . _ W Patent-ed Aug. 9, 1938 * UNITED STATES - ; v 21,125,953 PATENT OFF‘IQE * ‘2,125,953 ’ RECEIVER or TELEPHONIG on TELE ‘ > GRAPHIC SIGNALS Rudolf Prochnow, Berlin, ‘Germany, assignor to Telefunken Gesellschaft fur Drahtlose Tele graphic in. b. IL, Berlin, Germany, a ‘corpora/ tion of Germany Application May 28, 1937, Serial No. 145,196 In Germany March 16, 1936 . 4 Claims. (Cl. 250-8) The general aim to simplify the operation of ible only if reception of telegraphic signals is effected by sonic (audio frequency) modulation commercial receiver apparatus involves the prob lem to make the change from reception of tele ' of the ?rst heterodyne of a superheterodyne re graphic signals to telephonic signal reception ceiver apparatus. However, it is possible in this case to ?lter this note so that the change mecha 5 automatic. It has been suggested in the prior nism will not res‘pondto the said modulation fre-y art to utilize for the said change the direct cur rent component resulting‘ from the recti?cation , Now, the invention shall be explained in more of the incoming radio frequency signals by feed ing the direct current voltage produced by the detail by reference to the accompanying draw ings which show the radio frequency ampli?er 10 10 carrier wave to a time~lag relay which responds only to impulses of long duration. Inasmuch as ?rst detector and initial intermediate frequency ampli?ers, of a heterodyne receiver dia‘gram in telegraphic work the direct current component matically, that is, by rectangles and then shows varies at the rhythm and rate of the signals be tween, zero and maximum, whereas it is constant the elements starting from the second interme 15 diate frequency ampli?er tube in detail. 15 in the reception of telephonic signals the relay In the plate circuit of the intermediate fre responds only to telephone signal reception, and quency.v disconnects the heterodyne employed in the re ception of telegraphic signals. However, this method involves a number of 20 troublesome disadvantages. The change, as will be noted, is a function of the telegraphing speed. If the signals are of long duration it may happen that the automatic device disconnects the hetero dyne although no modulated signals (telephony) are present. This is due to the fact that the 25 time-lag of the relay cannot be pushed to any desired limit. ‘Moreover, in. the case of trans mitters comprising means insuring automatic 30 blocking of the carrier between words (quiescent aerial radiation) the time lapses of telephonic signals are liable to have only the length of a somewhat long telegraphic signal. It will be seen therefrom that the change is apt to be attended with inaccuracies and defects in systems of the said sort. _ . quency amplifier tube H] of Fig. 1 is included a circuit I tuned to the intermediate frequency, and furthermore, an audio frequency coupler transformer 2. If the grid biasing voltage for IE! 20’ is properly chosen, this stage acts as a radio fre quency ampli?er and a recti?er. In coupling re lation' with the tuning circuit l is the second heterodyne oscillator tube 20 which is fed with plate potential by way of the resting contact 22 25 of magnet relay 3. Mixing of the incoming wave, 1. e., the intermediate frequency output of III, and the auxiliary wave supplied by 20, is ef fected in the recti?er circuit 4. The heterodyne voltage transformed in. the circuit is so chosen that it will not contribute any appreciable amount to thevolume control potential. The regulation voltage, on the contrary, is a function of the am plitude of the receiver input potential. Such musical telegraphic signals, according to this in vention, is so designed that automatic change in connections is accomplished by the aid of recti ?ed telephony modulation. telegraphic signals as may be received produce, 35 when beat with oscillations from the second heter odyne 2i), beat notes which are fed by way of the audio frequency ampli?er 30 to the headphones. Across the output terminals of the audio fre quency coupler 2, on the other hand, an alter 40 nating voltage will exist only in case of telephonic In describing my invention more in detail refer ence will be made to Figures 1 to 3 of the draw"; ings, each of which show a different embodiment 45 of my receiver with the control means which puts reception. This voltage is then ampli?ed by audio frequency ampli?er i0, is then recti?ed by full-wave recti?er 50 and then fed to the relay 3. It will be clear that the second heterodyne 20 can 45 be disconnected by the relay only in case of te ation, depending on the type of signal received. This scheme insures another advantage in that, lephony signals. The receiver is always ready to receive telegraphic signals, and it is changed over under certain circumstances, a distinct relay may be dispensed with if the heterodyne is caused to in case modulated signals are coming in. 3 In order to obviate the said defects, a receiver for selective reception of telephonic and non the continuous wave oscillator in or out of oper break off directly by the recti?ed audio frequency According to another object of the invention, 50 the relay is to be dispensed with as shown in Fig. voltage, as shall be shown in more detail further below by reference to Fig. 2. There results the 2. In this arrangement the alternating poten tial furnished from the audio frequency ampli further advantage that also musical telegraphy ?er is recti?ed and is used as a counter-voltage 55 signals may be picked up without a heterodyne so that there results a clean note. Modulation must be derived from the receiver, of course, at a point where the heterodyne fre quency required for the reception of telegraphic 60 signa1$ has not yet been added. This will be feas for a glow tube 8. The output of 50 supplies volt 55 age to a resistor 6!] in the direct current circuit of 8. The resistor 60 is poled to oppose the poten tial supplied by the direct current circuit to 8. The glow tube circuit is a voltage divider for the screen grid potential of the second heterodyne 20 60 2 2,125,953 and supplies the plate potential also.‘ When the audio frequency voltage supplied by 2, 40 and 50 frequency energy is derived, a'recti?er having an input coupled to said output, said recti?er having has attained a certain value in the presence of an. output, an ampli?er circuit having input elec small or no telephony modulations on the received" *1 trodes and having output electrodes coupled to a wave, the said glow tube is caused to go out,jand , "utilization circuit, a second recti?er coupling the the second heterodyne 20 has no screen grid‘ori input of said ampli?er to the output of said ?rst plate potential. By this means aclean-cut and "recti?er, a local oscillator coupled to said ?rst smooth instantaneous circuitchange isisecured.v ' recti?er to impress thereon oscillations to be beat It may be mentioned that the audio ,frequency. > with the intermediate frequency wave energy 10 ampli?er stage 40 in a re?ex circuit scheme may ' whenlthe received wave is modulated by non 1O be combined with the preceding stages of the musical telegraphy ‘signals, said oscillator being receiver equipment. All that is'necessary is to, irrnormally operative, and additional rectifying make sure that this tube will not be a?ected by the automatic volume control regulation, otherr wise it will not operate to cause the receiver to respond to telegraphy except in the presence of telephony. ‘7 ' Another circuit organization is shown in Fig. 3. Inthis scheme the voltage arising across the cou 20 pler 2 in the presence of telephonic’ signals is rec ti?ed and is used in the form of a negative grid bias for the power tube 30 of the audio frequency ampli?er; The plate circuit of the said ‘power tube moreover contains, in addition to the out-1 25 put coupler 6, also a relay 3_ which responds to'a change of the plate current of about 2 milliamps. In case of telegraphy signals, the power tube 30 operates only with a very low negative biasing voltage. This is readily possible since distortions are immaterial. In the presence of modulated signals the power’tube will be more strongly biased so that the incidentally caused change in the plate current disconnects the plate circuit of the sec 35 ond heterodyne 20 bythe action of relay 3. In conclusion, certain phenomena shall be dis cussed which are liable to endanger satisfactory operation of the scheme. Roaring noises, which are likely to arise in receivers of high sensitiveness and which, so far as their action is concerned, 40 are similar to the modulation of a signal may cause the automatic mechanism to respond unless precautionary steps are taken. It is suggested to tune the audio frequency coupler 2 to around 1000 cycles with the consequence that the high fre _ quencies are suppressed. The incoming signals, moreover, must have a certain amplitude in order that the automatic de vice may be operated. It will be readily under stood that unduly feeble signals will lead to fail 501 ure of the automatic device so much less fre quently, the steeper the regulation characteristic of the volume control means. I claim: . ' means excited by energy from the output of said ?rst recti?er for rendering said oscillator inopera tive when said received wave energy is modulated 15 by telephony ‘signals. ' r 3. In a system for receiving wave energy modu lated by telephony signals or by non-musical tele graphy signals, a demodulator of the heterodyne type'including a source of' oscillations and- a ?rst 20 detector excited by received wave energy and by oscillations from said source of oscillators, means for deriving from said detector the beat frequency produced by beating said received wave energy with said oscillations, a beat frequency ampli?er 25 tube having input and output electrodes, means for impressing said beat frequency on said input electrodes, means‘ for biasing the electrodes of said tube to produce plate recti?cation in said tube, an output circuit connected with said output elec 30 trodes, a utilization circuit coupled by a recti?er to said output circuit, an additional recti?er of the full wave type having input electrodes cou pled to said output circuit and having output elec trodes connected in a relay circuit, an additional oscillator coupled to said output circuit to supply oscillations thereto, and means connecting said relay with a circuit of said additional oscillator to render'the same inoperative when said received wave energy is modulated by telephony signals. 4. In a system for receiving wave energy modu 40 lated by telephony signals or by non-musical telegraphy signals, a local oscillator, a ?rst de tector, means for impressing oscillations from said oscillator on said ?rst detector and wave energy to be demodulated on said ?rst detector, an out put circuit coupled with said ?rst detector, said output circuit being responsive to the beat fre quency between said wave energy and said oscil lations from said local oscillator, a beat fre quency ampli?er and recti?er of the electron dis chargetube type having a control grid coupled ' ' 1. In a receiving system to be used for the re ception of telegraphy or telephony signals, a wave ampli?er and recti?er, means for impressing said signals on said ampli?er, a utilization circuit re sponsive to wave energy coupled to the output of said recti?er, a local oscillator coupled to said 60 wave ampli?er and recti?er and normally'opera tive to impress beating oscillations thereon when continuous wave energy is impressed on said am pli?er, the resulting beat note being impressed on said utilization circuit, and additional means cou pled'to' said' recti?er and associated with said os cillator for rendering ‘said oscillator inoperative when signal modulated waves are impressed on said'wave amplifying means. > 2. In a system for the reception of Wave energy modulated by ' telephony signals or by non mus'ic'al telegraphy signals, wave receiving ampli fying and demodulating means of the heterodyne type having an'input on which the wave energy is impressedand an output from which intermediate with said output circuit and having an anode connected in an alternating current output cir cuit, means for biasing the electrodes of said dis charge tube to produce plate recti?cation there in, a utilization circuit, an electron discharge tube ampli?er having an anode coupled to said utiliza tion circuit and having a control electrode, a recti?er coupling said controlling electrode to said 60 second named output circuit, means in said sec ond named output circuit responsive only to cur rent components resulting from the recti?cation of wave energy modulated by telephony signals in said ampli?er and recti?er, a third recti?er coupling said last named circuit to the control electrode of said electron discharge tube ampli ?er, a local oscillator coupled to said second named output circuit, and a relay coupling the anode of said electrondischarge tube ampli?er to a circuit of said local oscillator to control the operativeness thereof. RUDOLF PROCHNOW.