US1818669A - Radio frequency telegraphy and telephony system - Google Patents

Description

Aug. 11, 1931. A BECKMANN- 1,313,669 I Mme FREQUENCY TELEGRAPHY AND TELEPHONY SYSTEM Filed Jan. 9, 1925 2 Sheets-Sheet 1 INVENTOR AUGUST aicmmm ORNEY 1931. A. BECKMANN 1,818,669

111mm FREQUENCY TELEGRAPH! AND mmrnouy syswsu Filed Jan. 9; 1925 2 Sheet-Sheet 2 fig. 5

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INVENT'OR AUGUST BECKMANN 'ITORNEY Patented Aug. 11 1931 UNl TED STATES, PATENT OFFICE AUGUST BECKMANN, OF BERLIN, GERMANY, ASSIGNOB To GESELLSCHAFT Ftl'R D'RAHT- LOSE TELEGRAPHIE M. B. H., OF BERLIN, GERMANY, A. CORPORATION OF GERMANY Y RADIO FREQUENCY TELEGBAPI-IY AND TELEPHONY SYSTEM Application filed January 9, 1925., Serial No. 1,338, and in Germany January 11, 1924.

My invention relates to a novel means and method for disseminating news or intelligence from a central station.

One object of the invention is to provide such a meansand method as will give a very large degree of reliability as well as great efficiency from a standpoint of total power consumed.

Another object of the invention is in the novel method and means for receiving and relaying such intelligence.

Other objects will be apparent from the following description and claims when considered with the accompanying drawings, in which Fig; 1 illustrates the invention as applied to sending;

Fig. 2 illustrates the to receiving; 7

Fig. 3 shows another illustration of the 1n-' vention as applied to sending; I I

Fig. 4 shows an illustration of the relaying arrangement;

Figs. 5, 6 and 7 are schematic diagrams showing the different ways in which the intelligence can be disseminated from a central sending station to the ultimate receivers.

Lately the system of transmission of news invention as applied by means of radio frequency over wires has been repeatedly developed besides wireless telegra hy and telephony by using the postal lines w ich work with low frequency telegraphy and telephony for radio frequency multiple'telegraphy and telephony onthe one hand, and on the other by using the hlgh tension transmission lines of the central stations for conveying news. It was also proposed to utilize the lowtension wire systems which supply light and power for the transmission of news by connecting suitably developed radio frequency receivers to the linesinstead of glow lamps or such. v I

The two methods, namely, the wireless transmission of news and that over wires, are completely different and the only relation between themis that both employ the same a paratus of radio frequency engineering.

he invention has the purpose of organically uniting both operating methods and therefore gives new possibilities of utilization for,

radio frequency transmission of news and im proves the technical usefulness of many a known arrangement. I I

The base for uniting both operating methods is to employ radio frequency waves which are transferred, partly by wireless and partly over wires, for telegraphic and telephonic purposes. According to whether the radio frequency waves traverse the two waysat the same time or after one another, difierent em-g bodinients of the invention are required. For

short distances the waves may have equal or different frequencies and may also have equal or different functions for attaining certain effects. As far as the waves are transferred by' wireless, they may be directive or non-directive; in particular the directive wireless transmission combined with the transmission over wires gives results which can not be attained by the directlve wireless transmission alone. p I For one group "of embodiments of the in-. ventlon, the arrangement can be such, that the radio frequencv waves of the transmitting station are radiated by an aerial as well as transferred to a wire. system. For this purpose the transmitting station may employ one or more oscillation generators. If only one generator is used, it can be coupled to the same tlIIlQtO the :2:

effected bya key (not shown) in any known way. or bya microphone (not shown), the

news is transferred by electromagnetic wave radiation as well as by transmissionover the wire system. Instead of the'tube any other generator may be used. 7 I

Usually more energy is used for supplying the aerial than for the wire system. This fact can easily be taken int'o'c'onsideration in case of the separately excited tube transmitter by generator I coupling the: wire system 6 to the tube generator 2 and the aerial only to the chief tube 1.

Another kind of distribution of energy consists in providing two separate generators for the aerial and for the wire system. In this case both transmitters can be affected by a common keying device (Morse-key or microphone).

Such a transmitter transfers the same news on two ways at the same time. The receivers can also be similarly arranged in such a way that they simultaneously receive the incoming waves from a receiving aerial and a Wire system. A phase regulation which may be necessary in some cases can easily be carried out by known means.

This described two-way radio frequency transference has different technical advantages. In the first place it guarantees an increased surety of transmission of news. If the wire connection is for instance interrupted, the news is transferred on the wireless way; on the contrary if at times the wireless transmission is disturbed by strong atmospherics, the reception of the signals is maintained, as the wire communication is not influenced by these disturbances. Therefore, it is advisable to arrange the receiver in such a way that it can be disconnected from the one way or the other.

Freedom from atmospherics can also be attained in such a way that the waves guided by wires are more amplified than the waves transferred without wires before they are led to the indicator of the receiver.

Fig. 2 shows an example of a receiver. The oscillations which are taken up by the receiving aerial 7 are led across a tuned secondary circuit 8, detector 9, audio'frequency amplifier 10 to the indicator circuit 11, including telephone 12; the oscillations which come from the wire system 6 are led across the tuned circuit 13, detector 14, amplifiers l5 and 16, also to circuit 11. A further advantage of this two way radio frequency system is that the loudness of sound is greater than that of a one way system, and furthermore it is possible to employ a smaller total energy than for wireless transmissionalone.

This system can, for instance, be employed when a large number of receivers get the news propagated by one wireless transmitter. If these receivers, as is mostly the case, lie with in the range of a wire system, for instance, of a central station or of a low tension lighting network, or of a telephone wire system, the transmitter can easily be connected by wire to a central point of this wire system. If the separate receivers are then also fitted with small additional apparatus for connecting them to the wire system, the general transmission of news can be carried out in the described manner according to the two way radio frequency method.

. It is not necessary that every receiver be connected to the wire system and also fitted with an aerial. If some receivers get only wireless news and others only news transferred over wires, the number of the subscribers which receive the news from one wireless central station can be greatly increased according to the present invention. If it is necessary to increase the energy of the transmitter for this purpose, this can easily be carried out by an additional apparatus which also may be a separate smaller transmitter for the wire system.

If the news is transferred across the two ways to two different groups of receivers, it is also possible to transfer different news to these two groups. Two signalling apparatus are then necessary and each influences an oscillation generator, if two separate generators are used. If one generator supplies both transmitting ways, these signalling apparatus must be so arranged that the signals are separately led to the two ways. The different news can be simultaneously transmitted with the same radio frequency wave telegraphically as well as telephonically in contrast with straight wireless communication which can employ this method only with different wave lengths.

In the two-way transmission, according to the invention, different wave lengths can of course also be used for the two ways. In many cases it is advisable to supply the wire system with a lower frequency than the aeriall. If a regenerative tube transmitter is used, this transmitter may contain two oscillating circuits, one of which is coupled to the aerial and the other to the wire system. If a transmitter provided with means for increasing the frequency is user, the wire system can be connected to one of the lower in crease stages, while the aerial is supplied by the highest frequency stage.

3 shows an example for this case. The radio frequency generator 17 supplies with energy, on the one hand, aerial 4; across a frequency transformer 18 which is fitted with two secondary windings and also across one or more further frequency transformers l9, and on the other hand, the wire system 6 across an ordinary transformer 20.

A special embodiment of the invention is required in case the two radio frequency waves are traversed by different waves and the same receiver is set up for receiving both waves. A beat or interference reception can be carried out in this case, if the difference of the two wave lengths has a suitable value, without the receiver having a local oscillation generator.

This kind of beat reception also gives the following possibility. Several receivers which are established in the range of a certain wire system and which get telephonic news by means of radio frequency across this central system, are at the same time adapted for receiving telephonic news transmitted by wireless stations which lie far away from is created in this way.

the sphere of the wire system, by using the radio frequency wave of the wire system as a heterodyning wave. A central heterodyne The second wave can also be used for by-purposes of telegraphic communication in general as, for instance, for calling.

In some further embodiments of the invention the radio frequency waves traverse distances by wire system and without wire system alternately. Either the same wave length is used which first traverses a wire system and is then transferred through a range without wire system, or the wave length is altered at the transition spot. Furthermore, the radio frequency can be amplified or another radio frequency generated at the transition spots.

Fig. l shows, for instance, the scheme of an arrangement in which a larger transference distance is bridged over by means of intermediate stations. News is to be transmit ted from a wireless transmitting station A across the two intermediate stations B and G to a receiving station D which is not drawn in the figure. The station A has a transmitting aerial 21 in which oscillations are set up by any transmitter across the coil 22. The radiated waves are taken upby the receiving aerial 23 of the relay station B and directly transferred to a wire system 25 across a suitable multi-stage radio frequency amplifier, one stage only of which being shown at 24. These oscillations which are guided by the wire system are then taken up by the station (land used for exciting a separately controlled tube transmitter 26'. The aerial 27 of this transmitter again radiates these Waves which finally get to the receiver D.

In this way a long distance can be bridged over by means of a much lower total energy than if only Wireless relay stations are used. Long high tension transmission lines and postal telegraph lines which lie in about that direction which is to be covered, can suitably be utilized for this purpose. In many cases the relay stations in which the wireless transference is altered into a transference over wires require no, or only a small source of radio frequency energy.

Every relay station of this arrangement can be utilized not only for the above described purpose, but also for other purposes,

for instance, by transferring news over wire systems which lie within its range or by transferring wireless news in its sphere on other wave lengths than those whch are employed for the relay service.

If lower frequencies are to be employed for those distances which contain wire systems than for the distances without wire lines, the radio frequency can be increased at the tran sition spot at which new radio frequency energy is generated for wireless radiation, and, on the contrary, the frequency can be decreased iatit'he transitionspot from wireless transference :to that over wires.

This embodiment of the invention described I for the .use of a re lay'line gives new possi- I b1l1t1es for a general transmlsslon' of news.

If,'for instance, as shown by Fig. 5, a central -wireless transmitter 28 provides a series of wireless receiving stations 29 with news, these receivers can transfer this news to further receivers30 which lie in their spheres by means of local Wire systems, for instance, low tension lighting networks. For this purpose .it is only necessary to amplify the received radio frequency waves and to transfer them to the I wire system. Of course, the stations 29 can also be fitted :with transmitting aerials in order to be able to transfer the news to those further receivers which have receiving aerials.

Fig. 6:showsthe converse of Fig. 5'. A wire system, for instance, a high tension long distance wire system, is supplied with energy by a centralstation 31. This station has a radio frequency generator which supplies the Wire v system withradio frequency. The radio frequency receiving stations 32, which, for instance, are arrangedin the sub-stations of the wire system, get the news and propagate it in their districts by means of aerials which, for instance, are effected by separately excited tube transmitters, so that the news can be received by the receivers 33. i

'Itis obviousthat in accordance with what hasbeen said hereinbefore, the sub-stations I ios ployed inv those cases in which the radio fre- I quency waves are transferred at the same time on both ways from the transmitter to a receiver, further energy can be saved, still more than before mentioned. If radio frequency waves are used for the transmission of news in a wire system in which lines of a certain direction are missing, it is appropriate to connect the radio frequency generator to an aerial particularly radiating to that'direction in order also to be able to transmit news to that direction.

Another important embodiment of the inventon is schematically drawn in Fig. 7 A

directive wireless transmitter34 has a characteristic curve of the sphere of action similar to the shape of curve 35. All the receiving stations which lie in about the direction of the lines 36 then receive the news of this transmitter, but not the station 37. If this latter, however, lies within the sphere of a wire system'38 which also passes near the trans- .mitting station 34, it can also be supplied with news by this transmitter by suitably coupling transmitter and receiver to the wire system i 38. In this way such receiving stations which lie within the dead angles or dead spaces of directional transmitters can also be connected to these transmitters.

Having described several embodiments of my invention, I am entitled to all modifications thereof as fall fairly within the spirit and scope of the following claims:

1. In a communication system the combination of means for transmitting radio frequency oscillations by wireless in a directional manner to one group of stations and means for simultaneously transmitting at the same radio frequency by wire to another group of stations without the range of said directive transmission 2. In a communication system, means for generating signal modulated electrical energy, means for electro-magnetically radiating a portion of the energy so generated, and means for simultaneously transmitting over wire another portion of the signal modulated energy, the amount of energy radiated electromagnetically being greater than that transmitted over Wire and the energy sent by wire being transmitted to a locality poorly reached by the energy el'ectromagnetically radiated.

3. In a communication system, the com bination of means for generating signal modulated electrical energy, means for electromagnetically radiating a portion of the energy so generated to a plurality of radio receiving stations, and means for transmitting by wire another portion of the energy so generated to another plurality of stations substantially unaffected by the electromag netic propagation, the amount of energy transmitted by wire tothe last mentioned group of stations being considerably less than the amount of energy electromagnetically radiated.

4. In a communication system, means for generating signal modulated undulating electrical energy, means for transmitting by wire the energy so generated to'a lurality of sub-stations and means at each sub-station for simultaneously transmitting by wire and by electromagnetic wave radiation the energy received to a plurality of independent receivers, the amount of energy radiated at each sub-station being greater than the amount of energy transmitted over wire.

AUGUST BEOKMANN.

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