US2083653A - Transmission system - Google Patents

Transmission system Download PDF

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Publication number
US2083653A
US2083653A US663574A US66357433A US2083653A US 2083653 A US2083653 A US 2083653A US 663574 A US663574 A US 663574A US 66357433 A US66357433 A US 66357433A US 2083653 A US2083653 A US 2083653A
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Prior art keywords
distorting
current
phonograph
record
compensating
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Expired - Lifetime
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US663574A
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English (en)
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Kasemann Erwin
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Individual
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Individual
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04K—SECRET COMMUNICATION; JAMMING OF COMMUNICATION
    • H04K1/00—Secret communication
    • H04K1/02—Secret communication by adding a second signal to make the desired signal unintelligible

Definitions

  • My invention relates to improvements in transmission systems and more particularly to a method of producing distorting and compensating cur-A ing current opposite in phase Vto the distorting current, and that said distorting and compensating currents are produced by picking up at each of said stations, a single point of a single finite phonograph record.
  • These transmission systems have been found to be vunable to fulnll their purposes of maintaining the desired secrecy, since the individual records of a single phonograph record picked up at only a single point, repeat after a certain time, so that unauthorized persons may easily determine the distorting alternating currents by oscillographing the transmitted messages and then may decipher further messages.
  • Another object of the present invention is' to provide a method of producing distorting and compensating currents, which allows the shape of curve of said currents to vary in any desired manner, although phonograph records with unvariable records are used, so that, even if the phonograph records used would be'known to an unauthorized person, the latter will not be able to decipher the messages.
  • I accomplish the purposes of my invention by a method which consists in producing the distorting andcompensating currents used in the above described method for maintaining secrecy in the transmision of messages by picking up one or .former by the transmission line I0.
  • Another feature of my invention is to -vary the relative effective position of said picking up points to each other' during the picking up operation, so that a deciphering by unauthorized persons is rendered still more diflicult.
  • Fig. 1 is a diagrammatical view of an arrangement of a transmission system embodying the features of my invention, whereby single phonograph records with two picking up points are used at the sending and receiving stations;
  • Fig. 2 is a diagrammatical View of the device producing distorting or compensating currents, showing the use of two phonograph records with one picking up point for each phonograph record;
  • Fig. 3 is a diagrammatical plan View of a plate carrying a record
  • Fig. 4 is a diagrammatical side elevational view, showing the arrangement of the plate carrying the record in combination with photoelectrical means to pick up the record.
  • A designates a sending station, and B, a receiving station connected to the 35
  • the telephone variations produced in the circuit II by the operation of the microphone I2 at the sending station A will be transmitted through the transformer I3 to the line I 0.
  • the message current outgoing from the microphone I2 is undistorted during its flow through the circuit I I.
  • a device I4 is provided, which produces a distorting alternating current to be superimposed on the outgoing message current, so that a distorted and unintelligible currents iiows through the transmission line I0.
  • Said device I4 comprises a motor I5, to the shaft I8 of which a plate I'I carrying 50 arecord is secured.
  • the motor I5 rotates the plate I1, and the phonograph record is contacted at two points I8 and I 9 by suitable means comprising for example a transmitter provided with a needle.
  • the transmitters I8 and I9 are connected to each other and to the circuit 20, which in turn is connected to the winding I3!4 of the ⁇ transformer 'I3 and includes an amplifier 2
  • the transmitters produce a distorting alternating current in the circuit'gZll; and the resultantl curve of which is a function of two points of the phonograph record,v so that this curve is entirely different from the original curve of the phonograph record,
  • the distorting current of the circuit 20 is superimposed on the outgoing message current by the transformer I3, so that a distorted current flows through the line I0.
  • the latter is equipped with a device I 4'.' which produces a compensating alternating current to be superimposed to the distorted current arriving from the line I0.
  • Said device I4' com- ⁇ prises a motor I5', which is connected to the motor I5,of the device I4 through a circuit 22 in such a way, that the motors will operate synchronously.
  • the shaft I6' of the motor I5 carries a plate II' provided with a record and identical to the plate II of the device I 4 at the sending station A.
  • the phonograph record is picked up at two points I8' and I9', the effective positions of which being spaced apart from each other the same distance as the positions of the points I8 and I9.
  • the phonograph transmitters I8' and I9 are connected to each other and to the circuit Q28', which in turn is connected to the winding
  • the transmitters produce a compensating alternating current in the circuit 20', and the shape of curve of said compensating current is equal to the shape o ⁇ fcurv'e of the distorting current.
  • connection of the circuit 20 to the Winding 30 of the transformer I3 is made in such a way, that the phase of the compensating current superimposed on the arriving distorted current by the transformer I3' is displaced at an angle of 180 with respect to the phase of the distorting current.
  • the receiver I2! connected to the transformer I3 through the circuit I I will respond only t ⁇ o the telephonic variations transmitted from the microphone I2 of the sending station A.
  • the distorted currents in the transmission line II are entirely unintelligible to anyone who might have access to the line I8.
  • the station A may also be equipped with a receiver and the station B with a transmitter, by a simple supplement of thewire connections, so that each of both stations forms a sending and receiving station.l Furthermore,
  • the microphones andy receivers may be replaced by telegraph keys and recorders respectively, so
  • the metallic transmission line I l may be replaced by any wireless transmission system.
  • The. relative effective positions of the picking ⁇ up points I8, I8 and ⁇ I8 and I9 to eachother may be adjusted) according to a certain key agreed between the two stations.
  • the relative leffective positions of said picking up points I8, I 9 and I8', I9' to each other are continuously varied "in synchronism with the movement of the phonograph records during the operation. .l
  • FIG. 1 shows the usel of a single phonopersons is impossible, even if the phonograph records used would be known. It is obvious that also ay single phonograph record with three or even more picking up' points or several phonograph records with one or several picking up points may be used to produce the distorting and compensating currents respectively.
  • the records to be used may be either of the nite type, such as a usual phonograph record, or of the endless type, such as a plate with an endless record curve 24 (Fig. 3) or an endless band with a record curve.
  • the endless type such as a plate with an endless record curve 24 (Fig. 3) or an endless band with a record curve.
  • it may be advisable to use a single record of the endlessy type with a single picking up point at eachmoi' the stations and such an arrangement has yet the advantage that the adjustment of the synchronism of the records at the stations is considerably facilitated in comparison with the records of the finite type as hitherto used.
  • the means carrying the records maybe formed by an iron disc provided with an irregularly serrated circumference and rotated in a magnetic eld or by phonograph records or endless bands. which have a record.
  • a plate of transparent material provided with a record is employed, which allows the record curve to be picked up by a photo-electrical ray.
  • Fig. 3 shows' such a glass plate 25 carrying on its surface a photographic emulsion layer, on which a complicated distorting noise is recorded by means of the so-called transverse method
  • Fig. 4 illustrates diagrammatically the arrangement of such a transparent plate in a photoelectrical device.
  • A'light source 25 is arranged in front of the glass plate 25 mounted on the shaft I6 of the motor I5, and a photo-sensitive cell 2Iy is disposed behind the rotating glass plate 25.
  • the record, 24 disposed on the plate 25, is lighted by the light source 26, and the photosensitive cell 21 receives the light rays passed through the record and transforms the same into electrical currents led to the circuit 28.
  • 'I'here are three gaps I, 2, and 3 shown in' Fig. 3 through which light rays may pass to photo-sensitive cells correspondingly arranged, behind the plate 25, so that the records .24 are picked up at three points by photo electrical ray.
  • the phonograph records I'I are replaceably arranged on the shaft I6, so that at different times,
  • Endless phonograph records are rotated with such a number of revolutions, that the fundamental frequency resulting from the number of ldifferent phonograph records may be employed.
  • Suitable adjusting devices may be provided, by means of which at the receiving station, the desired synchronism may be established, after the movement of 'the phonograph'record has been started.
  • the intensity of the distorting alternating currents may be determined by controlling means being independent of 'frequency Furthermore, any line distortions, to which the distorting alternating current is subjected, may be eliminated at the receiving station byso-called artificial lines or combinations of ohmic capacities and inductive re- 20 sistances, which are connected in the circuit of the compensating alternating current.
  • an important feature of my new method is that the shape of curve of the produced distorting or compensating current is lentirely different from the shape of curve of the phonograph record or phonograph records used.
  • the shapeof curve of the produced current will be always a function of a plurality of points of the curve of the phonograph record or
  • the resultant phonograph records may be different for each operation, although the same phonograph record or phonograph records are used, if the relative effective positions of the picking up points will. vbe changed.
  • a transmission system for maintaining secrecy in the transmission of messages between a sending station and a ⁇ receiving station by distorting the outgoing message currents by superimposing thereon at the sending station a distorting alternating current and by neutralizing the effect of said superimposed current at the receiving station by superimposing on the distorted current at the receiving station a compensating alternating current opposite in 'phase to the distorting current, comprising at each of said stations, means including a phonograph record, and
  • a plurality of photo-electrical pickups adapted to secrecy in the transmission of messages between a sending station and a receiving station by distorting the outgoing message currents by superimposing thereon at the sending station a distorting alternating current and by neutralizing the eiect of said superimposed current at the receiving station by superimposing on the distorted current atthe receiving station a compensating alternating current opposite in phase to the distorting current, comprising at each of said stations, means includi'ng a phonograph record, a plurality of pickups adapted to pick up said phonograph record at a plurality of places thereon to produce said distorting and compensating currents respectively, and means for simultaneously varying the relative effective positions of said places to each other.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Optical Communication System (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)
US663574A 1933-01-20 1933-03-30 Transmission system Expired - Lifetime US2083653A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE401564X 1933-01-20

Publications (1)

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US2083653A true US2083653A (en) 1937-06-15

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US663574A Expired - Lifetime US2083653A (en) 1933-01-20 1933-03-30 Transmission system

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US (1) US2083653A (cs)
GB (1) GB401564A (cs)
NL (1) NL37013C (cs)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2466390A (en) * 1944-03-30 1949-04-05 Bell Telephone Labor Inc Secret telegraph system
US2476337A (en) * 1943-01-22 1949-07-19 Sperry Corp Secret radio communication
US2521690A (en) * 1945-08-14 1950-09-12 Standard Telephones Cables Ltd Secrecy preserving signaling system
US2556677A (en) * 1946-05-10 1951-06-12 Bell Telephone Labor Inc Secret communication system
US2660666A (en) * 1950-01-05 1953-11-24 Westinghouse Electric Corp Secrecy transmission system
US3067280A (en) * 1959-09-15 1962-12-04 Teleprompter Corp Secret signaling
US3071752A (en) * 1958-01-02 1963-01-01 Strasberg Murray Interference reduction apparatus
US3887772A (en) * 1944-06-30 1975-06-03 Bell Telephone Labor Inc Signal privacy with safety feature

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE767395C (de) * 1936-05-03 1952-07-31 Lorenz A G C Verfahren zur Geheimhaltung von Nachrichten
DE1087637B (de) * 1959-04-17 1960-08-25 Siemens Ag Schaltungsanordnung zum Verringern der Erkennungsmoeglichkeit von Klartextimpulsen bei einer Fernschreibanlage fuer verschluesselten Betrieb

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2476337A (en) * 1943-01-22 1949-07-19 Sperry Corp Secret radio communication
US2466390A (en) * 1944-03-30 1949-04-05 Bell Telephone Labor Inc Secret telegraph system
US3887772A (en) * 1944-06-30 1975-06-03 Bell Telephone Labor Inc Signal privacy with safety feature
US2521690A (en) * 1945-08-14 1950-09-12 Standard Telephones Cables Ltd Secrecy preserving signaling system
US2556677A (en) * 1946-05-10 1951-06-12 Bell Telephone Labor Inc Secret communication system
US2660666A (en) * 1950-01-05 1953-11-24 Westinghouse Electric Corp Secrecy transmission system
US3071752A (en) * 1958-01-02 1963-01-01 Strasberg Murray Interference reduction apparatus
US3067280A (en) * 1959-09-15 1962-12-04 Teleprompter Corp Secret signaling

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Publication number Publication date
NL37013C (cs)
GB401564A (en) 1933-11-16

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