US2391082A - Telegraph code recorder - Google Patents

Telegraph code recorder Download PDF

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Publication number
US2391082A
US2391082A US521901A US52190144A US2391082A US 2391082 A US2391082 A US 2391082A US 521901 A US521901 A US 521901A US 52190144 A US52190144 A US 52190144A US 2391082 A US2391082 A US 2391082A
Authority
US
United States
Prior art keywords
tube
signals
cathode
negative
resistor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US521901A
Other languages
English (en)
Inventor
Beste Harold Edward
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Allen B du Mont Laboratories Inc
Original Assignee
Allen B du Mont Laboratories Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Allen B du Mont Laboratories Inc filed Critical Allen B du Mont Laboratories Inc
Priority to US521901A priority Critical patent/US2391082A/en
Priority to GB20959/44A priority patent/GB585433A/en
Application granted granted Critical
Publication of US2391082A publication Critical patent/US2391082A/en
Priority to FR939083D priority patent/FR939083A/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L15/00—Apparatus or local circuits for transmitting or receiving dot-and-dash codes, e.g. Morse code
    • H04L15/24—Apparatus or circuits at the receiving end
    • H04L15/28—Code reproducing apparatus

Definitions

  • This invention relates to a device by means of which telegraph code signals are received in such a way that they can be observed visually.
  • received telegraph signals are caused to turn on and deflect the beam or ray of a cathode ray tube to different extents in accordance with the reception of dots and dashes so that traces of different lengths appear on the screen corresponding to the dots and dashes and can be easily observed and the message thereby read.
  • the received dot and dash signals which consist of high frequency oscillations are converted into direct current signals which deflect the beam and at the same time these dots and dashes are utilized to turn on the beam at the proper times so that the different signals canbe read visibly and distinguished from each other.
  • the danger of burning the screen of the cathode ray tube is obviated.
  • reference character I indicates the primary of a transformer to which the output of the usual telegraph code receiver, indicated at a and b as a dash and dot, respectively, is applied.
  • the ends of the secondary 2, 2' are connected to plates of triodes 3 and 4 and these secondaries are tuned by capacitors 5 and 6 to the frequency of the signals a and b which may, for example, be 5 kc.
  • the center point of the secondaries 2, 2' and a point between capacitors 5, G' are connected to a source of negative potential, say 250 volts as indicated at l9.
  • the signals a and b produce negative direct current signals and d which are the outputs of triodes 3 and 4. These signals are filtered by the RC filter 8, 9, I0, which has a short time constant, to remove the high frequency components and leave the negative polarity direct current signals e, I which are applied to the grid of triode' l2.
  • the plate of this triode is connected to ground through resistor l3 and its cathode is connected to the source of negative potential indicated at IS.
  • the cathode of this tube I is connected by an adjustable contact to a potentiometer l6 one end of which is connected to a. source of direct current and the other to ground.
  • a capacitor I8 is connected between the plate and cathode of tube l2.
  • in series are located be- ,tween the negative source of potential is and ground 25.
  • Resistors 22 and 23 in series are located between a positive source of potential 24 and ground 25.
  • a lead 28 extends from a point between resistors 20 and 2
  • a sliding contact on resistor 21 is connected by lead 29 to the control grid 30 of a cathode ray tube T.
  • of this tube is connected through resistor 32 to ground and by lead 33 to the grid of triode l2.
  • the positive potential applied at 24 is coupled by lead 34 and connector 35 to the anode 36 of tube T, and by connector 31 to the focussing coil 38 of thistube T which is in turn connected by an adjustable resistor 38 to ground.
  • for the beam of the cathode ray tube T are connected in eries from lead 34 to the plate of tube l5.
  • the signals consisting dashes and dots made up of say 5 kc. frequency oscillations as indicated at a. and b are applied to the primary l of the transformer.
  • the output of the secondaries 2 and 2' of this transformer is applied alternately to the plates of tubes 3 and 4 and appears as rectified direct current signals with negative polarity modulated by 5 kc. frequency as shown at c, d.
  • This output is filtered by filter 8lll to remove the high frequency components and yield the signals e, j which are applied to the grid of tube l2.
  • the resistor l3 applies a positive voltage to the anode of tube l2 with respect to the negative voltage applied at l9 that is connected to its cathode, thus causing current to fiow from ground through resistor l3 and tube [2 to the negative terminal l9 during the time no signal is applied to the primary l of this transformer.
  • the capacitor I8 is not charged appreciably during this time because the internal resistance of tube I2 is small compared to the high resistance at l3 when it is drawing current and therefore there is only a small potential at the plate of tube 12.
  • said means as follows: comprising an amplifying circuit tuned to said The lead 33 applies the rectangularly shaped oscillations and adjust d to yield rectans r 8 ssignals e, f to the cathode SI of tube '1 in negative nals, means to convert said rectangular signals polarity and the grid ll of this tube is biased into A-shapedsignals correspondinginamplitude negatively a sumcient amount by adimtment of 16 to the lengths of said rect n ular si na s.
  • Bald heped signals to said deflection tensity of the beam of tube T when no signal is system mean to cause said rectangular signals applied.
  • f voltage to turn on the ray of said cathode-raytube for is applied to the cathode Ii it biases this cathperiods of time in accordance with the lengths of ode Si in a negative direction to such an extent 90 said rectangular signals, and means to produce as to form the beam which is accelerated by anode I6 and strikes the screen of the tube '1 simmtaneously with the passing of current through the cells 40, 4
  • the tube can be rotated fast enough so that enough characters to make up several words within the are relative rotation between said cathode-ray tube and its beam.
  • said first named means comprises a transformer and a high frequency filter to filter out said high frequency oscillations.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Measurement Of Radiation (AREA)
  • Details Of Television Scanning (AREA)
US521901A 1944-02-11 1944-02-11 Telegraph code recorder Expired - Lifetime US2391082A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US521901A US2391082A (en) 1944-02-11 1944-02-11 Telegraph code recorder
GB20959/44A GB585433A (en) 1944-02-11 1944-10-27 Telegraph code recorders
FR939083D FR939083A (fr) 1944-02-11 1946-04-01 Appareils télégraphiques et analogues

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US521901A US2391082A (en) 1944-02-11 1944-02-11 Telegraph code recorder

Publications (1)

Publication Number Publication Date
US2391082A true US2391082A (en) 1945-12-18

Family

ID=24078612

Family Applications (1)

Application Number Title Priority Date Filing Date
US521901A Expired - Lifetime US2391082A (en) 1944-02-11 1944-02-11 Telegraph code recorder

Country Status (3)

Country Link
US (1) US2391082A (fr)
FR (1) FR939083A (fr)
GB (1) GB585433A (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2644105A (en) * 1952-01-30 1953-06-30 Motorola Inc Television circuit
US2711494A (en) * 1951-10-16 1955-06-21 Everett C Westerfield Signal-averaging electronic circuit
US2797316A (en) * 1950-06-25 1957-06-25 Int Standard Electric Corp Circuit arrangement generating sawtooth current waves
US3123775A (en) * 1964-03-03 leeds

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3123775A (en) * 1964-03-03 leeds
US2797316A (en) * 1950-06-25 1957-06-25 Int Standard Electric Corp Circuit arrangement generating sawtooth current waves
US2711494A (en) * 1951-10-16 1955-06-21 Everett C Westerfield Signal-averaging electronic circuit
US2644105A (en) * 1952-01-30 1953-06-30 Motorola Inc Television circuit

Also Published As

Publication number Publication date
GB585433A (en) 1947-02-06
FR939083A (fr) 1948-11-03

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