US1500785A - High-frequency signaling system - Google Patents

High-frequency signaling system Download PDF

Info

Publication number
US1500785A
US1500785A US496229A US49622921A US1500785A US 1500785 A US1500785 A US 1500785A US 496229 A US496229 A US 496229A US 49622921 A US49622921 A US 49622921A US 1500785 A US1500785 A US 1500785A
Authority
US
United States
Prior art keywords
current
high frequency
sources
circuit
transmitting circuit
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
US496229A
Other languages
English (en)
Inventor
Ernst F W Alexanderson
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.)
General Electric Co
Original Assignee
General Electric Co
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 General Electric Co filed Critical General Electric Co
Priority to US496229A priority Critical patent/US1500785A/en
Priority to GB1026/22A priority patent/GB196062A/en
Priority to FR555438D priority patent/FR555438A/fr
Application granted granted Critical
Publication of US1500785A publication Critical patent/US1500785A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/10—Frequency-modulated carrier systems, i.e. using frequency-shift keying

Definitions

  • H is Attor n ey.
  • the usual telegraphic code employed for transmitting messages by means of electric currents is made up of two principal characters differing from one another only in their time interval, a dot representing a time interval about half. that of a dash. It is evident, therefore, that by reason of this fact a longer time is required for the transmis sion ofa message than would be the case if all characters were represented by the smaller time interval required for the transmission of a dot.
  • a more specific object of my invention is to provide a method of and a paratus for signaling which will permit 0 a reduction of the time required for transmission of a message by allowing for the same time interval for both dots and dashes.
  • my invention 1 provide two sources of high frequency current, such for example, as two high frequency alternators of different frequency and connect both of these sources to the antenna. I also provide means for practically short circuiting at will either one of these sources so that the other source alone will supply energy to the antenna. In; addition I provide controlling means which is arranged in such a way that when one of the sources is short circuited the tuning of the antenna is changed so that the antenna becomes resonant for the frequency of the other source which is supplying energy to the antenna at that instant. v
  • Fig. 1 shows diagrammatically the application of my' invention to a radio transmitting system
  • Fig. 2 shows a receiving system for receiving and recording the message transmitted
  • Fig. 3 shows a modification in the method of transmitting the message.
  • I provide two sources of high ferquency current 1 and 2 which are connected by means of transformers 3 and 4 to a transmitting circuit which in the present case is indicated as an antenna 5, altho it may equally well be a wire line if d ired.
  • I provide a magnetic amplifier having high frequency windings 6 and the usual series condensers 7 and S. Current for saturating. the core of the magnetic amplifier is supplied to the saturation winding 9 from a source 10 of direct current by means of a key 11.
  • the current supplied to the antenna 5 by the connections indicated will vary in inverse proportion to the amount of current supplied to the saturation winding 9.
  • the current in saturation winding 15 is interrupted thereby removing the short circuit from source 2 and permitting radiation from that source to take place.
  • the current in saturation winding 9 is interrupted thereby removing the short circuit from source 1 and permitting radiation from that source'to take place.
  • the tuning of the antenna When source 1 is radiating, the tuning of the antenna will be determined chiefl' by the loading coil 18, the inductance o the transformer 3 and the inductance of the high frequency windings 12 of the magnetic amplifier associated with source 2, the inductance of these windings at this time being small in comparison with the inductance of the transformer 4.
  • the high frequency windings of the amplifier associated with source 1 may be connected to an intermediate point 19 in the loading coil 18.
  • the tuning of the antenna will then be determined by the portion of the loading coil above point 19, the inductance of windings 6 and the inductance of transformer 4.
  • the current transmit-ted may be received upon an antenna 23 and supplied t the usual tuned receiving circuits 24 and 25 which are tuned respectively to the two frequencies of sources 1 and 2 and which are associatedwith detectors 26 and 27.
  • the plate circuits of these detectors may be inserted windings 28 and 29 of a relay having a movable armature 30, the movement of which is controlled two sources of high frequenc by either of the two windings.
  • the armaergy is radiated from source 2 the detector 27 will operate and coil 29 will attract the armature 30, making indications 33 representing dashes on the tape.
  • a further shortening of the time required for transmission may be efiected by reducing the time interval between the successive characters of a letter.
  • I have indicated an interval between successive characters which is small in comparison with the time required to transmit a dot. This interval is so small that the armature 30 does not have time to return to its normal central position between successive characters of a letter. Na difiiculty will be experienced in reading the message record-ed however, as
  • the number of successive dots or dashes can readily be observed from the small waves in the record line or from the space interval occupied on the tape by the'characters of a letter.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Near-Field Transmission Systems (AREA)
US496229A 1921-08-29 1921-08-29 High-frequency signaling system Expired - Lifetime US1500785A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US496229A US1500785A (en) 1921-08-29 1921-08-29 High-frequency signaling system
GB1026/22A GB196062A (en) 1921-08-29 1922-01-12 Improvements in and relating to high frequency signalling systems
FR555438D FR555438A (fr) 1921-08-29 1922-08-28 Perfectionnements aux systèmes de signalisation à haute fréquence

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US496229A US1500785A (en) 1921-08-29 1921-08-29 High-frequency signaling system

Publications (1)

Publication Number Publication Date
US1500785A true US1500785A (en) 1924-07-08

Family

ID=9714839

Family Applications (1)

Application Number Title Priority Date Filing Date
US496229A Expired - Lifetime US1500785A (en) 1921-08-29 1921-08-29 High-frequency signaling system

Country Status (3)

Country Link
US (1) US1500785A (fr)
FR (1) FR555438A (fr)
GB (1) GB196062A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2486511A (en) * 1945-10-31 1949-11-01 Rca Corp Apparatus for receiving facsimile signals
US2869116A (en) * 1954-01-28 1959-01-13 Mackay Radio & Telegraph Co Automatic keyer for lifeboat radio equipment

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1086762B (de) * 1957-11-08 1960-08-11 Telefunken Gmbh Senderschaltung mit Mitteln zur Frequenzmodulation und mit schwach gedaempftem Antennenkreis

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2486511A (en) * 1945-10-31 1949-11-01 Rca Corp Apparatus for receiving facsimile signals
US2869116A (en) * 1954-01-28 1959-01-13 Mackay Radio & Telegraph Co Automatic keyer for lifeboat radio equipment

Also Published As

Publication number Publication date
GB196062A (en) 1923-04-12
FR555438A (fr) 1923-06-29

Similar Documents

Publication Publication Date Title
US2231806A (en) Radio apparatus
US2385673A (en) Carrier current system
US1500785A (en) High-frequency signaling system
US2047900A (en) Multiple signaling system
US1970424A (en) High frequency signal system
US2357398A (en) Transmitter having impulse modulation
US2131109A (en) Radio telegraph receiving system
US2254342A (en) Receiver selection system
US1596251A (en) Secret radiant telephony
US1886263A (en) Multiplex communication system
US1753353A (en) Electrical system for secret transmission
US1573303A (en) Carrier-wave transmission
US1461783A (en) Secret-communication system
US1416061A (en) Radioreceiving system having high selectivity
US1717062A (en) Electric signaling
US1801774A (en) Radio signaling system
US1747221A (en) Automatic selection of receiving channels
US1460438A (en) Secret-communication system
US818363A (en) Art of signaling through space.
US2468574A (en) Selective control of printer motors at outlying telegraph stations
US1705211A (en) Radio telegraph system
US1171813A (en) Multiplex telegraphy.
US749370A (en) Wireless signaling system
US1718794A (en) Selective and antiparasitic receiving system
US1739384A (en) High-frequency signaling system