US1426944A - Radiosignaling system - Google Patents

Radiosignaling system Download PDF

Info

Publication number
US1426944A
US1426944A US189495A US18949517A US1426944A US 1426944 A US1426944 A US 1426944A US 189495 A US189495 A US 189495A US 18949517 A US18949517 A US 18949517A US 1426944 A US1426944 A US 1426944A
Authority
US
United States
Prior art keywords
amplitude
current
pulsations
receiving
messages
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
US189495A
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 US189495A priority Critical patent/US1426944A/en
Priority to FR506988A priority patent/FR506988A/fr
Application granted granted Critical
Publication of US1426944A publication Critical patent/US1426944A/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
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/02—Channels characterised by the type of signal
    • H04L5/06—Channels characterised by the type of signal the signals being represented by different frequencies

Definitions

  • My present invention Arelates to-radio signaling systems and comprises both transmitting and receiving apparatusifor use in4 such systems.
  • One ofthe objects of my invention is to provide a system of multiplex "signaling in whichl a plurality .of messages may be transmitted and received simultaneously by the use of a single wave length.
  • a second ⁇ object of my invention is to provide a systemgfor transmitting and receiving messages which is arranged in such a way that it will be practically impossible for another station to interfere Awith the eiicient -transmission and reception of the de-l sired messages.
  • Still another object of my invention is to.
  • asource of continuousv radio frequency current such, for example, as a high frequency alternator, an arc generator' or/an electron discharge oscillator.
  • a magnetic amplifier of the general type described in my prior Patent #1,206,643.
  • the amplitude I employ, i
  • pulsations produced in the fundamental wave willbe the resultant orcombination of the amplitude pulsations produced by the several different frequencies employed.
  • the low frequency currents are o f sine wave form.
  • the' resultant amplitude pulsations wlll be proportional to the sum of the several sine waves employed.
  • an antenna may be employed, which is tuned to the frequency of the source of supply.
  • a secondary receiving circuit may be employedl for each message, each secondary circuit being tuned to the particular frequency of the amplitude pulsations which are employedfor transmitting the message to be received in that circuit. In this way f the resultant wave produced by the combination ofthe amplitude pulsations of'several different frequencies may be resolved into its priginal low frequency components.
  • the message maybe transmitted simultaneously by means of amplitude pulsations of several different frequencies.
  • the receiving operator may be provided with means for receivingr the message at any one of the amplitude pulsation frequencies transmitted.
  • it would be necessary .for a disturbing station to set up a wave having amplitude pulsations of the same nature as those produced by the transmittingystation This would be prac- -regular order.
  • the receiving instrument In order to receive a message transmitted in thisv way, it will be necessary that the receiving instrument be connected successively in the same order to circuits tuned to the different frequencies used for ⁇ producing the amplitude pulsations.
  • FIG. 3 ⁇ shows a transmitting circuit which may beV used 'for preventing interference
  • lig. 4 shows a receiving circuit for the system shown in'Fg. 3
  • Fig. 5 shows a transmitting circuitwhich may be used toinsure secrecy
  • Fig. 6 shows a receiving circuit forthe system shown in Fig. 5.
  • the antenna 1 is supplied with radio frequency current from any convenient source.
  • the high frequency alternator 2 may be drive-n by a direct current motor 4 mounted. upon the same shaft 5 and supplied with.k
  • the secondary -7 of transformer 3 is a magnetic amplifier comprising a ⁇ suitable core 8 of magnetic material and'two windings'9 and 10 as indicated. These windings are so arranged that the high frequency current supplied by vsecondary 7 iiows through the'two windings 9 and 10 )in parallel and that. the flux produced by 4this current flows in opposite directions through the'portions 11 'and l2 of the core 8.
  • the current for controlling the magnetic amplifier may conveniently be obtainedfrom spect to the high frequency source and hence,
  • alternators 19, 20, and 21 there may be mounted three alternators 19, 20, and 21. Iloles 22, 23 and 24 yof these alternators are connected directly to the circuit which supplies direct sage transmitted by key 28 will bc transmitted by means of amplitude pulsations having a frequency of 800. Simultaneously a sec-",100 ondmessage may be transmitted by key 29 .by means of amplitude pulsations having a frequency of 700, and a thirdmessage may be transmitted by key B0 by means Aof aml l plitude pulsations having a frequency of 600.
  • the currents supplied by the alternators 19, 20 and'21 should, preferably be of sine wave form in order Vthat the amplitudev pulsations produced may be of a harmonic nature.
  • the system whichI have described will preferably be so adjusted that when none of thekeys are depressed, about half of the current from the antenna will iow through the windings 9V and 10, and the amplitude of the current flowing in the antenna will be about. 1151 half of the maximum. j When one or more keys are depressed, the controlling current varies and the radio frequency current in windings 9 and 10 will varyaccordingly.
  • Fig. 2 I have indicated a'simple form of receiving system which may be used for receiving upon asingleantenna all of the' messages transmitted by means of the system shown in Fig. l;
  • the wave having amplitude pulsations may be received upon the antenna 34, which is-tuned to the frequency of the source 2.
  • the received waves are imL pressed uponV the resonant grid circuit.of the electron discharge usual manner, as indicated.
  • the amplitudel pulsations of the different vmessages correspond to these frequencies.
  • the coupling may be made through condensers 49, 50 and 51 and receivers, l52,
  • the 'received signal is t0 be rendered audible 'the' frequency employed for the ⁇ amplitude pulsations Willpreferably be within' the range of audio frequencies, and since the necessary difference between any two of the frequencies employed may be even less than the 100 rcycles which Vis given' in the above eXam le, it is apparent that a large number of iferent messages may be transmittedsimultaneously by a single wave employ a receiver in which the signal vgives a visible'indication, frequencies lower than audio frequencies may be employed for producing amplitude pulsations. It will also be vamplifier 35 in thev length. 'In case it is desired to apparent-that amplitude pulsations o f ultra audible frequencies may also be utilized if desired.
  • the system which I have described may also be convenientlyv modified for efficienttransmission of messages to different stations located at different distances from the transmittin station.
  • the messages ⁇ or the nearer station or stations may bev transmitted by amplitude pulsations of a small amount, while the messages for the more distant stations may be transmitted by amplitude pulsations of greater magnitude.
  • This effect maybe obtained by thenuse of variable resistances 55, 56 and 57 in series with the keys 28, 29 and 30 whereby the current flowing through each key may be adjusted independently of the others.
  • a single key 55 is substituted for the three keys of Fig. 1 so that when this key is operated, amplitude pulsations of three diferent frequencies are produced in the antenna current.
  • the message transmitted may be received-by turning the receiving apparatus to any one of the amplitu'de pulsation frequencies employed for transmission.
  • a foreign station sends out a disturbing Wave which prevents the operator from receiving the message at one frequency, he may change over toah.- other frequency for receiving, and unless the disturbing station was informed of all of the different frequencies employed for pro- -ducing amplitude pulsations, it would be practically impossible for it to send out a wave which would interfere with reception at all 'of the different fre uencies employed.
  • Fig. 4 I have indicate a convenient arrangement' for receiving, in which a single receiver 56 is employed and a switch 57 is provided, whereby the receiving operator can quickly change from one receiving circuit to another.
  • Fig. 5 I have indicated a transmitting system which is especially adapted for sending messages in such 'a way that they can be received only' ⁇ by a desired station.
  • each message instead of being transmitted by means of amplitude pulsations of a definite frequency, is transmitted by means of amplitude pulsations of different frequenc'ies coming one after another in a prearranged regular order.
  • the brushes 25, 26, and 27 may be connected by means of brushes 58, 59, and 60, to three slip rings 61, 62 and 63 respectively.
  • each ring is arranged to ⁇ rotate together -and each ring is'connected to a segment of 4a fourth ring made u of three segments insulated from each ot er.
  • the different receiving circuits may ,be connected atrthe proper time to the right receiving instrument for receiving each message. It will be apparent that in order to receive a message which is sent in this way, the receiving operator must know the order in which the different amplitude pulsations succeed each other, the frequency of each set andthe speed at which the revolving rings are driven. It would be practically impossible for anyone who was unaware of these factors to'v receive-any one of the messages transmitted.
  • the method of controlling the current i in an antenna supplied withV a source of continuous radio frequency current and having a magnetic amplifier associated therewith which consists in simultaneously supplying to the windings of said amplifier control-ling currents of a plurality of diderent frequencies, all of which are of a frequency lower than that of the source, and thereby producing amplitude pulsations of a. plurality of different frequencies in the current in said. antenna and transmitting a single signal thereby which may be received by selecting any desired one of the different frequencies of amplitude pulsations.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Selective Calling Equipment (AREA)
  • Mobile Radio Communication Systems (AREA)
US189495A 1917-09-04 1917-09-04 Radiosignaling system Expired - Lifetime US1426944A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US189495A US1426944A (en) 1917-09-04 1917-09-04 Radiosignaling system
FR506988A FR506988A (fr) 1917-09-04 1919-04-14 Perfectionnements aux systèmes de radio-signalisation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US189495A US1426944A (en) 1917-09-04 1917-09-04 Radiosignaling system

Publications (1)

Publication Number Publication Date
US1426944A true US1426944A (en) 1922-08-22

Family

ID=22697573

Family Applications (1)

Application Number Title Priority Date Filing Date
US189495A Expired - Lifetime US1426944A (en) 1917-09-04 1917-09-04 Radiosignaling system

Country Status (2)

Country Link
US (1) US1426944A (fr)
FR (1) FR506988A (fr)

Also Published As

Publication number Publication date
FR506988A (fr) 1920-09-02

Similar Documents

Publication Publication Date Title
US2461456A (en) Frequency shift keying
US2272839A (en) Radiant energy signaling system
US2607004A (en) Radio transmission system
US1987889A (en) Means for elimination of fading on short wave lengths
US2245717A (en) Wave indicating system
US1426944A (en) Radiosignaling system
US1935776A (en) Side band reversal transmission system
US2459281A (en) Two-way radio equipment for lifeboat service
US1814813A (en) Radio signaling system
US2288802A (en) Signaling system
US1607158A (en) System eor the transmission and reception of radiant energy
US2312093A (en) Radiant energy signaling system
US1875165A (en) Method for wireless communication
US2025190A (en) Multiplex signaling
US1816579A (en) Radio communication system
US1309459A (en) Wireless signaling system
GB695901A (en) Improvements in or relating to telegraph receivers
US1766050A (en) Multiphase cornet system
US2521690A (en) Secrecy preserving signaling system
US1961206A (en) Twelve-course, aural type, triple modulation directive radiobeacon
US1690719A (en) Emqby leon chaj
US2895009A (en) Channeling system for frequency spectrum transmission
US2127525A (en) Radio receiving system
US1491776A (en) Selective-wave transmission system
US1528032A (en) Selective signaling system