US1941069A - Radiosignaling - Google Patents

Radiosignaling Download PDF

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Publication number
US1941069A
US1941069A US653237A US65323733A US1941069A US 1941069 A US1941069 A US 1941069A US 653237 A US653237 A US 653237A US 65323733 A US65323733 A US 65323733A US 1941069 A US1941069 A US 1941069A
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United States
Prior art keywords
frequency
cycles
amplitude
disturbances
variations
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Expired - Lifetime
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US653237A
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English (en)
Inventor
Edwin H Armstrong
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Individual
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Individual
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First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=24620034&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US1941069(A) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority to BE433916D priority Critical patent/BE433916A/xx
Priority to NL44760D priority patent/NL44760C/xx
Application filed by Individual filed Critical Individual
Priority to US653237A priority patent/US1941069A/en
Publication of US1941069A publication Critical patent/US1941069A/en
Application granted granted Critical
Priority to GB2436/34A priority patent/GB426228A/en
Priority to FR771091D priority patent/FR771091A/fr
Priority to GB2435/34A priority patent/GB426227A/en
Priority to DEA2624D priority patent/DE924809C/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B14/00—Transmission systems not characterised by the medium used for transmission
    • H04B14/002—Transmission systems not characterised by the medium used for transmission characterised by the use of a carrier modulation
    • H04B14/006—Angle modulation
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03C—MODULATION
    • H03C5/00—Amplitude modulation and angle modulation produced simultaneously or at will by the same modulating signal

Definitions

  • This invention relates to a method of increasing the distance of transmission which may be covered in radio signaling with very short Waves.
  • the electrical disturbances which are created in the rst tube in a chain of vacuum tube amplifiers, when amplified by the chain and supplied to the detector are great enough to mask the effect of the signal when it falls below a certain level.
  • the nature of the disturbance which is due mainly to the irregularities of the electron emission from the filaments of the vacuum tubes, is that of a spectrum, containing all frequencies, and as is well known it manifests itself in the telephone by a high pitched hiss, the frequencies composing which run from some low value to above audibility.
  • the combination of all the irregularities of emission produces a spectrum of radio frequency currents which consists of irregular variations in amplitude and also, as I have found, in frequency, so that the hiss is heard in a frequency modulation receiver as well as in the ordinary type of receiver for amplitude modulated waves. This occurs even when the amplitude modulations of the disturbing currents are eliminated by current limiting or by some equivalent process.
  • Fig. l illustrates the general arrangement of the transmitter, Fig. 2 the arrangement of the receiver and Figs. 3, 4 and 5 the characteristics of reception of the arrangement of Fig. 2.
  • Fig. 1 is shown a modulating system similar in principle to that described in my application filed of even date herewith.
  • 1 represents a constant frequency oscillator
  • 2 an amplifier of the output of this oscillator with a resistance 3 in its plate circuit which is small in comparison with the impedance of the tube.
  • 4 and 5 are likewise amplifiers of the currentproduced by the master oscillator 1.
  • 6 is a transformer for dif'- 95 ferentially modulating the plate voltages of the tubes 4 and 5 by the signaling current which is applied to the primary of the transformer through the amplifying system 26, 29, 31.
  • 7 and 8 are condensers shunting the two halves of the secondary of the transformer 6, and 9 and 10 are inductances whose impedance for the frequency of the oscillator is small compared to the impedance of the tubes 4 and 5.
  • 11 is a small induct- 105 ance whose natu-ral frequency is high compared to the frequency of the oscillator. It is coupled differentially to the coils 9 and 10.
  • /12 is an vampliiiei" for amplifying the outputs of the tubes 4 and 5. Its plate is connected as shown to an 110 adjustable point in the resistance of the plate circuit of the amplifier 2.
  • the combined outputs of the tubes 2 and 12 are supplied to an amplier 15, 16 whose output passes through a current limiter 17, lter 18 and to a frequency multiplier 19 of many stages, power amplifier 20 and antenna 22.
  • 27, 28 represents a correction system for impressing on the input, of the amplifier 29 a voltage inversely proportional to the frequency of modulation which is applied at 25.
  • Fig. 2 which represents a receiving system
  • 35, 36 represent the antenna system.
  • 37 represents an amplifier for the frequency of the received wave.
  • 38 represents a rectifier and 39 an oscillator for heterodyning the output of the amplifier 37 to a lower value which is amplified in the amplifier 40.
  • 4l, 42 represents a rectifier and oscillator for heterodyning the output of the amplifier 40 down to a still lower intermediate frequency and 43 represents an amplier for this second intermediate frequency.
  • 44 represents a current limiter supf plied by the output of the amplifier 43.
  • 45 is a filter through which the output of the current limiter 44 is passed.
  • 46 is a second amplifier similar to the amplifier 43 and 47 is a current limiter for limiting the output of this amplifier.
  • 48 is a filter for the output of the second current limiter 47.
  • 49 is an amplifier for amplifying the limited and filtered output of the amplifier 46.
  • the output of the amplifier 49 is delivered to a selective system consisting of two branch circuits 50, 52, 54 and 51, 53, 55 which are connected respectively to the inputs of the two detectors 56, 57.
  • the plate circuits of these detectors contain transformers 58, 59 which are connected so as to respond cumulatively for frequency variations, but differentially for amplitude variations.
  • 66 is a meter connected across the bridge formed by the resistances 62, 63 for the purpose of indicating the balance point.
  • 60, 61 and 64, 65 are the usual by-pass condensers.
  • 67 is a lter for the purpose of excluding frequencies above the range of the signaling frequencies and 68 is the telephone receiver.
  • Figs. 3 and 4 illustrate the reactance characteristics of the capacity inductance combinations 52, 54 and 53. 55. Characteristic values are taken for a swing of 100,000 cycles between the limits of 150,000 and 250,000 cycles respectively.
  • M represents the reactance characteristic of 52, 54 which is made non-reactive for 150,000 cycles and N the reactance characteristic of 53, whichI is made non-reactive for 250,000 cycles.
  • Fig. 4 illustrates the rectified or plate currents through the resistances 62 and 63 as shown by M and N, and O represents the current through the indicating instrument 66 in the balanced arm of the bridge.
  • the output of the two transformers 58 and 59 are proportional to the current changes indicated by O.
  • Fig. 5 illustrates the action of the system with respect to disturbances and will be referred to in detail later.
  • the operation of the transmitter is similar to that described in my application previously referred to except that in the present arrangement the number of frequency multipliers is increased to an extent which gives a swing many times greater than the audible frequency range.
  • the band width must be twice the frequency of modulation, plus the frequency swing or deviation.
  • the interference manifests itself as a steady hiss in the telephones or speaker and it is quite disturbing even when its amplitude is small compared with the amplitude of the Signal. Electrically it is practically a continuous spectrum. In this it differs from static in that static is an extremely irregular spectrum in which, because of its discontinuous character, the peaks may be commensurate with or greater than the signal before serious disturbance occurs.
  • the action is cumulative.
  • the response cn the side represented by the curve AB is equal to OP-OQ or PQ and on the side represented by CD the response is equal to OS-OR or SR. Since the two detector outputs are connected cumulatively for frequency variations the total response is the sum of the two or PQ-l-SR..
  • the signal by reason of its frequency swing over the range from 150 kilocycles to 250 kilocycles the voltages impressed on the detectors Vary from zero to OM' on one side and from zero to ON on the other side.
  • the total response is, therefore, proportional to the sum of OM' and ON and the improvement in sgnal to hiss ratio is apparent.
  • Figs. 1 and 2 Based on measurements made with the system illustrated in Figs. 1 and 2 with a frequency swing of 100,000 cycles and a transmission frequency of 50,000,000 cycles (6 meters) the disturbances were reduced by this method to less than 1% of the energy of the disturbances in an ordinary amplitude modulated transmitter of equal power.
  • the initial frequency or the frequency of the master oscillator in the transmitter was of the order of 50,000 cycles.
  • Ten stages of frequency doubling was employed.
  • the tuned circuits in these stages were suitably broadened by the introduction of resistance to accommodate the wide variation of frequency. On account of ne' we.”
  • the amplier represented byv 37 consisted of three stages of tuned circuit coupled amplification at 50,000,000 cycles. This was heterodyned down by the rectifier, oscillator combination 38, 39 to about 6,000,000 cycles and amplied by the four stage transformer coupled amplier 40. The output of this amplifier was heterodyned down by the rectifier, oscillator combination 41, 42 to 200,000 cycles. This current was then amplified by a ve stage resistance coupled amplifier arranged to be flat from 150,000 cycles to 250,000 cycles by the proper choice of plate resistances, grid condensers and grid leak resistances. The output of this amplifier is supplied to a current limiter consisting of a screen grid tube operated at less than normal plate and screen grid voltages.
  • the amplier 49 consists of a couple of stages of resistance coupled amplification for the purpose of raising the voltage applied to the grids of detectors 56, 57 (which are biased to cutoff) to a sufficient level to secure straight line rectification.
  • the resistances 50, 51 are of the order of 15,000 to 20,000 ohms and the inductance, capacity combinations 52, 54 and 53, 55 are suitably chosen, one to be non-reactive slightly below 150,000 cycles and the other to be non-reactive slightly above 250,000 cycles, and to have, respectively, the same arithmetic value of reactance at 200,000 cycles.
  • the method of eliminating in radio signaling disturbances having the nature of a spectrum which consists in producing a variation in frequency of the wave to be transmitted substantially greater in extent than the frequency range of good audibility, transmitting such wave, receiving the wave and amplifying the received currents, substantially eliminating amplitude 'variations so as to minimize the noise caused by the amplitude variations due to the disturbances, translating the frequency variations of the received signal into amplitude variations by a selective system which is fully responsive to the Wide variations of the signal, but substantially not responsive to the lesser variations in frequency of the spectrum of the disturbances to be eliminated.
  • a system for eliminating in radio signaling disturbances having the nature of a spectrum comprising means at the transmitter for producing a variation in frequency of the wave to be transmitted, substantially greater in extent than the frequency range of good audibility, means at the receiver for amplifying the received currents, current limiting means for substantially eliminating amplitude variations, and a detector system for translating the frequency variations of the received signal into amplitude variations, said system being fully responsive to the wide variations of the signal but substantially not responsive to the lesser variations in frequency of the spectrum of the disturbances to be eliminated nor to variations in amplitude of said disturbances.

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  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Transmitters (AREA)
  • Noise Elimination (AREA)
  • Circuits Of Receivers In General (AREA)
US653237A 1933-01-24 1933-01-24 Radiosignaling Expired - Lifetime US1941069A (en)

Priority Applications (7)

Application Number Priority Date Filing Date Title
BE433916D BE433916A (fr) 1933-01-24
NL44760D NL44760C (fr) 1933-01-24
US653237A US1941069A (en) 1933-01-24 1933-01-24 Radiosignaling
GB2435/34A GB426227A (en) 1933-01-24 1934-01-24 Improvements in or relating to radio signalling
GB2436/34A GB426228A (en) 1933-01-24 1934-01-24 Improvements in or relating to radio signalling
FR771091D FR771091A (fr) 1933-01-24 1934-01-24 Procédé et installation de radiocommunication
DEA2624D DE924809C (de) 1933-01-24 1934-01-25 Verfahren zur Verminderung spektrumartiger Stoerungen bei der drahtlosen UEbertragung des Hoerfrequenzbandes mittels frequenz-modulierter Hochfrequenz-Schwingungen

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US653237A US1941069A (en) 1933-01-24 1933-01-24 Radiosignaling

Publications (1)

Publication Number Publication Date
US1941069A true US1941069A (en) 1933-12-26

Family

ID=24620034

Family Applications (1)

Application Number Title Priority Date Filing Date
US653237A Expired - Lifetime US1941069A (en) 1933-01-24 1933-01-24 Radiosignaling

Country Status (6)

Country Link
US (1) US1941069A (fr)
BE (1) BE433916A (fr)
DE (1) DE924809C (fr)
FR (1) FR771091A (fr)
GB (2) GB426227A (fr)
NL (1) NL44760C (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE746192C (de) * 1938-11-12 1944-06-19 Aeg Sendeverfahren mit Frequenzmodulation
DE971422C (de) * 1937-11-19 1959-01-29 Int Standard Electric Corp Hochfrequenz-Nachrichtenuebertragungsanlage, bei der die Nachrichten mittels zeitmodulierter Impulse uebertragen werden
DE972138C (de) * 1943-12-31 1959-05-27 Funkstrahl Ges Fuer Nachrichte Anordnung zur Begrenzung der Amplitude von Wechselspannungen, insbesondere von frequenzmodulierten Schwingungen

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE927749C (de) * 1942-05-12 1955-05-16 Studiengesellschaft Fuer Elekt Schaltungsanordnung zur Amplitudenbegrenzung
DE1277375B (de) * 1964-11-06 1968-09-12 Te Ka De Fernmeldeapp G M B H Verfahren zur Frequenzmodulation relativ niedriger Traegerfrequenzen, insbesondere im km-Wellenbereich

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE361387C (de) * 1920-02-28 1922-10-13 Marconi Wireless Telegraph Co Sender fuer drahtlose Telephonie
DE424239C (de) * 1920-08-31 1926-01-22 Siemens & Halske Akt Ges Verfahren zur drahtlosen Hochfrequenztelephonie
US1599586A (en) * 1922-04-27 1926-09-14 John Hays Hammond Jr Radiant signaling system
US1885826A (en) * 1926-12-08 1932-11-01 American Telephone & Telegraph System of photography employing frequency modulation
GB290642A (en) * 1927-05-18 1929-07-18 Edwin Howard Armstrong Improvements in radio telephone signalling
US1941447A (en) * 1927-05-18 1933-12-26 Edwin H Armstrong Radio telephone signaling
US1819508A (en) * 1927-08-11 1931-08-18 Rca Corp Communication by frequency variation
US1872364A (en) * 1927-10-08 1932-08-16 Westinghouse Electric & Mfg Co Radiotransmitting system
US1867567A (en) * 1929-02-01 1932-07-19 Rca Corp Detection of frequency modulated signals
US1917102A (en) * 1929-07-22 1933-07-04 Gen Electric Frequency modulation

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE971422C (de) * 1937-11-19 1959-01-29 Int Standard Electric Corp Hochfrequenz-Nachrichtenuebertragungsanlage, bei der die Nachrichten mittels zeitmodulierter Impulse uebertragen werden
DE746192C (de) * 1938-11-12 1944-06-19 Aeg Sendeverfahren mit Frequenzmodulation
DE972138C (de) * 1943-12-31 1959-05-27 Funkstrahl Ges Fuer Nachrichte Anordnung zur Begrenzung der Amplitude von Wechselspannungen, insbesondere von frequenzmodulierten Schwingungen

Also Published As

Publication number Publication date
BE433916A (fr)
FR771091A (fr) 1934-09-29
GB426227A (en) 1935-03-29
DE924809C (de) 1955-03-07
NL44760C (fr) 1900-01-01
GB426228A (en) 1935-03-29

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