US2279930A - Electronic modulator for constant frequency variable dot transmission - Google Patents

Electronic modulator for constant frequency variable dot transmission Download PDF

Info

Publication number
US2279930A
US2279930A US287019A US28701939A US2279930A US 2279930 A US2279930 A US 2279930A US 287019 A US287019 A US 287019A US 28701939 A US28701939 A US 28701939A US 2279930 A US2279930 A US 2279930A
Authority
US
United States
Prior art keywords
anode
electron
target
modulation
wave
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
US287019A
Other languages
English (en)
Inventor
Shelby Robert Evart
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.)
RCA Corp
Original Assignee
RCA Corp
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
Priority to FR825785D priority Critical patent/FR825785A/fr
Priority to CH204655D priority patent/CH204655A/de
Application filed by RCA Corp filed Critical RCA Corp
Priority to US287019A priority patent/US2279930A/en
Application granted granted Critical
Publication of US2279930A publication Critical patent/US2279930A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K7/00—Modulating pulses with a continuously-variable modulating signal
    • H03K7/08—Duration or width modulation ; Duty cycle modulation

Definitions

  • Patented Apr. 14, 1942 TENT OFFICE ELECTRONIC MODULATOR FOR CONSTANT FREQUENCY VARIABLE nor TRANSMIS- SION Robert Evart Shelby, Teaneck, N.
  • Figures 1 and la illustrate one form which the plate or target anode may take and the relation of the same to the other'electrodes of an electron discharge gun or cathode ray tube used to produce CFVD modulation in accordance with my invention
  • Figure 2 shows schematically the essential elements of my novel circuit for producing and applying potentials to the deflecting plates of an electron gun as illustrated in the prior figures and the mode of connecting the output of the novel circuit to the pairs of deflecting plates in an electron tube having a novel plate or target anode arranged in accordance with the present invention
  • Figure 2a illustrate a phase shifter used in the circuit of Figure 2
  • Figures 3a, 3b, 3c and 4 are curves illustrating the character of the output of an electron gun with an anode as indicated in Figures 1 and 111 when the deflecting plates are excited :as indicated in Figure 2;
  • Figure 5 shows a modified anode structure
  • Figure 6 is a curve representing the output of a system when the anode is as shown in Figure 5.
  • Figures '7, 7a, 8, 8a, 9 and 9a illustrate modified forms of final or target anodes.
  • the tube illustrated diagrammatically in Figures 1 and 1a consists essentially of an electron tube 4, two sets of electrostatic deflecting plates 6 and 8, and a final anode Ill.
  • the target anode I0 is of special design.
  • Figure 1a shows one form which the final anode 10 may have for production of CFVD modulation.
  • the final anode or target 10 consists of two curved plates l4 and I6, having the complementary boundaries indicated by Figure 1, upon which the electrons from the electron gun impinge.
  • the electrodes l4 and I6 may consist of metallic plates or meshes or metallic deposits on the tube envelope or a surface supported in said tube. Where the electrodes l4 and I6 are of mesh 2.
  • collecting electrode not shown, may be located back of the targets and properly charged relative to the other electrodes.
  • the am- 1 plitude modulated radio frequency or carrier jes the angular-displacement of the same point' from a selected datum line which is the same for each curve; while a and 6 are design constants, the latter depending on the spacing of the anode sections.
  • the electron gun is controlled and "quency waves are applied to input terminals and from said input terminals to a resistance in series with condenser 32.
  • the condenser 32 By adjusting the condenser 32 and selecting the value of 30, the desired phase relation between 61 and c2 can be produced.
  • may be modulated in amplitude by facsimile signals, by keyed impulses, by voice frequencies, television or any other type. of signals to produce constant frequency' variable dot characters.
  • voltages of substantiallyconstant frequency and of sinusoidal ,form are supplied from any source to a'modulator of any known type.
  • the oscillations' may be producedby an oscillator of the crystal or line controlled type or of anyother type, the only requirement being that they be of substantially constant frequency and constant alternating current amplitude;
  • may be of any type havingthe desired characteristics. form supplied to 2
  • is connected to an amplitude regulating potentiometer P1 which is connected by a movable point to a phase shifting network 23.
  • This network may take any suitable. form, the essential feature being that the output thereof supplies twoportionsof theamplitude modulated wave in phase displaced relation. The amplitudes of the portions are substantially equal.
  • the output voltage will be as shown in Figure 311; It will benotedthat the electron stream passes from one segment, say I 4, of the'target anode to the other, say segment l6, and from thelatterto the former at points P1 and P1',"whichare 180 apart. This means that the positive and'negative portions of each cycle of the flat-topped supersonic output voltage wave are equal, and this adjustment therefore corresponds to. zero modulation. If now the two deflecting voltages from 23v are decreased. in amplitude to almost zero by changing potentiometer P1, all other controls being left the same, the locusof the end-point of the electron stream will be 02 of Figure 1a, and the voltage acrossZA will'be as shown in Figure 3b.
  • the electronstreamncw passes from one segment, say M, of the anode to the other, say segment l6, and from the latter tothe former at points P: and P2. Likewise; if the potentiometer P1 is adjusted to'give' voltages, almost double those which produced the locus cithen 03 will be the new locus, the electronstream will pass from one anode segment to the other at points pa and pa and the voltage appearing across ZA will be as shown in Figure 30.
  • This device may be used'to convert potentials of any frequency of sine wave form intovoltages of flattopped wave form of equal'frequency the duration of the dots of which can be adjusted through a wide range. This ismaccoinplished by applying an unmodulated wave of sine wave form to P1 and adjusting the same to make 61 and ez of the desired value.
  • the flat topped wave .so produced is of wide application in .the
  • radio and allied arts are of particular value for television pictures and synchronization.
  • Figure 4 shows what a CFVD modulated flat topped supersonic wave looks like.
  • the modulation is a sine wave the frequency of which is /2 that of the supersonic wave, and the percent of CFVD modulation is 75..
  • this CFVD modulated voltage wave may be used to amplitude modulate or key a radio frequency carrier wave which may be used for signalling in any known system.
  • a complete modulating system arranged in accordance with my invention has been shown in Figure and will now be described.
  • Figure 5 illustrates one form of final or target anode for the electronic modulator or electron gun modulator which will give the modified CFVD modulation outlined above. It is practically the same as the one shown in Figures 1 and 1a except that a third target anode segment H5 has been added between the segments l4 and It.
  • the electrode H5 is electrically independent of the other two segments and is connected to the high voltage direct current supply source through an additional coupling impedance Zn, across which the output appears comprising short sharp impulses.
  • the wave of Figure '7 is used to amplitude modulate or, optionally, to key the radio frequency carrier.
  • the modulated wave in Figure '7 may be applied to the grid electrode of a radio frequency amplifier to control its bias and key the tube.
  • the target of Figures 8 and 8a is particularly adapted to production of CFVD as is the anode or target electrode of Figure la. :In this arrangement, electrode It may also ;be utilized as the collecting electrode to supplement or replace the action of electrode 9!! of Figure ;5 of my original application.
  • the target 11-5 may be placed in front of a plate H ⁇ as shown in Figures 9 and 9a.
  • the electrodes M and it. and Q and J5 and H5 may be coatings or deposits on the tube envelope properly separated by insulating material or supported thereby.
  • An electron discharge device having a target comprising a plurality of superimposed surface bearing members arranged about a focal point, one of which surface bearing members is substantially of a shape defined by the intersection of two Archimedes spirals.
  • An electron discharge device having a target comprising two or more surface bearing members arranged about a focal point, one of said surface bearing members being substantially of a shape defined by the intersection of two Archimedes spirals and lying within the area of the other surface bearing member from which it is conductively separated.
  • An electron discharge device having a target comprising two or more surface bearing members arranged about a focal point, one of said surface bearing members being substantially of a shape defined by the intersection of two Archimedes spirals and lying within the projected area of the other surface bearing member.
  • An electron discharge device having a target comprising three surface bearing members arranged about a focal point, two of which surface bearing members are substantially of a shape defined by the intersection of two Archimedes spirals and disposed wholly within the area of the remaining surface bearing member, all of said surface bearing members being conductively separated.
  • An electron discharge device having a target comprising three plates arranged about a focal point, two of which plates are substantially of a shape defined by the intersection oi! two Archimedes spirals and disposed wholly within the projected area'of the remaining plate.
  • An electron discharge device having a target anode comprising a plurality of conducting elements arranged in a saucer-shaped surface about a focal point, at least one of said plates being substantially of a shape defined by the intersection of two Archimedes spirals.
  • an electron emission element an electron emission element, a-pair of anode electrodes, one of which is substantially of a shape defined by the intersection of two Archimedes spirals, in the path of emission from said emission element, and pairs of similar deflecting electrodes adjacent the path of said emission.
  • an electron emission element in an electron discharge device, an electron emission element, three anode electrodes, two of which are substantially of a shape defined by the intersection of two Archimedes spirals and located wholly within the area oi. the third electrode, and pairs of similar deflecting electrodes adjacent the path of said emission.
  • an electron emission element a pairof anode electrodes, one of which is substantially of a shape defined by the intersection of two Archimedes spirals, both of which are in the path of emission from said element, pairs of deflecting electrodes adjacent the path of said emission and a collecting anode adjacent said anode electrodes.
  • an emission element In an electron discharge device, an emission element, a pair of anode electrodes spaced therefrom and a plurality of anode electrodes in the path of emission from said element, one of said electrodes having an opening substantially of a shape definedby the intersection of two Archimedes spirals opening therein and being disposed between another of said anode electrodes and said emission element.

Landscapes

  • Particle Accelerators (AREA)
US287019A 1936-09-14 1939-07-28 Electronic modulator for constant frequency variable dot transmission Expired - Lifetime US2279930A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
FR825785D FR825785A (fr) 1936-09-14 1937-08-20 Modulateur électronique pour la transmission à modulation à fréquence constante et à éléments variables
CH204655D CH204655A (de) 1936-09-14 1937-09-13 Schaltungsanordnung mit einer Kathodenstrahlröhre.
US287019A US2279930A (en) 1936-09-14 1939-07-28 Electronic modulator for constant frequency variable dot transmission

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10062736A 1936-09-14 1936-09-14
US287019A US2279930A (en) 1936-09-14 1939-07-28 Electronic modulator for constant frequency variable dot transmission

Publications (1)

Publication Number Publication Date
US2279930A true US2279930A (en) 1942-04-14

Family

ID=26797379

Family Applications (1)

Application Number Title Priority Date Filing Date
US287019A Expired - Lifetime US2279930A (en) 1936-09-14 1939-07-28 Electronic modulator for constant frequency variable dot transmission

Country Status (3)

Country Link
US (1) US2279930A (fr)
CH (1) CH204655A (fr)
FR (1) FR825785A (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2452646A (en) * 1944-05-29 1948-11-02 Frankel Leo Lamp housing for film projectors
US2545123A (en) * 1946-05-20 1951-03-13 Rca Corp Computing device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2452646A (en) * 1944-05-29 1948-11-02 Frankel Leo Lamp housing for film projectors
US2545123A (en) * 1946-05-20 1951-03-13 Rca Corp Computing device

Also Published As

Publication number Publication date
FR825785A (fr) 1938-03-14
CH204655A (de) 1939-05-15

Similar Documents

Publication Publication Date Title
US2265337A (en) Pulse generating and pulse modulating system
US2257795A (en) Electron discharge apparatus and circuits
US2144337A (en) Electrical device
US2171150A (en) Electronic modulator fob constant
US2165028A (en) Television and the like system employing cathode ray tubes
US1920863A (en) Amplification of radiant energy
US2201323A (en) Electronic modulator and method of modulation
US2262406A (en) Frequency modulation system
US2069441A (en) Electron tube
US2589460A (en) Electronic commutator
US2199066A (en) Electro-optical method and apparatus
US2279930A (en) Electronic modulator for constant frequency variable dot transmission
US2638561A (en) Cathode-ray oscillator tube
US2072658A (en) Receiver arrangement for electric picture transmission
US2123011A (en) Electron discharge apparatus
US2413276A (en) Cathode-ray apparatus
US2548405A (en) Electron tube
US2612634A (en) Angular modulation
US2225330A (en) Electron beam tube
US2801363A (en) Dynamic electron beam control systems
US2307035A (en) Electron multiplier
US2313886A (en) Electronic valve device
US2507170A (en) Timing modulation
US2822493A (en) Graphechon storage tube
GB548735A (en) Apparatus for electron discharge control