US1874891A - Keying circuit arrangement for transmitters - Google Patents

Keying circuit arrangement for transmitters Download PDF

Info

Publication number
US1874891A
US1874891A US388108A US38810829A US1874891A US 1874891 A US1874891 A US 1874891A US 388108 A US388108 A US 388108A US 38810829 A US38810829 A US 38810829A US 1874891 A US1874891 A US 1874891A
Authority
US
United States
Prior art keywords
keying
tube
grid
transmitters
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
US388108A
Other languages
English (en)
Inventor
Buschbeck Werner
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.)
Telefunken AG
Original Assignee
Telefunken AG
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 Telefunken AG filed Critical Telefunken AG
Application granted granted Critical
Publication of US1874891A publication Critical patent/US1874891A/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
    • H04L27/02—Amplitude-modulated carrier systems, e.g. using on-off keying; Single sideband or vestigial sideband modulation
    • H04L27/04—Modulator circuits; Transmitter circuits

Definitions

  • WERNER BUSCHBECK OF BERLIN, GERMANY, ASSIGNOR 'ro EEEETINK N i SCHAF'I' FUR DRAHTLOSE' TELEGRAPHIE'M. B. 11, or EEREINJGERMANX, ,AeooRPe I, RATION or GER-MANY I KEYING CIRCUIT ARRANGEMENT EoR "rRANsMIrTE s I Application filed August 24, 1929, Serial Nd. 388,108, and "i Germany June [30, 192 s.
  • the keying arrangement heretofore used in connection with transmitter tubes is of a kind in which the tubes were connected for grid modulation.
  • the grid of these tubes was rendered so markedly negative by means of a potential applied through a high resistance that the tube would be blocked.
  • the key was disposed between the grid and the filament of the modulator tube.
  • the relay in the first place, had the full grid direct current potential to ground (crest value of grid alternating current potential of the pilot tube, or even more when a biasing potential was employed).
  • the internal resistance of the modulator tubes, when grid and filament are united, is rather high, so that, to insure the desired direct current grid resistance, it was mostly necessary to provide a larger number of paralleled tubes.
  • the primary object of, this invention is to provide a novel keying system which will overcome the above defects.
  • the circuit arrangement herein disclosed involves a transmitter relay tube H which has a high frequency input circuit 1 on which oscillations to be modulated are impressed.
  • Keying or modulating of the high frequency oscillations is accomplished through a keying tube M in the direct current input circuit of H as shown.
  • the arrangement of the present invention difiers from the of the modulator or keying tube Mas shown rather than between the grid and the fila- I .ment of the said tube.
  • the key-T may be either direct between the plate tand grid 30f M or else through a resistancelt as shown.
  • the keying tube Mis'blocked. .VVhen Tfis closed, the grid 3 of. M assumes a positive biasing potential with relation to its filament '5.”
  • the value of said biasing potentiahis governed by the value of the resistance. R, connectedin, series-with the key.
  • je grid 3 may have a. maximum value r 5 equalling that of the plate potentiah Under this condition, the tubena-turally has a far lower internal resistance, and as a consequencaa smaller number of keying tubes M Will su fiice.” .Anotheradvantage 7 of the present arrangement is that the keying relay is grounded as shown. :This feature is desirable in case" of re-adjustment of the circuit elements ,during operation.
  • the same keying circuit is suitable also for indicating modulated continuous wave trans- 8'5 mission.
  • This is accomplished by the use of an oscillating modulator or'keying tube M of Figure 2.
  • the grid direct current resistance R of the oscillating modulator or keying tube is con- '90 nected at the plate 4 of the modulator tube instead of at the filament according to former practice.
  • the said resistance R must be chosen so high that the grid di- I rect current flowing through it willcompensate the plate potential. Oscillation of tube M and the associated circuits is insured by the coupling between the tuned plate circuit 10 and the inductance 11 in the grid circuit when the key T is closed.
  • Closing of the key T decreases the negative potential on the grid 3 of the tube M and renders said tube more conductive. This results in a large amount of rectified direct current flowing in the grid circuit of the tube H to pass between the cathode and plate of tube M. This direct current flowing in this circuit raises the positive potential on the plate. This positive potential is transmitted through the closed key T and resistance R to the grid of the tube M to overcome the negative potential applied thereto from the battery 16.
  • biasing potential for the grid electrode 8 of tube M is supplied from a source 15 through a resistance 15.
  • the high frequency oscillations relayed in H are shunted around the keying circuits by a condenser C aIn Figure 2 the keying oscillations produced in M are passed around the battery 16 and resistance 15 by a condenser G I I claim: 1.
  • a modulating means for an oscillation amplifier including, a thermionic tube having input and output elements, means for imodulating the oscillations repeated in said amplifier including, a thermionic keying tube having anode cathode and grid electrodes,
  • the circuit connected in parallel with the input elements of said keying tube includes an inductance and in which the keying circuit includes an inductance coupled to said first named inductance.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Transmitters (AREA)
US388108A 1928-06-30 1929-08-24 Keying circuit arrangement for transmitters Expired - Lifetime US1874891A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE314535X 1928-06-30

Publications (1)

Publication Number Publication Date
US1874891A true US1874891A (en) 1932-08-30

Family

ID=6146456

Family Applications (1)

Application Number Title Priority Date Filing Date
US388108A Expired - Lifetime US1874891A (en) 1928-06-30 1929-08-24 Keying circuit arrangement for transmitters

Country Status (4)

Country Link
US (1) US1874891A (zh)
BE (1) BE361597A (zh)
GB (1) GB314535A (zh)
NL (1) NL27128C (zh)

Also Published As

Publication number Publication date
BE361597A (zh)
GB314535A (en) 1930-07-17
NL27128C (zh)

Similar Documents

Publication Publication Date Title
US2282714A (en) Method and means for the linear transmission or amplification of amplitude-modulatedcarrier waves
US1874891A (en) Keying circuit arrangement for transmitters
GB367978A (en) Improvements in or relating to methods and means for generating electrical oscillations
GB406674A (en) Improvements in or relating to modulated carrier wave transmitting systems
US2346800A (en) Wave length modulator
US2247442A (en) Neutralizing arrangement for amplifiers
US2393936A (en) Prevention of distortion
US2136479A (en) Modulation system
US1687882A (en) Oscillation generator and modulator
US2013807A (en) Modulation
US2114336A (en) Modulated wave transmitter
US2095327A (en) Phase modulation
US1967253A (en) Modulated high frequency generator
US1828852A (en) Tube transmitter keying method
GB411644A (en) Improvements in or relating to modulated carrier wave transmitters
US1795858A (en) Radio transmission system
GB262076A (en) Improvements in or relating to modulation systems applicable to wireless signalling
US2225691A (en) Frequency modulation
US1830175A (en) Thermionic tube circuit
US1949248A (en) Keying system
US2051493A (en) Modulated carrier wave transmitter
GB424470A (en) Improvements in or relating to modulating and keying systems for radio and like transmitters
US1494908A (en) Amplification of modulated waves
US2198431A (en) Modulated carrier wave transmitter
US1936162A (en) Transmission system