US1968105A - Amplifier system - Google Patents

Amplifier system Download PDF

Info

Publication number
US1968105A
US1968105A US488148A US48814830A US1968105A US 1968105 A US1968105 A US 1968105A US 488148 A US488148 A US 488148A US 48814830 A US48814830 A US 48814830A US 1968105 A US1968105 A US 1968105A
Authority
US
United States
Prior art keywords
tube
circuit
input
amplifier
capacity
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
US488148A
Other languages
English (en)
Inventor
Walter Van B Roberts
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
Radio Corporation of America
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 Radio Corporation of America filed Critical Radio Corporation of America
Priority to US488148A priority Critical patent/US1968105A/en
Priority to DER82982D priority patent/DE585341C/de
Application granted granted Critical
Publication of US1968105A publication Critical patent/US1968105A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/02—Details
    • H03J3/06—Arrangements for obtaining constant bandwidth or gain throughout tuning range or ranges

Definitions

  • My present invention relates to electron discharge tube amplifier systems, and more particularly to novel methods of, and means for, amplifying radio frequencies over a relatively wide frequency range in a non-tunable amplifier system employing electron discharge tubes.
  • Another important object of the invention is to provide in a radio receiver'simple means for selecting a desired band of frequencies from a range of frequencies, and a self-tuning amplifier for amplify ing the selected band, said amplifier comprising at least one stage including a four electrode screen grid electron discharge device, and means associated with'at least one electrode for maintaining the stage uniformly resonant throughout said range.
  • Still another object of the invention is to providein a radio broadcast receiver a simple, highly selective, band selector unit, and a'plurality of self-tuning radio frequency amplifier circuits, each circuit'embodying a screen grid tube, and means associated with the screen element for rendering its associated circuit automatically resonant to impressed, selected frequencies.
  • Still other objects of the invention are to improve generallythe compactness and design'of radio frequency amplifiers, and to provide a receiver employing self-tuning amplifier units which'is' reliable in operation, and economical in design and assembly.
  • Fig. 1 shows diagrammatically a radio receiver embodying the invention
  • FIG. 2 is an electrical analysis of the invention
  • Fig. 3 is a circuit showing a modified form of the invention. I a
  • Fig. 1 shows a receiving circuit wherein an antenna A
  • the coil 2 is coupled, as at M, to a second tunable circuit comprising an inductance coil 3 and a shunting variable condenser 6, the condensers 5 and 6 being controlled by a common means '7, shown by dotted lines.
  • the two resonant circuits coupled by the untuned common reactance, the mutual inductance MP of the coils' 2 and 3, represent a band pass my invention may be car-' mon control means 7, the band pass selector unit will impress upon the subsequent amplifier the desired band of frequencies, atpresent 10 kilocycles wide.
  • the subsequent radio frequency amplifier comprises a plurality of self-tuning stages of amplification, of which plurality of stages, I have only shown one in detail for the sake of simplicity of showing, it being clearly understood that the output circuit of the stage to bedescribed is coupled by an inductance coil 10 to' any desired number of succeeding stages of self-tuning radio frequency stages, detector and subsequent audio amplifier stages and loud speaker.
  • a self-tunable radio frequency amplifier stage, ac: cording to this invention comprises an electron discharge tube 9 of the screen grid type, the control electrode of the tube and the cathode being connected to an inductance coil 4.
  • the coil i is coupled to the inductance coil 3 of the band pass selector unit.
  • the screen element 11 of the tube has impressed thereon the desired positive potential, about 45 volts in present practice, while the anode of the tube is supplied with energy from a source B through an inductance coil 12, which inductance coil is coupled to the coil 10.
  • This automatic means comprises an auxiliary electron discharge tube 8, shown as of the triode type, the input electrodes, the control electrode and the cathode, being connected across the inductance coil 4.
  • the anode of; the tube 8 is energized from a source B through an impedance conventionally represented by the symbol Z.
  • Z an impedance conventionally represented by the symbol Z.
  • Fig. 2 there is shown an electrical and graphical analysis of the action of the tube 8, and its associateed capacities C, K and impedance Z.
  • the symbolic representation Z1 includes the input capacity of the'amplifienthe eifect of the plate circuit of the preceding amplifier and the capacity C of the tube 8.
  • Z4 is an impedance of predetermined character located in the plate circuit of tube 8, and
  • Z3 is likewise the impedance of an arbitrarily chosen network connecting plate and grid of tube 8, although frequently this network may be chosen to consist merely of the natural grid and plate capacity of the tube as shown atK of Fig. 1.
  • the minimum total value of apparent capacity may be calculated by summing up the capacity between the grid and cathode of tubes 8 and 9, and between grid and screen of the tube 9; and the equivalent capacity across the secondary due to the capacity across the primary, thus making. a .total of about 35 cms., plus coil capacity, plus the apparent capacity produced by Z3 and Z4.
  • the maximum value is equal to the minimum value times the square of the wave length range desired (expressed as a ratio). Therefore, the network Z must be suitably determined to cause this variation in total apparent capacity.
  • the operation of the self -tunable circuit is as follows: the lower the frequency of signals impressed, the greater the apparent total capacity across coil 4, thus, whatever the signal frequency, the apparent capacity across coil 4. is of approximately the correct value to-Ftune coil to the signal being received.
  • the simplest structure for Z of Fig. l' is a variable resistance, uni-controlled with the signal selector so that its value runs from zero at the highest frequency setting of the selector, to a value sufficiently large to tune in the lowest frequencies at the lowest frequency setting of the selector.
  • networks of fixed constants having approximately the same resistance characteristic are preferred where possible, to avoid the necessityfor adjustment. 1
  • FIG. 3 A modified form of the invention is shown in Fig. 3, the screen element 11 being employed to perform the function of the auxiliary tube 8 in Fig. 1. This is accomplished by inserting in the screen circuit an impedance Z for the purpose of determining in a desired fashion the variation of apparent input capacity of the tube.
  • Means for selecting and amplifying high frequency oscillations comprising. a tunable band pass selector unit, and an untuned screen grid tube amplifier having means in its input circuit for automatically maintaining resonancev insaid amplifier input over a frequency range in accordance with tuning of said unit.
  • Means for selecting and amplifying high frequency oscillations comprising a tunable band pass selector unit, and an untuned screen grid tube amplifier having an auxiliary tube in its input circuit for maintaining resonance in said amplifier input over a frequency range in accordance with tuning of said unit.
  • an amplifier tube having a normally untuned inductive input circuit, and a tube having its input electrodes connected across the amplifier input providing sumcient capacity to uniformly tune the inductive circuit to desired frequencies throughout a frequency range.
  • an amplifier tube having a normally untuned inductive input circuit, and a tube having its input electrodes connected across the amplifier input providing sufficient capacity to uniformly tune the inductive circuit to desired frequencies throughout a frequency range, said second tube having a predetermined amount of impedance in its output circuit.
  • an amplifier tube having a normally untuned inductive input circuit, and a tube having its input electrodes connected across the amplifier input providing sufficientcapacity to uniformly tune the inductive circuit to desired frequencies throughout'a frequency range and an adjustable frequency selector preceding said inductive circuit.
  • a resonant circuit including a coil and a tube having its input electrodes connected across said coil, means for selecting signal frequencies of a desired frequency range to be impressed on said. coil, a second tube connected to said coil, and an impedance in one of the cold electrode circuits of said second tube of a magnitude such that the input capacity of said first tube is caused to vary with impressed selected frequencies to tune the circuit to such frequencies.
  • a resonant circuit including a coil and a tube having its input electrodes connected across said coil, means for selecting signal frequencies of a desired frequency range to be impressed on said coil, and a resistor in the anode circuit of said tube of a magnitude such that the input capacity of said tube is caused to vary with impressed selected frequencies to tune the circuit to such frequencies.
  • a resonant circuit including a coil and a tube having its input electrodes connected across said coil, means for selecting signal frequencies of a desired frequency range to be impressed on said coil, and a resistor in one of the cold electrode circuits of said tube

Landscapes

  • Amplifiers (AREA)
US488148A 1930-10-11 1930-10-11 Amplifier system Expired - Lifetime US1968105A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US488148A US1968105A (en) 1930-10-11 1930-10-11 Amplifier system
DER82982D DE585341C (de) 1930-10-11 1931-10-08 Radioempfangsschaltung

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US488148A US1968105A (en) 1930-10-11 1930-10-11 Amplifier system

Publications (1)

Publication Number Publication Date
US1968105A true US1968105A (en) 1934-07-31

Family

ID=23938506

Family Applications (1)

Application Number Title Priority Date Filing Date
US488148A Expired - Lifetime US1968105A (en) 1930-10-11 1930-10-11 Amplifier system

Country Status (2)

Country Link
US (1) US1968105A (de)
DE (1) DE585341C (de)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR805703A (fr) * 1935-05-03 1936-11-27 Rca Corp Système de contrôle automatique de la fréquence pour récepteur superhétérodyne

Also Published As

Publication number Publication date
DE585341C (de) 1933-10-02

Similar Documents

Publication Publication Date Title
US2323598A (en) Variable signal response network
US2024489A (en) Circuit arrangement for generating or amplifying electric oscillations
US2038879A (en) Reduction of interference in thermionic valve circuits
US1938620A (en) Band-pass amplifier
US1968105A (en) Amplifier system
US2051898A (en) Receiver selectivity and amplification control
US2033986A (en) Frequency converter
US2256067A (en) Receiver selectivity control
US2140339A (en) Frequency control circuits
US2075526A (en) Radio signal receiving system
US2041150A (en) Automatic gain control
US2124211A (en) Combined amplification and tuning controls
US2017270A (en) Electronic tone control
US1981071A (en) Amplifier circuits
US2219396A (en) Electric translating system
US2201365A (en) Duplex vacuum-tube repeater
US1969903A (en) Superheterodyne receiver
US2155467A (en) High frequency amplifier
US2231367A (en) Automatic frequency control circuit
US2054637A (en) Superheterodyne receiver
US1962392A (en) Electric tube frequency multiplier
US1890426A (en) Radio receiving system
US2017131A (en) Intermediate frequency amplifier
US2006526A (en) Tuning circuit
US2055996A (en) Band-pass amplifier