US1758779A - High-frequency amplifier circuits - Google Patents

High-frequency amplifier circuits Download PDF

Info

Publication number
US1758779A
US1758779A US258558A US25855828A US1758779A US 1758779 A US1758779 A US 1758779A US 258558 A US258558 A US 258558A US 25855828 A US25855828 A US 25855828A US 1758779 A US1758779 A US 1758779A
Authority
US
United States
Prior art keywords
circuit
coupling
tube
frequencies
tunable
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
US258558A
Other languages
English (en)
Inventor
Bradbury Burke
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 US258558A priority Critical patent/US1758779A/en
Priority to GB6977/29A priority patent/GB307295A/en
Application granted granted Critical
Publication of US1758779A publication Critical patent/US1758779A/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 circuits employed for the purpose of amplifying high frequency currents, and particularly currents of the frequencies employed for radio signaling purposes.
  • One of the objects of my invention is to provide an amplifying system which is capable of amplifying efliciently, high frequency voltages over a wide range of frequenci'es such, for example, as the range of frequencies employed'for radio broadcasting.
  • a more specific object of my invention is to provide a circuit arrangement which will be capable of producing a substantially uniform degree of amplification over the complete range of frequencies for which it is intended to be employed.
  • a system for the reception, amplification and detection of radio signals comprising a plurality of vacuumtubes 1 to 5 inclusive, which are supplied with circuit connections whereby radio signals received upon the antenna 6 may be amplified and detected and supplied in suitable intensity to the output terminals 7 of the system.
  • Tubes 1 and 2 are of the type now known as four-element screen-grid tubes.
  • the signals received upon the antenna 6 are impressed upon the control grid 8 of tube 1 this grid being directly connected to the antenna system.
  • the output circuit of tube 1 includes the primary 9 of a coupling trans former, the secondary 10 of which forms a part of a tuned link circuit connecting the output circuit of tube 1 with the input circu-it of tube 2.
  • This transformer may have a one to one ratio and be closely coupled so as to alford an efiicient energy transfer to the linkcircuit.
  • a magnetic coupling is provided between this tuned link circuit and the input circuit of tube 2 by meansof a coupling trans- I former having a primary winding or coupling coil 11 and a secondary winding 12.
  • the link circuit and the input circuit of tube 2 may be tuned in the usual manner by means of variable condensers 13 and 1% operated simultaneously by a single control means.
  • the electromagnetic coupling furnished by the coils 11 and 12 is preferably very loose. I have found, for example, that the primary winding or coil 11 may consist of only one and one-half turns wound close to the secondary winding 12 consisting of sixty-four turns, about two inches in diameter.
  • the two coupling transformers are so arranged that there is no magnetic coupling between them. This may be accomplished by placing them at right angles to each other or by other known methods.
  • the electrostatic coupling should beso arranged that the potential supplied thereby to the input circuit is substantially 180 out of phase with the potential fed through the magnetic coupling.
  • the electrostatic cou pling must be so proportioned that it will never be of greater magnitude than the magnetic couplin If the two were of the same magnitude at a particular frequency no voltage transfer would result and the arrangement would be inoperative at that frequency.
  • the couplings may be adjusted at the highest frequency at which the circuit is intended to operate in such a way as to get maximum sensitivity without too much effective coupling. At lower frequencies the effects of the two couplings will Vary but the effective coupling will. always be the difference between the two, and this may bemade to be substantially constant.
  • the desired electrostatic coupling may be obtained by suitable relation of the various elements of the circuit as above described it may in some cases be desirable to provide electrostatic shielding means between the circuits and provide a desired equivalent electrostatic or condenser coupling of suitable value by other means than that fur ished by the physical relation between the circuits.
  • the magnetic coupling as being made at the low potential ends of the coupling coils. This is preferable because of the fact that it reduces the capacity coupling between the windings, which would otherwise be of too great a magnitude.
  • the output circuit of tube 2 is coupled by means of a coupling transformer 15 to the input circuit of tube 3, which is of the usual three electrode type, and is connected to serve as a detector.
  • the input circuit of this tube is tuned by means of a tuning condenser 16 and the tuning condensers 13, 14 and 16 may all be connected on the same shaft to provide unicontrol.
  • the output circuit of tube 3 includes a tickler coil 17 to provide regenera tion and the resulting increased amplification.
  • This tickler coil 17, instead of being made adjustable, is fined, but is so arranged to give a substantially uniform degree 0' regenerative amplification over the entire operating range of the system. This effect is accomplished by shunting a portion of the coil 17 by a condenser 18 and a resistance 19.-
  • the condenser 18 and the portion of coil 17, which it shunts, are so selected and proportioned that the parallel circuit formed thereby will tend to resonate at a frequency somewhat lower than the lowest frequency of the range over which the circuit is intended to Operate.
  • the fixed tickler arrangement as is well known, is most effective at the higher frequencies and its effectiveness falls off materially at the lower frequencies.
  • the parallel circuit described approaches resonance it increases the amount of feedback provided by the tickler and therefore increases the regenerative amplification at the lower frequencies. If the tuning of this parallel circuit is very sharp, however, this will only be of. benefit over a short range of the lower frequencies to be amplified.
  • the antenna circuit is preferably so proportioned that it is not resonant at any point over the operating range of frequency of the circuit.
  • the voltage on the grid is increased somewhat by reason of the fact that the an tenna tuning which is naturally broad is approaching resonance. This effect of course decreases as the frequency increases.
  • a series condenser 30 is employed of fairly small capacity in order that the apparatus may be used with a wide variety of antennae, and in order that the performance of the set as a whole will not depend greatly upon the capacity of the particular antenna with which it is employed. That is, the capacity 30, being small will in all cases limit the effective capacity of the circuit, although the capacity of the antenna in series with it may vary over quite a wide range.
  • tunable input circuit a coupling coil in said tunable link circuit, said coil being electromagnetically coupled to the tunable input circuit of the second device, said tunable link circuit and said tunable input circuit being arranged to provide an electrostatic coupling between them, the voltage supplied by the electrostatic coupling being of smaller value than and substantially 180 out of phase with the voltage supplied by the electromagnetic coupling, and the two couplings being so proportioned that the difference between the voltages supplied by the two couplings will be substantially uniform throughout the specified range of frequencies.
  • a vacuum tube radio receiving system adapted for operation over a specified range of frequencies, of a fixed antenna system which is not resonant to any frequency within the operating range of the system, said antenna system being arranged and proportioned to impress upon the control grid of a vacuum tube substantially equal voltages for equal signal strengths over the entire operating range of the system, a selective coupling system for transferring voltage to the tuned input circuit of a vacuum tube amplifier, said coupling system including a screen grid vacuum tube having a control grid connected with said antenna system, an output transformer for said tube having a tunable secondary and a coupling coil in series therewith, said coupling system being also arranged to transfer substantially equal voltages for equal signal strengths over the entire operating range of the system, and a regenerative detector having a fixed feed-back coupling system arranged to give substantially uniform amplification over the entire operating range of the system.

Landscapes

  • Magnetically Actuated Valves (AREA)
  • Amplifiers (AREA)
US258558A 1928-03-02 1928-03-02 High-frequency amplifier circuits Expired - Lifetime US1758779A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US258558A US1758779A (en) 1928-03-02 1928-03-02 High-frequency amplifier circuits
GB6977/29A GB307295A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1928-03-02 1929-03-04

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US258558A US1758779A (en) 1928-03-02 1928-03-02 High-frequency amplifier circuits

Publications (1)

Publication Number Publication Date
US1758779A true US1758779A (en) 1930-05-13

Family

ID=22981093

Family Applications (1)

Application Number Title Priority Date Filing Date
US258558A Expired - Lifetime US1758779A (en) 1928-03-02 1928-03-02 High-frequency amplifier circuits

Country Status (2)

Country Link
US (1) US1758779A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)
GB (1) GB307295A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html)

Also Published As

Publication number Publication date
GB307295A (GUID-C5D7CC26-194C-43D0-91A1-9AE8C70A9BFF.html) 1930-06-04

Similar Documents

Publication Publication Date Title
US2140770A (en) Electrical coupling device
US2358520A (en) Coupling transformer
US2543973A (en) Plural-frequency coupling unit
US2246385A (en) Signal collecting system for radio receivers
US1758779A (en) High-frequency amplifier circuits
US1691125A (en) Transformer
US2038294A (en) Coupling system
US2310896A (en) Frequency modulaton receiver
US2619588A (en) Highly selective receiver circuit
US1817294A (en) Electrical coupling system
US1927672A (en) Wave signaling system
US2517741A (en) Permeability-tuned variable-frequency amplifier
US2085444A (en) Radio apparatus
US1933402A (en) Double band receiver
US2219175A (en) Television intermediate frequency separation circuit
US1742602A (en) Selector system
US1614136A (en) Thermionic amplifying apparatus
US1771914A (en) Radio-frequency amplification
US2289594A (en) Coupled loop collector circuit
US2122257A (en) Multirange coupling circuit
US1605411A (en) Nonoscillating radiofrequency selective amplifier
US2264890A (en) Amplifier coupling circuit
US1834408A (en) Electric signaling
US2215774A (en) Combined wired radio and space radio receiving system
US2224115A (en) Band-filter coupling circuit for television amplifiers