US2147554A - Television receiver - Google Patents

Television receiver Download PDF

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Publication number
US2147554A
US2147554A US46125A US4612535A US2147554A US 2147554 A US2147554 A US 2147554A US 46125 A US46125 A US 46125A US 4612535 A US4612535 A US 4612535A US 2147554 A US2147554 A US 2147554A
Authority
US
United States
Prior art keywords
aerial
circuit
grid
stage
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
US46125A
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English (en)
Inventor
Schlesinger Kurt
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.)
Loewe Opta GmbH
Original Assignee
Loewe Opta GmbH
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 claimed from US2631A external-priority patent/US2173495A/en
Priority to FR786900D priority Critical patent/FR786900A/fr
Priority to FR786335D priority patent/FR786335A/fr
Application filed by Loewe Opta GmbH filed Critical Loewe Opta GmbH
Priority to US46125A priority patent/US2147554A/en
Priority claimed from US46124A external-priority patent/US2226999A/en
Application granted granted Critical
Publication of US2147554A publication Critical patent/US2147554A/en
Priority to US288974A priority patent/US2248561A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
    • H04N5/4446—IF amplifier circuits specially adapted for B&W TV
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/42—Modifications of amplifiers to extend the bandwidth
    • H03F1/48—Modifications of amplifiers to extend the bandwidth of aperiodic amplifiers
    • H03F1/50—Modifications of amplifiers to extend the bandwidth of aperiodic amplifiers with tubes only
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B15/00—Suppression or limitation of noise or interference
    • H04B15/02—Reducing interference from electric apparatus by means located at or near the interfering apparatus
    • H04B15/04—Reducing interference from electric apparatus by means located at or near the interfering apparatus the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder
    • H04B15/06—Reducing interference from electric apparatus by means located at or near the interfering apparatus the interference being caused by substantially sinusoidal oscillations, e.g. in a receiver or in a tape-recorder by local oscillators of receivers

Definitions

  • This invention relatesto a radio receiving system of the heterodyne type and more particularly to a resonant input circuit coupled to the first detector stage having means to prevent the radiation of locally generated oscillations during reception of ultra-short waves.
  • the invention is directed to a new aerial connection arrangement for coupling a special aerial system with a heterodyne receiver using a valve which at the same time serves as a detector, oscillator and mixer, the oscillatory circuit of which is connected to anode and grid, whereby a capaci- 3-5 tive feed-back is effected only by the natural gridanode and grid-cathode capacities.
  • a valve which at the same time serves as a detector, oscillator and mixer, the oscillatory circuit of which is connected to anode and grid, whereby a capaci- 3-5 tive feed-back is effected only by the natural gridanode and grid-cathode capacities.
  • Fig. 1a shows an aerial resonating at a quarter wave length which may be connected to the input 25 terminal 9 instead of the aerial circuit 38 shown in Fig. 1. a
  • the aerial In other cases of reception which are important in practice it is necessary to select the point of erection of the aerial in spatial disposal amounting to a few wave-lengths from the point of erection of the receiving apparatus; for example, the aerial must be located on the roof of a building and the television receiver on the ground floor.
  • Fig. 1 there is provided an aerial resonating at a half wave-length.
  • This aerial 3 in a manner known per se is connected in such fashion with an energy line 4 that at two points 5 and 6 disposed symmetrically to the potential anode of the aerial 3 the two poles of the energy line 4 are tapped and spaced in such fashion in relation to each other that the apparent resistance of the dipole existing between the same is equal to the wave resistance of the line 4, i. e., approximately 500 ohms.
  • the wave resistance of the line 4 i. e., approximately 500 ohms.
  • ultra-short wave may be transmittedover distances of the order of 20 metres and more without appreciable loss.
  • the coupling of the energy line at the receiver end may be performed by means of a step-up transformer with coils I and 8. These coils are preferably coupled very loosely with each other, and the coil 8 is adjusted with the inherent capacities, which arise from the aerial connection 9 to approximate resonance with the received wave. By reason of the loose coupling between I and 8 innumerable high damping effects areavoided, with consequent weakening of the resonance eiiect at 8 due to attenuation by the low-ohmic energy line 4 and the circuit of the coil 8. In practice, for example, the coil 1 possesses approximately 5 turns of mm.
  • the occurrence of interfering oscillations external to the oscillator is avoided by the difierential condenser I4, I5.
  • the oscillatory circuit ll, l2 oscillates when the anode feed line I3 is not, as shown, tapped at the centre of the coil II, but is applied to the end thereof.
  • the middle tapping as shown, however, as already known, provides a maximum oscillation amplitude.
  • the differential condenser I4 [5 a point is found which is neutral against earth potentials of any kind at the heterodyne frequency. This adjustment is performed in the first instance by the makers so that the aerial connection point 9 is then completely decoupled from the heterodyne oscillation of the tube I0, and radiation is avoided.
  • the reception is passed through the medium of a parallel connection of the part capacities [4, I5 of the differential in phase to grid and anode of the tube I0, whereby no potential of the received frequency is produced at the terminals of the circuit I I, 12.
  • the simultaneous connection in phase to grid and anode causes a weakening of the anode current amplified by the grid.
  • the use of screening grid tubes, which overcome the anode reaction, results in a valuable improvement as compared with the use of single-grid tubes as oscillators [0.
  • the point 9 therefore, viewed from the aerial, possesses against earth the nature of a capacity, the resulting amount of which is defined by the series connection of the parallel capacity of [4, l5 and the inherent capacities of the tubes and their circuits.
  • a relatively small differential condenser 15 of approximately cm. part ca pacity, is used so that there is maintained a relatively large wave range in respect of the cir-' cuit l I, I2 with a decrease of detrimental longwave coupling, and also a favourable L/C' ratio for external resonance transformers 8.
  • high-pass filters for example in respect of those frequencies which fall within the order of magnitude of the relatively long intermediate frequency wave of the receiver (approximately 150-200 metres) employed, there are employed high-pass filters in the form 16, I1, which allow the passage of merely the ultra-short waves (for example capacity of 16-100 cm., and a coil of 17-30 windings, turns with 10 mm. diameter).
  • the long-wave absorption is additionally assisted by short circuiting the grid circuit of the tube I0 in respect of long waves by an ultra-short wave choke l8,'which is situated behind a small grid condenser 19 (50 cm.).
  • the two-section high-pass filter as described may also be applied in the aerial circuit or in the lead to the grid or the alternatively ultra-short wave resonance circuits may be connected in the manner of the transformer 1, 8.
  • a negative bias of the control grid is important. This is effected in the most simple fashion by utilising the grid current at a grid resistance 20. In this manner there is also obtained simultaneously a constancy of the oscillation amplitude by self-regulation.
  • the circuit elements 22, 23, and 25-21 in the anode circuit of the valve ID are used for transmitting the intermediate frequency carrier with the corresponding side-bands intermediate frequency to the succeeding amplifier stages.
  • 24 is a resistance in the anode supply line.
  • an aerial circuit a first stage used as local oscillator, amplifier and first detector stage, means ,for coupling said aerial circuit to said first stage, means for preventing radiation of oscillations of said local oscillator, said aerial circuit consisting of a resonance aerial, the length of which being one quarter or a multiple of one quarter of the received Wave-length, and being coupled to said first stage by means of a high-frequency transformer having a primary and a secondary, said primary being disecondary coils being arranged as to form a mechanically unvariable structure which is connected with the aerial circuit.
  • an aerial circuit a first stage used as local oscillator, amplifier and first detector stage, means for coupling said aerial circuit to said first stage, means for preventing radiation of oscillations of said local oscillator, said aerial circuit consisting of a resonance aerial, the length of which being one quarter or a multiple of one quartw of the received wave-length, and being coupled to said first stage by means of a high-frequency transformer having a primary and a secondary, said primary being directly connected to said aerial, said secondary being connected to the grid and oscillatory circuit of said first stage by means of a differential condenser, said primary and secondary being coupled very loosely with each other and said secondary being dimensioned in combination with its inherent capacities to approximate resonance with the received wave, said differential condenser consisting of a rotary electrode and two fixed electrodes, said rotary electrode being connected to the input terminal which is connected through a high-pass filter to one terminal of the secondary the other one of which is earthed, said fixed electrodes being
  • an aerial circuit a first stage used as local oscillator, amplifier and first detector stage, means for coupling said aerial circuit to said first stage, means for preventing radiation of oscillations of said local oscillator, said aerial circuit consisting of a resonance aerial, the length of which being one quarter or a multiple of one quarter of the received wave-length, and being coupled to said first stage by means of a high-frequency transformer having a primary and a secondary, said primary being directly connected to said aerial, said secondary being connected to' the grid and oscillatory circuit of said first stage by means of a differential condenser, said primary and secondary being coupled very loosely with each other and said secondary being dimensioned in combination with its inherent capacities to approximate resonance with the received wave, said differential condenser consisting of a rotary electrode and two fixed electrodes, said rotary electrode being connected to the input terminal which is connected through a high-pass filter to one terminal of the secondary the other one of which is earthed, said fixed electrodes being connected
  • an aerial circuit a first stage consisting of a valve having an anode, a cathode, a control grid and a screening grid used as local oscillator, amplifier and first detector stage, means for coupling said aerial circuit to said first stage, means for preventing radiation of oscillations of said local oscillator, said aerial circuit consisting of a resonance aerial, the length of which being one quarter or a multiple of one quarter of the received wave-length, and being coupled to said first stage by means of a highfrequency transformer having a primary and a secondary, said primary being directly connected to said aerial, said secondary being connected to the grid and oscillatory circuit of said first stage by means of a difierential condenser, said primary and secondary being coupled very loosely with each other and said secondary being dimensioned in combination with its inherent capacities to approximate resonance with the received wave, said primary and said secondary coils being arranged as to form a mechanically unvariable structure which is connected with the aerial circuit.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Multimedia (AREA)
  • Power Engineering (AREA)
  • Superheterodyne Receivers (AREA)
  • Amplifiers (AREA)
US46125A 1934-01-25 1935-10-22 Television receiver Expired - Lifetime US2147554A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
FR786900D FR786900A (fr) 1934-01-25 1935-01-24 Réception de télévision
FR786335D FR786335A (fr) 1934-01-25 1935-01-24 Récepteur de télévision
US46125A US2147554A (en) 1934-01-25 1935-10-22 Television receiver
US288974A US2248561A (en) 1934-01-25 1939-08-08 Intermediate frequency amplifier for television purposes

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
DE452715X 1934-01-25
DE2226994X 1934-04-28
US2631A US2173495A (en) 1934-01-25 1935-01-21 Television receiver
US46125A US2147554A (en) 1934-01-25 1935-10-22 Television receiver
US46124A US2226999A (en) 1934-01-25 1935-10-22 Television receiver
US288974A US2248561A (en) 1934-01-25 1939-08-08 Intermediate frequency amplifier for television purposes

Publications (1)

Publication Number Publication Date
US2147554A true US2147554A (en) 1939-02-14

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ID=32074796

Family Applications (2)

Application Number Title Priority Date Filing Date
US46125A Expired - Lifetime US2147554A (en) 1934-01-25 1935-10-22 Television receiver
US288974A Expired - Lifetime US2248561A (en) 1934-01-25 1939-08-08 Intermediate frequency amplifier for television purposes

Family Applications After (1)

Application Number Title Priority Date Filing Date
US288974A Expired - Lifetime US2248561A (en) 1934-01-25 1939-08-08 Intermediate frequency amplifier for television purposes

Country Status (2)

Country Link
US (2) US2147554A (fr)
FR (2) FR786335A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2823305A (en) * 1955-03-10 1958-02-11 Philips Corp Non-radiating frequency converter for a radio receiver

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2823305A (en) * 1955-03-10 1958-02-11 Philips Corp Non-radiating frequency converter for a radio receiver

Also Published As

Publication number Publication date
FR786335A (fr) 1935-08-31
US2248561A (en) 1941-07-08
FR786900A (fr) 1935-09-11

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