US2038918A - Wireless receiver - Google Patents

Wireless receiver Download PDF

Info

Publication number
US2038918A
US2038918A US447693A US44769330A US2038918A US 2038918 A US2038918 A US 2038918A US 447693 A US447693 A US 447693A US 44769330 A US44769330 A US 44769330A US 2038918 A US2038918 A US 2038918A
Authority
US
United States
Prior art keywords
frequency
amplifier
band
receiver
detector
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
US447693A
Other languages
English (en)
Inventor
Bailey Christopher Edm Gervase
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
Application filed by RCA Corp filed Critical RCA Corp
Application granted granted Critical
Publication of US2038918A publication Critical patent/US2038918A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/06—Receivers
    • H04B1/16—Circuits
    • H04B1/26—Circuits for superheterodyne receivers

Definitions

  • the present invention relates to wireless receivers.
  • the circuit arrangement is such that the receiver is adapted to operate within one band of wave-lengths as a straight receiver (that is to say the received modulated high frequency oscillations are amplified and detected without the production of an intermediate high frequency) whilst the receiver is adapted to operate within another band of wave-lengths as a supersonic heterodyne receiver.
  • the same tuned circuits adjustable by the same ganged controls, may be used for both bands of wave-length.
  • the receiver is to work over the band of wave-lengths from 200 to 600 metres, that is, from 1500 to 500 kilocycles, as a straight receiver and over the band from 1000 to 2000 metres, that is, from 300 to kilocycles,
  • the system comprises an aerial or antenna circuit I having as potentiometer 2 shunted across its terminals, a local oscillator 3 whose output circuit is coupled with the grid circuit of first detector valve 4, a multistage amplifier 5, 6, I, followed by a second detector 8 whose output is connected to a low frequency amplifier 9, and translating device such as a loudspeaker, ID.
  • the thermionic valves or tubes 5, 6, l of the multi-stage amplifier are coupled by tuned circuits ll, l2, l3 and the neutralization of each stage is efiected by the use of screened grid four-electrode tubes. All the tuned circuits are controlled by the operation of a single knob which is in mechanical connection with a tuning condenser in each of the tuned circuits.
  • the frequency to which the circuits H, 12, I3 can be tuned is made adjustable over the band from 500 to 1500 kilocycles.
  • the switches l4, I5 When it is desired to receive signals within the higher frequency band, the switches l4, I5, it, which are preferably interlocked soas to be operable by the same member, are operated so as to connect the sliding contact of the potentiometer directly to the input of the multi-stage amplifier, and to effectively disconnect the oscillator 3 and first detector 4 from the remainder of the system.
  • The. receiver is now in a condition for straight reception, the high frequency oscillations received by the aerial circuit being amplified by the valves 5, 6, l and detected by the valve 8 in the usual way.
  • the circuits ll, l2, l3 are, of course, tuned to the frequency of the received signal.
  • the switches l4, l5, 16 are operated so as to remove the connection between the potentiometer contact and the amplifier input, and to connect the former point to the grid circuit of the first detector 4'.
  • the output circuit I! of the first detector is coupled to the input of the amplifier, and the plate of the local oscillator 3 is connected to a point on the high tension source.
  • the receiver is now in a condition for supersonic-heterodyne reception.
  • the oscillations produced in the output circuit I8 of the local oscillator are transferred to the grid circuit of the first detector 4, and the resulting beat oscillation is detected and transferred to the amplifier 5, 6, l, which now acts as the intermediate frequency amplifier.
  • the frequency of the local oscillations is so chosen that the resulting intermediate frequency band covers the same range as the frequency band covered by the tuned circuits H, I2 and 13.
  • the circuit I 8 may be tuned to produce a local oscillation of a frequency of 600 kilocycles.
  • this will give over the band of received signals between 150 and 300 kilocycles an intermediate frequency band extending from 750 to 900 kilocycles.
  • the oscillatory circuits associated with the local oscillator 3 and the first detector 4 are not tunable, the requisite tuning of the receiver being accomplished by means of circuits H, l2 and I3.
  • the receiver is thus tunable over both frequency bands by means of the single control member operating the circuits ll, 12, and I3, and a suitable double scale reading in kilocycles or metres may be provided upon this single control member.
  • a signal receiving system including in combination, a fixed tuned first detector, a signal source therefor, a fixed tuned local oscillator coupled therewith to produce intermediate frequency signals by interaction in the first detector, a variably tunable amplifier having a tuning range whereby it is responsive to signals in a band of intermediale frequencies produced by the interaction in the first detector, of received signals in a band of relatively low radio frequencies and oscillations from the local oscillator, and switching means for disconnecting the first detector, removing anode potential from the local oscillator and connecting the amplifier with the signal source, whereby said amplifier may directly be tuned independently of the first detector in the reception and amplification of signals of a different frequency range from said signal source.
  • a signal receiving system wherein the amplifier includes a plurality of stages the tuning of which is adjusted by a single cont-rolling member.
  • a signal receiving system in which the frequency of the local oscillator is such that the sum frequency signals, produced through interaction between oscillations therefrom and signals in the band of relatively low radio frequencies, fall within the band over which the amplifier is tunable.
  • an intermediate frequency amplifier having a plurality of electron tube amplifier circuits simultaneously tunable over a predetermined relatively wide frequency range
  • electron tube frequency changer means comprising a detector and an oscillator having fixed tuning, a signal source including a circuit having fixed tuning, and switching means for simultaneously connecting said intermediate frequency amplifier with the frequency changer means, connecting the frequency changer means with said circuit and energizing the oscillator of said frequency changer means, and said switching means having an alternative position for de-energizing said oscillaior and connecting said intermediate frequency amplifier with said circuit to the exclusion of the detector.
  • a multi-stage electron tube intermediate frequency amplifier means for simultaneously tuning a plurality of the said amplifier stages over the same frequency range, a signal receiving circuit connected to said amplifier having a frequency response characteristic such that the amplifier provides the signal selecting means therefor, an electron tube oscillator and detector having fixed tuned circuits for producing intermediate frequency signals within a frequency band included in the tuning range of the intermediate frequency amplifier, and means for simultaneously energizing said oscillator, connecting said detector with said signal receiving circuit and said amplifier with the detector output circuit.
  • a multi-stage electron tube intermediate frequency amplifier including a local electron tube oscillator having fixed tuned frequency determining circuits and having an anode circuit, and means for simultaneously removing anode potential from said circuit and connecting said intermediate frequency amplifier with a signal source other than said frequency changer means.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Input Circuits Of Receivers And Coupling Of Receivers And Audio Equipment (AREA)
  • Superheterodyne Receivers (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
  • Toys (AREA)
US447693A 1929-05-01 1930-04-26 Wireless receiver Expired - Lifetime US2038918A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB13615/29A GB331969A (en) 1929-05-01 1929-05-01 Improvements in or relating to wireless receivers

Publications (1)

Publication Number Publication Date
US2038918A true US2038918A (en) 1936-04-28

Family

ID=10026253

Family Applications (1)

Application Number Title Priority Date Filing Date
US447693A Expired - Lifetime US2038918A (en) 1929-05-01 1930-04-26 Wireless receiver

Country Status (3)

Country Link
US (1) US2038918A (de)
DE (1) DE574010C (de)
GB (1) GB331969A (de)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2601475A (en) * 1948-08-28 1952-06-24 Rca Corp Frequency converter for am-fm receivers

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2601475A (en) * 1948-08-28 1952-06-24 Rca Corp Frequency converter for am-fm receivers

Also Published As

Publication number Publication date
GB331969A (en) 1930-07-17
DE574010C (de) 1933-04-07

Similar Documents

Publication Publication Date Title
US2141756A (en) Multirange receiver
US2151810A (en) Superheterodyne receiver
US1712051A (en) Radio signaling system
US2280521A (en) Radio receiver
US2038918A (en) Wireless receiver
US2540532A (en) Superheterodyne receiver with compensation for mistuning caused by automatic volume control
US2902598A (en) Double conversion multi-band tuning unit
US1896065A (en) Selective circuit for superheterodyne radioreceivers
US2058411A (en) Radio receiver
US2155126A (en) Sound and television receiving system
US1850831A (en) Selective radioreceiver
US2100605A (en) Radio receiving system
US2032675A (en) Radio receiver
US2075526A (en) Radio signal receiving system
US2783373A (en) Superheaterodyne receiver using resistance-capacitance tuning in local oscillator and radio frequency stage
US1819299A (en) Tuning system
US3372337A (en) Image frequency attenuation circuit
US2175320A (en) Remote control device for radio receivers
US1987984A (en) Adjacent channel selectivity
USRE19765E (en) Badioreceiveb
US1933778A (en) Radio receiving system
US2066940A (en) Radio receiving system
US2570016A (en) Superheterodyne receiving circuit arrangement
US2022805A (en) Radio receiver
US1904605A (en) Crystal rejector circuit