GB639966A - Improvements in superheterodyne radio-receiving apparatus - Google Patents

Improvements in superheterodyne radio-receiving apparatus

Info

Publication number
GB639966A
GB639966A GB9507/48A GB950748A GB639966A GB 639966 A GB639966 A GB 639966A GB 9507/48 A GB9507/48 A GB 9507/48A GB 950748 A GB950748 A GB 950748A GB 639966 A GB639966 A GB 639966A
Authority
GB
United Kingdom
Prior art keywords
alarm
signal
oscillator
cessation
april
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
Application number
GB9507/48A
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.)
Koninklijke Philips NV
Original Assignee
Philips Gloeilampenfabrieken NV
Philips Electronics NV
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 Philips Gloeilampenfabrieken NV, Philips Electronics NV filed Critical Philips Gloeilampenfabrieken NV
Publication of GB639966A publication Critical patent/GB639966A/en
Expired legal-status Critical Current

Links

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
    • 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
    • H03F1/52—Circuit arrangements for protecting such amplifiers
    • H03F1/54—Circuit arrangements for protecting such amplifiers with tubes only

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Circuits Of Receivers In General (AREA)

Abstract

639,966. Valve circuits for radio reception. PHILIPS ELECTRICAL, Ltd. April 5, 1948, No. 9507. Convention date, April 8, 1947. [Class 40 (vi)] A superheterodyne receiver has means (not shown) dependent on an output voltage for giving an alarm or effecting a change-over to spare apparatus on failure of the receiving apparatus. In order that the alarm or change-over shall not operate due to a cessation of the received signal, an additional oscillator 7 is provided which supplies to the input stage 2 a signal of the same frequency as the incoming signal but at a smaller amplitude. During normal reception, oscillator 7 is inhibited by intermediate frequency energy rectified at 9. On cessation of the incoming signal, reduction of the I.F. output allows oscillator 7 to supply a replacement signal sufficient to prevent operation of the alarm. If, however, the receiver is faulty, there will still be no I.F. output and the alarm will operate or new apparatus will be substituted.
GB9507/48A 1947-04-08 1948-04-05 Improvements in superheterodyne radio-receiving apparatus Expired GB639966A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL639966X 1947-04-08

Publications (1)

Publication Number Publication Date
GB639966A true GB639966A (en) 1950-07-12

Family

ID=19788990

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9507/48A Expired GB639966A (en) 1947-04-08 1948-04-05 Improvements in superheterodyne radio-receiving apparatus

Country Status (3)

Country Link
BE (2) BE481708A (en)
FR (1) FR964286A (en)
GB (1) GB639966A (en)

Also Published As

Publication number Publication date
FR964286A (en) 1950-08-09
BE401708A (en)
BE481708A (en)

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