GB559555A - Frequency modulation radio receivers - Google Patents

Frequency modulation radio receivers

Info

Publication number
GB559555A
GB559555A GB11791/42A GB1179142A GB559555A GB 559555 A GB559555 A GB 559555A GB 11791/42 A GB11791/42 A GB 11791/42A GB 1179142 A GB1179142 A GB 1179142A GB 559555 A GB559555 A GB 559555A
Authority
GB
United Kingdom
Prior art keywords
frequency
output
note
audio
modulation
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
GB11791/42A
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.)
Philco Radio and Television Corp
Original Assignee
Philco Radio and Television 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 Philco Radio and Television Corp filed Critical Philco Radio and Television Corp
Publication of GB559555A publication Critical patent/GB559555A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J3/00—Continuous tuning
    • H03J3/02—Details
    • H03J3/12—Electrically-operated arrangements for indicating correct tuning
    • H03J3/14—Visual indication, e.g. magic eye

Landscapes

  • Circuits Of Receivers In General (AREA)
  • Television Receiver Circuits (AREA)

Abstract

559,555. Frequency modulation. PHILCO RADIO & TELEVISION CORPORATION. Aug. 21, 1942, No. 11791. Convention date, Oct. 21, 1941. [Class 40 (v)] To enable a frequency-modulation receiver to be accurately tuned, an audio amplitude modulation is imposed on the received wave and the tuning is adjusted until a minimum audio response is heard in the receiver, or a minimum effect observed in an indicator. As shown, the I.F. amplifier 13 is coupled to a balanced frequency discriminator, of the kind described in Specification 559,967, the output of which is fed to the audio stages. An audio note, which may arise from the unsmoothed output of a mains supply rectifier 29 is fed through a control switch 36 to the screen grid of the amplifier 13 thereby amplitude-modulating its output. When the set is accurately tuned this amplitude modulation produces little or no effect on the output of the discriminator, but when the set is off tune, the note is heard. A small condenser 35 and resistance 37 may be provided to favour harmonics of the mains frequency. The note frequency may control a visual indicator, which may be arranged to respond only to the particular note frequency employed.
GB11791/42A 1941-10-21 1942-08-21 Frequency modulation radio receivers Expired GB559555A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US559555XA 1941-10-21 1941-10-21

Publications (1)

Publication Number Publication Date
GB559555A true GB559555A (en) 1944-02-24

Family

ID=22001224

Family Applications (1)

Application Number Title Priority Date Filing Date
GB11791/42A Expired GB559555A (en) 1941-10-21 1942-08-21 Frequency modulation radio receivers

Country Status (1)

Country Link
GB (1) GB559555A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0003634A1 (en) * 1978-02-09 1979-08-22 Motorola, Inc. Method of aligning a radio receiver and means for indicating the alignment of a radio receiver

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0003634A1 (en) * 1978-02-09 1979-08-22 Motorola, Inc. Method of aligning a radio receiver and means for indicating the alignment of a radio receiver

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