GB625449A - Improvements relating to means for tuning angle-modulated carrier wave receivers - Google Patents

Improvements relating to means for tuning angle-modulated carrier wave receivers

Info

Publication number
GB625449A
GB625449A GB32931/46A GB3293146A GB625449A GB 625449 A GB625449 A GB 625449A GB 32931/46 A GB32931/46 A GB 32931/46A GB 3293146 A GB3293146 A GB 3293146A GB 625449 A GB625449 A GB 625449A
Authority
GB
United Kingdom
Prior art keywords
tube
voltage
grid
amplitude
nov
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
GB32931/46A
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.)
Marconis Wireless Telegraph Co Ltd
BAE Systems Electronics Ltd
Original Assignee
Marconis Wireless Telegraph Co Ltd
Marconi Co Ltd
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 Marconis Wireless Telegraph Co Ltd, Marconi Co Ltd filed Critical Marconis Wireless Telegraph Co Ltd
Publication of GB625449A publication Critical patent/GB625449A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03G—CONTROL OF AMPLIFICATION
    • H03G3/00—Gain control in amplifiers or frequency changers
    • H03G3/20—Automatic control
    • H03G3/22—Automatic control in amplifiers having discharge tubes
    • H03G3/26—Muting amplifier when no signal is present or when only weak signals are present, or caused by the presence of noise, e.g. squelch systems
    • H03G3/28—Muting amplifier when no signal is present or when only weak signals are present, or caused by the presence of noise, e.g. squelch systems in frequency-modulation receivers ; in angle-modulation receivers

Landscapes

  • Noise Elimination (AREA)

Abstract

625,449. Frequency modulation ; radio receiving circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Nov. 6, 1946, No. 32931. Convention date, Nov. 6, 1945. [Class 40 (v)] In a frequency modulation receiver wherein audio-indication is given of correct tuning, a limiter tube 4 is arranged to provide an interstation noise squelch voltage which can be utilized to render an audio amplifying tube 37 non-conductive when the receiver is detuned from the incoming signal. As the F.M. signal amplitude at input circuit 3 increases a voltage is developed across R1, dependent on the amplitude of the F.M. signal energy, which proportionately biasses the grid 8 of the limiter tube 4. Since the plate current of tube 4 varies inversely to the voltage across R1, the voltage developed across a resistance R2 will also vary inversely to that of R1. This voltage is applied to the grid of the output tube 37 in that when tuned to the centre frequency, i.e. maximum amplitude of F.M. signal energy, no extra bias is applied to the grid 36, but when off-tune, extra bias is applied so as to mute the tube between stations. Specification 489,094 is referred to.
GB32931/46A 1945-11-06 1946-11-06 Improvements relating to means for tuning angle-modulated carrier wave receivers Expired GB625449A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US625449XA 1945-11-06 1945-11-06

Publications (1)

Publication Number Publication Date
GB625449A true GB625449A (en) 1949-06-28

Family

ID=22043195

Family Applications (1)

Application Number Title Priority Date Filing Date
GB32931/46A Expired GB625449A (en) 1945-11-06 1946-11-06 Improvements relating to means for tuning angle-modulated carrier wave receivers

Country Status (1)

Country Link
GB (1) GB625449A (en)

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