GB549770A - Improvements in scanning radio receivers - Google Patents

Improvements in scanning radio receivers

Info

Publication number
GB549770A
GB549770A GB2755/41A GB275541A GB549770A GB 549770 A GB549770 A GB 549770A GB 2755/41 A GB2755/41 A GB 2755/41A GB 275541 A GB275541 A GB 275541A GB 549770 A GB549770 A GB 549770A
Authority
GB
United Kingdom
Prior art keywords
voltage
oscillator
tuning
frequency
tone
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
GB2755/41A
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.)
Individual
Original Assignee
Individual
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 Individual filed Critical Individual
Publication of GB549770A publication Critical patent/GB549770A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/18—Automatic scanning over a band of frequencies
    • H03J7/20—Automatic scanning over a band of frequencies where the scanning is accomplished by varying the electrical characteristics of a non-mechanically adjustable element
    • H03J7/22—Automatic scanning over a band of frequencies where the scanning is accomplished by varying the electrical characteristics of a non-mechanically adjustable element in which an automatic frequency control circuit is brought into action after the scanning action has been stopped
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/02—Automatic frequency control
    • H03J7/04—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant
    • H03J7/042—Automatic frequency control where the frequency control is accomplished by varying the electrical characteristics of a non-mechanically adjustable element or where the nature of the frequency controlling element is not significant with reactance tube
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03J—TUNING RESONANT CIRCUITS; SELECTING RESONANT CIRCUITS
    • H03J7/00—Automatic frequency control; Automatic scanning over a band of frequencies
    • H03J7/18—Automatic scanning over a band of frequencies
    • H03J7/20—Automatic scanning over a band of frequencies where the scanning is accomplished by varying the electrical characteristics of a non-mechanically adjustable element

Abstract

549,770. Wireless receiving systems. WHITE, S. Y. Feb. 28, 1941, No. 2755. Convention date, Feb. 29, 1940. [Class 40 (v)] A radio receiver system includes a thermionic reactance for automatically and continuously tuning a receiver over a range of frequencies, a director device, and a tone operated relay for conditioning the director device to render the continuous tuning ineffective in response to the reception of: a carrier frequency within the range and identified: by modulation with a predetermined tone. Fig. 2 shows the invention applied to a superheterodyne receiver in which a part of the output of the I.F. amplifier is fedby lead 23 to a valve VT1 in the output of which are circuits TC1, TC2 tuned to frequencies on either side of the intermediate frequency so that the differential. voltage from load resistors R1, R2 of diodes VT2 indicates, both by sign and amplitude, departures from tuning. This voltage is fed by lead 22 to the grid of a valve VT4 arranged as a reactance in the circuit of a beat oscillator VT3 supplying the mixer 5, and varies the oscillator frequency to correct departures from tuning. A low-frequency scanning oscillator VT5, VT6 also supplies to lead 22 a voltage which continuously: sweeps the oscillator frequency over about 1 per cent of its range to facilitate finding a station. The scanning oscillator voltage is however small and is entirely swamped by the voltage from VT2 on receipt of a signal and so the tuning remains fixed. On stoppage of the signal, the scanning is resumed. In some cases the scanning oscillator can be omitted and by closing a switch SW2 a kind of random scanning is performed by the fluctuating noise voltages in the output of the audio-frequency amplifier VT7. The circuit is arranged so as only to lock in to a carrier which is modulated by a definite tone, by the provision of a valve VT10 which normally conducts and so blocks VT1 by lowering the screen grid voltage. On receipt of a signal modulated by the correct tone, energy is taken. from the audio stage VT7 and selected by tone filter TC3, TC4 where, after amplification at VT8, it is rectified at 18, 19 to provide a negative voltage which is applied to the grid' of the valve VT10. This blocks VT10 and so unblocks VT1, allowing the circuit to lock on to the selected carrier: Specification 549,769 is referred to.
GB2755/41A 1940-02-29 1941-02-28 Improvements in scanning radio receivers Expired GB549770A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US321378A US2283523A (en) 1940-02-29 1940-02-29 Scanning radio receiver

Publications (1)

Publication Number Publication Date
GB549770A true GB549770A (en) 1942-12-07

Family

ID=23250368

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2755/41A Expired GB549770A (en) 1940-02-29 1941-02-28 Improvements in scanning radio receivers

Country Status (4)

Country Link
US (1) US2283523A (en)
BE (2) BE442116A (en)
FR (1) FR882608A (en)
GB (1) GB549770A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2450018A (en) * 1943-05-07 1948-09-28 Standard Telephones Cables Ltd Radio monitoring system
US2486551A (en) * 1944-10-04 1949-11-01 Philco Corp Automatic tuning electric system

Families Citing this family (27)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2444151A (en) * 1942-11-16 1948-06-29 Rca Corp Scanning receiver for detecting signals of unknown frequency
US2490022A (en) * 1943-09-08 1949-12-06 Tung Sol Lamp Works Inc Secret signaling system
US2454265A (en) * 1943-11-06 1948-11-16 Sperry Corp Automatic frequency control system
US2627024A (en) * 1944-04-21 1953-01-27 Jr Persa R Bell Automatic frequency control
US2532872A (en) * 1944-05-26 1950-12-05 Honeywell Regulator Co Frequency responsive measuring and controlling apparatus
US2543072A (en) * 1944-06-09 1951-02-27 Sperry Corp Automatic range gate
US2470843A (en) * 1944-10-04 1949-05-24 Philco Corp Stop-on carrier tuner
US2507735A (en) * 1944-11-02 1950-05-16 Rca Corp Automatic tuning control apparatus
US2704809A (en) * 1945-06-14 1955-03-22 Williams Frederic Calland Wireless signalling systems
US2693529A (en) * 1945-11-30 1954-11-02 Alvin M Marks Fundamental tuning device
NL133065B (en) * 1946-06-21
US2560312A (en) * 1947-10-03 1951-07-10 Philco Corp Tuning aid for radio receivers
US2660663A (en) * 1947-10-24 1953-11-24 Nielsen A C Co Search signal apparatus for determining the listening habits of wave signal receiverusers
US2660511A (en) * 1947-10-24 1953-11-24 Nielsen A C Co Lockout and recycling device for an apparatus for determining the listening habits of wave signal receiver users
US2510095A (en) * 1948-04-29 1950-06-06 Int Standard Electric Corp Automatic frequency control system
US2553368A (en) * 1950-01-07 1951-05-15 Philco Corp Automatic frequency control for television receivers
US2694141A (en) * 1951-12-22 1954-11-09 Bell Telephone Labor Inc Radiant energy signaling system
US2856519A (en) * 1952-10-11 1958-10-14 Gen Precision Lab Inc Automatic signal frequency tracker, with search and hold-during-fade provisions
US2891245A (en) * 1953-11-02 1959-06-16 John H Coogan Signal tracking device
US3041451A (en) * 1954-03-05 1962-06-26 Joseph T Laing Automatic frequency search and following receiver
US2882391A (en) * 1954-09-07 1959-04-14 Gen Motors Corp Electric radio tuner
US3701025A (en) * 1954-11-02 1972-10-24 Us Navy Selective signal tuning device
US2979706A (en) * 1956-07-02 1961-04-11 Avery H Simon Radio warning system
US2977465A (en) * 1956-12-24 1961-03-28 Raytheon Co Frequency-scanning radio receivers
US3068416A (en) * 1957-02-07 1962-12-11 Sperry Rand Corp Communication system
US2989622A (en) * 1958-12-29 1961-06-20 Bell Telephone Labor Inc Hybrid sideband frequency modulation system
JPS59153178A (en) * 1983-02-21 1984-09-01 Advantest Corp Signal detector

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2450018A (en) * 1943-05-07 1948-09-28 Standard Telephones Cables Ltd Radio monitoring system
US2486551A (en) * 1944-10-04 1949-11-01 Philco Corp Automatic tuning electric system

Also Published As

Publication number Publication date
BE442117A (en)
FR882608A (en) 1943-06-09
BE442116A (en)
US2283523A (en) 1942-05-19

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