Title: Frequency-selective signal receiver for communication equipments, more particularly telephone equipments

Abstract: In a frequency-selective signal receiver for receiving at least two multi-frequency group codes and equipped with a voice-frequency trap, a broad-band frequency detector and a narrow-band frequency detector are connected in series parallel relative to the frequency coded input signal whereby the receiver channels of the narrow-band frequency detector provided for each single frequency of interest are activated when a conicidence between signals of two groups occurs. Due to the short transient response time of the broad-band frequency detector, character recognition is possible after a short time. The narrow-band frequency detectors are individually adjustable so that in the signal receiver particularly threatened frequency channels can correspondingly be taken into account.

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Inventors: Rother, Klaus-Dieter (Planegg, DT)

Application Number: 399337
Filing Date: 1973-09-20
Publication_date: 1976-01-13
Assignee: Siemens Aktiengesellschaft (Munich, DT)
Primary Class(es): 379/386
Other Classes:
US Patent Ref:

3128349	Apr, 1964	Boesch et al.	179/84.
3582562	Jun, 1971	Sellari	179/18.
3582565	Jun, 1971	Beeman et al.	179/84.
3770900	Nov, 1973	Morlec	179/84.
3812432	May, 1974	Hanson	328/138.

Other Refs:
Primary Examiner: Claffy, Kathleen H.
Assistant Examiner: Popek, Joseph
Attorney: Schuyler, Birch, Swindler, McKie & Beckett