GB782332A - Improvements in or relating to carrier-wave telephony transmitters - Google Patents

Improvements in or relating to carrier-wave telephony transmitters

Info

Publication number
GB782332A
GB782332A GB34165/55A GB3416555A GB782332A GB 782332 A GB782332 A GB 782332A GB 34165/55 A GB34165/55 A GB 34165/55A GB 3416555 A GB3416555 A GB 3416555A GB 782332 A GB782332 A GB 782332A
Authority
GB
United Kingdom
Prior art keywords
compression
speech
carrier
band
network
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
GB34165/55A
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.)
Philips Electrical Industries Ltd
Original Assignee
Philips Electrical Industries 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 Philips Electrical Industries Ltd filed Critical Philips Electrical Industries Ltd
Publication of GB782332A publication Critical patent/GB782332A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N7/00—Television systems
    • 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
    • H04B1/62—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 for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
    • H04B1/64—Volume compression or expansion arrangements

Abstract

782,332. Automatic volume control. PHILIPS ELECTRICAL INDUSTRIES, Ltd. Nov. 29, 1955 [Dec. 2, 1954], No. 34165/55. Class 40 (4). In a carrier transmission system using amplitude compression an auxiliary signal adjacent the speech band is combined with the speech signal in each channel before compression and the channel compression circuit is controlled by the joint signal. The auxiliary signal which is preferably of higher frequency than the speech band, has a level lower than that of the speech, which is adjustable. Speech currents from microphone 14, Fig. 3, are combined with the current from generator 24 in transformer 16 and modulated with a 30 kc/s. carrier in a modulator 18-21. The selected side-band is compressed in network 34-40 by a sample of the output of amplifier 27 which is taken off by a winding 43, limited as regard to surges by a biased rectifier 44 and rectified in a rectifier 45. The rectified voltage is applied to the compression network via a D.C. amplifier 49 which includes a bias battery 48 to create a " threshold." A modification wherein the compression control voltage is derived from a point in front of the compression network is also suggested.
GB34165/55A 1954-12-02 1955-11-29 Improvements in or relating to carrier-wave telephony transmitters Expired GB782332A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL782332X 1954-12-02

Publications (1)

Publication Number Publication Date
GB782332A true GB782332A (en) 1957-09-04

Family

ID=19832185

Family Applications (1)

Application Number Title Priority Date Filing Date
GB34165/55A Expired GB782332A (en) 1954-12-02 1955-11-29 Improvements in or relating to carrier-wave telephony transmitters

Country Status (5)

Country Link
BE (1) BE543273A (en)
DE (1) DE1015857B (en)
FR (1) FR1144201A (en)
GB (1) GB782332A (en)
NL (2) NL192874A (en)

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB702045A (en) * 1950-04-20 1954-01-06 Gen Electric Co Ltd Improvements in or relating to apparatus for effecting amplitude compression and expansion of electric signals and signalling systems including such apparatus
BE513414A (en) * 1951-09-12

Also Published As

Publication number Publication date
BE543273A (en)
DE1015857B (en) 1957-09-19
FR1144201A (en) 1957-10-10
NL192874A (en)
NL102594C (en)

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