GB1469127A - Vhf radio broadcast system - Google Patents

Vhf radio broadcast system

Info

Publication number
GB1469127A
GB1469127A GB2548374A GB2548374A GB1469127A GB 1469127 A GB1469127 A GB 1469127A GB 2548374 A GB2548374 A GB 2548374A GB 2548374 A GB2548374 A GB 2548374A GB 1469127 A GB1469127 A GB 1469127A
Authority
GB
United Kingdom
Prior art keywords
differential amplifier
frequency
announcement
harmonic
june
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
GB2548374A
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.)
Blaupunkt Werke GmbH
Original Assignee
Blaupunkt Werke GmbH
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 Blaupunkt Werke GmbH filed Critical Blaupunkt Werke GmbH
Publication of GB1469127A publication Critical patent/GB1469127A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G08—SIGNALLING
    • G08G—TRAFFIC CONTROL SYSTEMS
    • G08G1/00—Traffic control systems for road vehicles
    • G08G1/09—Arrangements for giving variable traffic instructions
    • G08G1/091—Traffic information broadcasting
    • G08G1/094—Hardware aspects; Signal processing or signal properties, e.g. frequency bands

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Radio Relay Systems (AREA)
  • Circuits Of Receivers In General (AREA)

Abstract

1469127 Testing system BLAUPUNKTWERKE GmbH 7 June 1974 [9 June 1973] 25483/74 Heading G1U [Also in Division H4] In a broadcast traffic information system incorporating a number of broadcasting stations which may each transmit in addition to normal programme entertainment, traffic announcements to motorists, each station radiates a pilot tone, preferably at 57 kc/s, and each such pilot tone is modulated by a frequency at or below the VHF transmission band identifying the particular transmitting station. When an announcement is actually to be transmitted, an additional modulating frequency which is the second harmonic of the identifying frequency and is phase locked to it is also transmitted - this can be detected to indicate the occurrence of the announcement. The detecting arrangement in the receiver operates by differentiating the demodulated signal, applied at 10, then, after amplification at 12, applying the demodulated signal via an integrating network 24, 26 to one input 25 of a differential amplifier. The opposite peak values of the differentiated signal are also detected by diode-capacitor arrangements 17-18 and 16-19 and their difference applied to the other side 27 of the differential amplifier. In the presence of the second harmonic, the differential amplifier is unbalanced and the signal applied via transistor 29 turns on the transistor 34 and illuminates the lamp 35.
GB2548374A 1973-06-09 1974-06-07 Vhf radio broadcast system Expired GB1469127A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19732329572 DE2329572A1 (en) 1973-06-09 1973-06-09 VHF TRAFFIC SYSTEM

Publications (1)

Publication Number Publication Date
GB1469127A true GB1469127A (en) 1977-03-30

Family

ID=5883603

Family Applications (1)

Application Number Title Priority Date Filing Date
GB2548374A Expired GB1469127A (en) 1973-06-09 1974-06-07 Vhf radio broadcast system

Country Status (5)

Country Link
DE (1) DE2329572A1 (en)
FR (1) FR2232888A1 (en)
GB (1) GB1469127A (en)
IT (1) IT1013413B (en)
SE (1) SE7407547L (en)

Also Published As

Publication number Publication date
SE7407547L (en) 1974-12-10
DE2329572A1 (en) 1975-01-02
IT1013413B (en) 1977-03-30
FR2232888A1 (en) 1975-01-03

Similar Documents

Publication Publication Date Title
GB550193A (en) Improvements in and relating to multiplex frequency-modulation systems
AU6265299A (en) Combined advertising and entertainment system network
GB536383A (en) Improvements in frequency modulation systems for radio signalling
KR840008240A (en) FM stereo radio broadcasting system
GB529984A (en) Improvements in or relating to radio transmission systems employing pulse modulation
GB582044A (en) Improvements in multiplex radio systems
ES414568A1 (en) Apparatus for distinguishing between various fm broadcast multiplex transmissions
ES8304388A1 (en) UHF transmitter for a traffic information radio broadcasting system.
ES344425A1 (en) Transmission system
GB980721A (en) Improvements in interrogator-responder signalling systems
US4124779A (en) Dual channel communications system particularly adapted for the AM broadcast band
EP0130692A3 (en) A technique for the time frequency multiplexing of three television signals
GB1469127A (en) Vhf radio broadcast system
ES457535A1 (en) Compatible am stereo broadcast system including transmitter and receiver
ES467246A1 (en) Radio broadcasting system with code signaling
US3048661A (en) Multiplex communication receiver
GB1391289A (en) Four channel stereophonic system
FR2266985A1 (en) Radio communication method for service conversations - has message and distance monitoring signal transmission in digital form
GB461749A (en) Improvements in or relating to systems of radio transmission and reception
GB413647A (en) Improvements in or relating to carrier wave transmission systems
JPS55136740A (en) Receiver for multiplex signal
GB1043232A (en) Improved wired broadcasting systems and apparatus therefor
US4194088A (en) Modulation monitor for AM stereophonic broadcasts
ES389339A1 (en) Road condition broadcasting
GB1158918A (en) Colour Television System

Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee