Power control on satellite uplinks
Apparatus and method for monitoring a communications system
Television interval timer employing digital techniques
Bidirectional information transmission via a long distance video interface (LDVI) cable
Method and apparatus for television distribution system sweep testing
Vertical code verifier
Television signal amplitude detection circuit
Digital vertical sync filter
Portable sampling spectrum analyzer
ApplicationNo. 783012 filed on 10/25/1991
US Classes:348/181, Test signal generator348/476, During sync, blanking, or overscan455/67.14, Using a test signal725/144Headend
ExaminersPrimary: Peng, John K.
Assistant: Hsia, Sherrie
Attorney, Agent or Firm
International ClassH04N 017/00
AbstractA non-interference method of determining the frequency characteristics of a cable television (CATV) system adds an RF test pulse to an RF video signal in the vertical interval between equalizer pulses. A gated receiver coupled to the distribution system receives the RF video signal only during the vertical interval and extracts the envelope of the RF test pulse, with the sync pulses being attenuated. RF pulses of different frequencies within each channel of the CATV system are used to determine the frequency characteristics of each channel.