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  2. Philips circle pattern - Wikipedia

    en.wikipedia.org/wiki/Philips_circle_pattern

    From 1 March 1975, the Dutch public broadcasting system also started to use the Philips circle pattern on its TV channels, replacing the monochrome RMA 1946 Resolution Chart, the electronic monochrome chequerboard test card generated by a Philips GM 2671/50 video signal generator, [141] the Philips PM5552 early colour test card, and after the ...

  3. Four-wire circuit - Wikipedia

    en.wikipedia.org/wiki/Four-wire_circuit

    In telecommunications, a four-wire circuit is a two-way circuit using two paths so arranged that the respective signals are transmitted in one direction only by one path and in the other direction by the other path. The four-wire circuit gets its name from the fact that is uses four conductors to create two complete electrical circuits, one for ...

  4. RF modulator - Wikipedia

    en.wikipedia.org/wiki/RF_modulator

    When the TV is tuned to the programmed channel, the video and audio signal of the source device is accessed. RF modulation can become difficult in a CATV system. High pass, low pass, and notch filters must be used to block certain frequencies, or channels, so that the modulator can broadcast the audio/video signal of the source device on that ...

  5. 8VSB - Wikipedia

    en.wikipedia.org/wiki/8VSB

    A modulation method specifies how the radio signal fluctuates to convey information. ATSC and DVB-T specify the modulation used for over-the-air digital television; by comparison, QAM is the modulation method used for cable. The specifications for a cable-ready television, then, might state that it supports 8VSB (for broadcast TV) and QAM (for ...

  6. Circuit diagram - Wikipedia

    en.wikipedia.org/wiki/Circuit_diagram

    A circuit diagram (or: wiring diagram, electrical diagram, elementary diagram, electronic schematic) is a graphical representation of an electrical circuit. A pictorial circuit diagram uses simple images of components, while a schematic diagram shows the components and interconnections of the circuit using standardized symbolic representations.

  7. Power dividers and directional couplers - Wikipedia

    en.wikipedia.org/wiki/Power_dividers_and...

    Directional couplers and power dividers have many applications. These include providing a signal sample for measurement or monitoring, feedback, combining feeds to and from antennas, antenna beam forming, providing taps for cable distributed systems such as cable TV, and separating transmitted and received signals on telephone lines.

  8. Low-voltage differential signaling - Wikipedia

    en.wikipedia.org/wiki/Low-voltage_differential...

    Basic LVDS circuit operation showing current flowing in a loop back to the driver and the resulting lower radiated emission (EMI) due to field coupling within the differential pair Low-voltage differential signaling ( LVDS ), also known as TIA/EIA-644 , is a technical standard that specifies electrical characteristics of a differential , serial ...

  9. Cable television - Wikipedia

    en.wikipedia.org/wiki/Cable_television

    Most cable companies require a set-top box (cable converter box) or a slot on one's TV set for conditional access module cards [2] to view their cable channels, even on newer televisions with digital cable QAM tuners, because most digital cable channels are now encrypted, or scrambled, to reduce cable service theft. A cable from the jack in the ...