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In telecommunications, the (digital) cliff effect or brick-wall effect is a sudden loss of digital signal reception.Unlike analog signals, which gradually fade when signal strength decreases or electromagnetic interference or multipath increases, a digital signal provides data which is either perfect or non-existent at the receiving end.
Test cards typically contain a set of patterns to enable television cameras and receivers to be adjusted to show the picture correctly (see SMPTE color bars).Most modern test cards include a set of calibrated color bars which will produce a characteristic pattern of "dot landings" on a vectorscope, allowing chroma and tint to be precisely adjusted between generations of videotape or network feeds.
The dish had to be pointed directly at the satellite, with nothing blocking the signal. Weaker signals required larger dishes. [4] [5] [6] The dishes worked by receiving a low-power C-Band (3.7–4.2 GHz) frequency-modulated analog signal directly from the original distribution satellite – the same signal received by cable television headends.
Television broadcast stations are located and assigned to channels so that such events are rare. Readjustment of the receiving antenna may allow more of the distant signal to be rejected, improving image quality. A local signal may travel by more than one path from the transmitter to receiving antenna.
A signal strength and readability report is a standardized format for reporting the strength of the radio signal and the readability (quality) of the radiotelephone (voice) or radiotelegraph (Morse code) signal transmitted by another station as received at the reporting station's location and by their radio station equipment. These report ...
A plain-language radio check is the means of requesting and giving a signal strength and readability report for radiotelephony (voice) communications, and is the direct equivalent to the QSA and QRK code used to give the same report in radiotelegraph communications.
A mixer in the dish-end equipment (an LNB or distribution unit) converts the received signal to the correct user band IF centre frequency for that receiver. [3] The converted transponders of the various users are then combined, and sent via the single coaxial cable to the receivers. The combined signal is tapped or split to reach every user.
A mobile phone signal (also known as reception and service) is the signal strength (measured in dBm) received by a mobile phone from a cellular network (on the downlink). Depending on various factors, such as proximity to a tower, any obstructions such as buildings or trees, etc. this signal strength will vary. Most mobile devices use a set of ...