| | | | (Adjective) also "Analog". Refers to a system or signal that is continuously variable, either with infinite range or between two points. This contrasts with digitial signals or systems that can only ever be in either one state or the other, 1 or 0, "on" or "off". In analogue systems the variations/fluctuations in the signal have value and are one advantage that analogue has over digital - because the "resolution" is infinite (in theory at least) in an analogue signal and that of a digital signal can only ever be in discrete steps. This has been one of the arguments put forward by those championing the cause of vinyl music recordings over compact discs when claiming that vinyl has better tonal quality. In practice however as digital systems have become more and more complex, the line is blurring and in most cases digital is superceding analogue. Electrical/electronic systems frequently transmit their analogue signal by the means of modulating the phase or amplitude of a "carrier" wave. For example (non-digital) radio and television transmissions and telephones work in this way. The major disadvantage of analogue is the fact that any analogue signal will carry "noise", that is to say random values - errors - will creep into the signal, degrading it. The degree of noise increases with distance the signal travels, amount of times data is reproduced etc. Two aspects of digital systems are an improvement over this situation - first, any noise or degradation of the signal can be detected by the system and secondly once detected these errors can be corrected and the integrity of the signal restored. Further examples of analogue systems include the following: the mercury thermometer, the dimmer switch, the VHS video recorder. | | | |
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