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一、故障原因造成电话机杂音的故障原因虽然很多,但归纳起来主要有以下四个方面: 1.电话线路中的接头严重氧化,形成不稳定的接触电阻,导致电路中电流不稳,从而在电话机中产生较大的杂音。2.电话机回路中电阻太大。程控交换机要求回路电阻不大于2kΩ(包括电话机电阻),并保证馈电流不小于18mA。若超过该范围,则会出现杂音。3.送话器受潮后,其绝缘特性、阻抗特性发生变
First, the cause of the malfunction caused by telephone malfunction Although many, but summed up in the following four aspects: 1. The phone line connector serious oxidation, the formation of an unstable contact resistance, leading to the current instability in the circuit, which in Larger noise in the phone. 2. The resistance in the telephone circuit is too large. Program-controlled switch circuit resistance requirements of not more than 2kΩ (including phone resistance), and to ensure that the current feed is not less than 18mA. If you exceed the range, there will be noise. 3. The microphone is damp, the insulation properties, impedance characteristics change