我段在养路线上使用了GC－6程控共线电话汇接机（简称GC－6汇接机），发现用户呼叫长途台时听不到回铃音、长途台夜铃不响；话务员应答后，应答灯不灭等现象，影响了正常通信。经试验，采取增加GC－6汇接机与长途台间接口电路（下图）的方法，可克服上述问题。电路说明：①当GC I use the GC-6 program-controlled collinear telephone tandem machine (referred to as GC-6 tandem machine) on the maintenance route, and found that the user can not hear the ringback tone when calling the long distance station, and the night bell of the long-distance station does not ring; the operator answers After the answer light immortality and other phenomena, affecting the normal communication. After testing, to increase GC-6 tandem aircraft and long-distance Taiwan interfacing circuit (below) method to overcome the above problems. Circuit Description: ① when GC