Remote test telephone line access system

In a remote test access system for remotely testing an accessed telephone ine, said system comprising a telephone test set having an associated test set delay time, and a test set insertion switch means having a test path position and a normal signal path position for switchably inserting said test set into said telephone line in said test path position, said telephone line forming a test path through said test set when said test set is switchably inserted into said telephone line in said test path position and a normal signal path when said test set is switchably disconnected from said telephone line in said normal signal path position, said test set providing an actual test signal over said telephone line through said test path when said test set is switchably inserted therein in said test path position;

• the improvement comprising means operatively connected to said test set insertion switch means for providing a common fixed reference delay for said telephone line in both said normal signal path position and said test path position, said fixed reference delay providing a fixed delay time for all signals passing over said telephone line, and variable delay means operatively connected to said test set insertion switch means in said test path position for providing a delay for said test signal passing through said test path, said variable delay means comprising means for varying the delay time associated with a signal passing therethrough for providing a varied delay value capable of providing a matching between said fixed reference delay and the sum of said test set delay associated with the test set inserted in said delay line and said variable delay means varied delay, value, said variable delay means delaying said actual test signal passing through said variable delay means in accordance with said varied delay value of said variable delay means;
• whereby a test set may be inserted into an accessed telephone line without interrupting the timing on the telephone line for providing errorless testing on said telephone line.