379 / | HD | TELEPHONIC COMMUNICATIONS |
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1 | | DIAGNOSTIC TESTING, MALFUNCTION INDICATION, OR ELECTRICAL CONDITION MEASUREMENT {12} |
2 | DF | .~> Including fault responsive disconnection of tested component |
3 | DF | .~> Of hybrid or echo suppressor or canceller |
4 | DF | .~> Of repeater |
5 | DF | .~> By loopback |
6 | DF | .~> By analysis of injected tone signal |
7 | DF | .~> For detection of eavesdropping device |
8 | DF | .~> With blocking of normal usage |
9 | DF | .~> Of centralized switching system {6} |
21 | DF | .~> Using portable test set (e.g., handset type) |
22 | DF | .~> Of trunk or long line {4} |
27 | DF | .~> Of subscriber loop or terminal {4} |
32 | DF | .~> Indication of nonstandard condition of telephone equipment {1} |