| 摘要 |
A cable testing device including an oscillator designed to operate at a constant frequency and arranged to be selectively interconnected to one end of pairs of conductors in a long distance telephone cable through a transformer. Optical and/or acoustic signal generators are connected to windings on the transformer and to the pairs of conductors at their other ends at the opposite end of the cable. The signal generators permit resistance values of a known pair of conductors to be compared to resistance values of conductors tested one by one in conjunction with a return conductor of known value. These signal generators can be electrical meters or may involve a switching stage which is associated with the transformer to switch a wireless signal generator or a summing device, such as a multivibrator. |
