Apparatus for determining disturbances along electrical lines utilizing the impulse reflection method including controllable equalizing means comprising a two-channel amplifier

Claim 1

APPARATUS FOR USE WITH AN ELECTRICAL TRANSMISSION LINE UNDER TEST, FOR TESTING IMPEDANCE IRREGULARITIES THEREIN, COMPRISING A SOURCE OF CONTROLLING IMPULSES, MEANS FOR GENERATING TEST IMPULSES AT A GIVEN RATE FOR APPLICATION TO SAID TRANSMISSION LINE, SAID CONTROLLING IMPULSES BEING SYNCHRONIZED WITH SAID TEST IMPULSES, A CATHODE RAY OSCILLOSCOPE HAVING A CONTROL GRID, HORIZONTAL AND VERTICAL DEFLECTION MEANS FOR VISUALLY INDICATING THE RESULTS OF THE TEST, MEANS FOR GENERATING A TIME DEFLECTION VOLTAGE FOR SAID HORIZONTAL DEFLECTION MEANS, CIRCUIT MEANS CONNECTED TO SAID TRANSMISSION LINE BETWEEN SAID TEST IMPULSE GENERATOR AND SAID OSCILLOSCOPE CONNECTING THE LINE AND THE VERTICAL DEFLECTION MEANS OF SAID OSCILLOSCOPE INCLUDING TIME-CONTROLLABLE EQUALIZING MEANS FOR EQUALIZING THE DISTORTION OF SAID TEST IMPULSES, SAID EQUALIZING MEANS COMPRISING A TWO-CHANNEL AMPLIFIER, THE FIRST CHANNEL OF SAID AMPLIFIER HAVING A GAIN-FREQUENCY CHARACTERISTIC FOR EQUALIZING A SPECIFIC LENGTH OF SAID LINE, THE SECOND CHANNEL OF SAID AMPLIFIER HAVING A GAIN INDEPENDENT OF FREQUENCY AND EQUAL TO THE GAIN OF SAID FIRST CHANNEL FOR THE LOWEST FREQUENCIES, THE INPUTS AND OUTPUTS OF SAID FIRST AND SECOND CHANNELS BEING CONNECTED IN PARALLEL, PHASE SHIFTING MEANS IN SAID SECOND CHANNEL FOR EQUALIZING THE PHASE SHIFT PRODUCED IN SAID FIRST CHANNEL, A MIXING DEVICE CONNECTED TO THE OUTPUTS OF SAID FIRST AND SECOND CHANNELS,