Measurement of reflection factors of multiple path transmission cable - uses oscilloscope and sampler and pen recorder with zero position adjusted by keys

摘要

This method of measuring the reflection factors of a multiple path transmission cable uses an oscilloscope, a sampler and a pen recorder. A cable (2) containing typically twelve coaxial transmission lines (2) is connected, one line at a time, to an oscilloscope (3) provided with a control (5) which together with the display (4) gives the characteristic impedance of that line. A sampler (6) is also applied to the signal and this is connected by suitable amplifiers (10, 11) and voltage adjustment elements (12, 13) to a pen recorder (7). The recorder has a number of keys (8), each corresponding to one recorder position in one of the X-Y lines. By using these controls and the display the reflection factor is found. A uniselector may be incorporated to switch round all the lines in a cable automatically, if required.