| 摘要 |
PURPOSE:To test completely a relative frequency response, by changing the amplitude and the frequency of sine wave pulses which are added to plural sequence pulses transmitted to a transmission line, to circulate them again. CONSTITUTION:Plural sequence pulses are given by a pseudo random binary sequence generator 20, and the generation of a pulse in a preliminarily determined position is inhibited by output amplifier and pulse eliminator 24 and 37. The eliminated pulse is substituted with a variable pulse from a variable pulse generator 26, and the frequency or the amplitude is changed. Sequence pulses including the variable pulse are applied to a sample reproducer through a transformer 14 and are supplied to a data input amplifier and clock reproducing circuit 36 through a transformer 18 and are led to an error detector 44. In case of the test, the variable pulse is held in a fixed position of a transmitted test pattern, and the frequency or the amplitude is changed until a threshold for this position is detected. |
