Abstract: A method for measurement of transmission characteristics consists of supplying a test pulse to an object under test and measuring the pulse at the output of the object under test with the assistance of Fourier analysis. The test pulse is made up of a plurality of components which are equally spaced apart in frequency, and the initial phase values of each of the components are chosen so as to reduce loading of the object under test to an acceptable level both at the input of the test object and its output. Evaluation of the test pulse at the output of the object under test yields attentuation and phase shift characteristics for each component frequency. Initial phase angles for the components of the test pulse are determined by taking into consideration the likely distortion in the test object in such a manner that a minimum crest factor is attained both in the tranmitted pulse and in the pulse received at the output of the test object.

Abstract: A method for measuring the transmission characteristics of a transmission line during gaps in communications on said transmission line consists of monitoring the transmission line for a gap in communication thereon, and applying an identifier signal followed by a test pulse to the input of the transmission line when such a communications gap is recognized. An output of the transmission line is monitored and when the identifier signal is recognized, the test pulse which follows the identifier is evaluated. The test pulse is made up of a plurality of component frequencies at equally spaced intervals, and evaluation of the test pulse at the output yields the attenuation of phase characteristics of the transmission line for each component frequency, without interfering with communications on the line.

Abstract: Cross-talk attenuation characteristics and/or other transmission characteristics are measured by means of a method which applies a test pulse to the input of an object under test, the test pulse being composed of a plurality of component frequencies having predetermined amplitudes and initial phase angles, with the output of the test object being evaluated by means of Fourier analysis, using an FFT processor. The effective noise is substantially reduced by transmitting plural test pulses, and calculating the mean value of plural results produced sequentially by the FFT processor. Alternatively, the effective noise is reduced by reducing the widths of the effective pass bands of the evaluation by carrying on the evaluation over a period which exceeds the period of a single test pulse, or by setting the amplitudes of some components of the test pulse to zero and increasing the amplitudes of the remaining components.

Abstract: A method for measurement of transmission characteristics consists of supplying a test pulse to an object under test and measuring the pulse at the output of the object under test with the assistance of Fourier analysis. The test pulse is made up of a plurality of components which are equally spaced apart in frequency, and the initial phase values of each of the components are chosen so as to reduce loading of the object under test to an acceptable level. Evaluation of the test pulse at the output of the object under test yields attenuation and phase shift characteristics for each component frequency.

Abstract: A method for measuring the transmission characteristics of an object under test consists of applying a test pulse to the input of an object under test which has a filter characteristic, and evaluating the test pulse when it is produced at the output. The test pulse is made up of a plurality of component frequencies at equally spaced intervals, and the components which lie within the region of the edge of the pass band of the filter characteristic have greater amplitudes than the components which lie within the central portion of the pass band of the filter characteristic. Evaluation of the test pulse at the output of the object under test yields the attenuation and phase characteristics of the object under test for each component frequency.