SU680045A1 - Method of measuring phase distortions occurring as a result of reproduction of recording from magnetic tape - Google Patents

Description

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The invention relates to the field of information accumulation.

A known method of measuring phase distortions of the reproduction result from a magnetic recording medium by reproducing measurement signals recorded on different recording tracks, and plotting their characteristics of mutual phase distortions 1. The known method provides a relatively high accuracy of measuring the phase distortions of the reproduction result from a magnetic recording medium. A disadvantage of the known method / 5a is the considerable complexity of the measurement process.

There is also known a method for measuring phase distortions of the reproduction result from a magnetic recording medium by reproducing the measurement signals recorded on different recording tracks and determining their mutual autocorrelation function and the characteristics of mutual phase distortions 2.

This method provides a measurement of phase distortion of the result; reproducing a magnet from a medium. Recording is relatively simple. The disadvantage of it is

in large measurement error.

The purpose of the invention is to reduce the frequency measurement of the phase distortion of the reproduction result from the magnetic recording medium.

This is achieved due to the fact that, according to the proposed method, the maximum of the mutual autocorrelating function of the reproduced measuring signals is extracted, according to which the latter are mutually delayed, while the characteristic of the mutual phase distortions is determined

5 is produced in a reciprocal phase of mutually delayed reproduced measurement signals.

The drawing shows one of the possible variants of the device for implementing the proposed method.

The device contains a measuring signal generator 1 connected to recording magnetic heads 2 interfaced to a carrier.

5 magnetic recordings, for example from a magnetic tape. The magnetic recording medium is also interfaced with reproducing magnetic heads 3 connected to the delay unit 4, connected via the evaluation unit 5 of the mutual

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Noah phase with output bus b. The reproducing magnetic heads 3 are also connected to a correlometer 7, connected through a maxiglum extraction unit 8 of the mutual autocorrelation function to the control input of the delay unit 4.

Measurement of the phase distortion of the playback result from the magnetic recording medium according to the proposed method is as follows. On different recording tracks of a magnetic recording carrier, measurement signals are recorded, such as pulsed or white noise signals, which are reproduced by reproducing magnetic heads 3. The reproduced measuring signals are transmitted from reproducing magnetic heads 3 to the correlometer 7 and to the delay unit four . In the correlometer 7 occurs. 9determination of the mutual autocorrelation function of the reproduced measurement signals. The delay unit 4 produces a mutual delay of the reproduced measuring signals. This mutual delay is produced according to the maximum of the mutual autocorrelation function of the reproduced measurement signals. The latter is selected by means of a maximum separation unit 8 of the mutual autocorrelation function, in block 5, the characteristic of the phase distortion of the reproduced measurement signals is determined. This is opfi80045

The determination is made according to the mutual phase of the mutually delayed reproduced measuring signals from the delay unit 4.

The use of the invention makes it possible to significantly reduce the measurement error of the phase distortion of the reproduction result from the magnetic recording medium.

Claims (2)

1. USSR author's certificate number 489145, cl. G 11 B 5/02, 1974. 2. USSR author's certificate number 526016, cl. G 11 B 27/36, 1974.