SU764140A2 - Device for measuring cross-talk between line tracts of cable lines - Google Patents

Description

r6 to the input of the influential path and the measuring unit, the selective conversion UE, the first input of which is connected to the output of the influencing path, the second output from the output path, and the outputs of the selective conversion of the body assembly are connected to the outputs of the measuring unit In addition, the selective transducer node contains the first HIGH frequency amplifier, the first mixer, and the first intermediate amplifier, often. Ш, as well as series-connected e, the second high frequency amplifier,

.second mixer and second amplifier. intermediate frequency and an automatic frequency control unit AND a local oscillator, the first and second outputs of which are connected respectively to the control inputs of the first and second mixers, while the output of the first amplifier of the intermediate frequency is connected via an automatic frequency control unit to the local oscillator BJtoJuy This input is the first amplifier of high frequency

is the first input-selective conversion node, the second of which is the input of the second amplifier high frequencies, and the output No. 1 of the selective conversion node are the outputs of the first and second intermediate frequency amplifiers, and the generator is in the form of frequency HcKpeTHBax frequencies, An additional mixer, a quadrupole counter-connection, and a selective level indicator are introduced in series, with the first and second mixer being connected to the first and second doers In a number of ways, the election campaigns Shatshbnof ue a7 Sh5ge1d oppolnopolyusnyka antithewed under the schenen to the output line of the influencing tract.

The outline is a structural scheme of the proposal

devices ..

A device for measuring mutual influences between linear paths, to: abel, highways, contains generator 1, influence path 2, HSlfePH unit 3, measuring and converting unit 4, path 5, impacted, first high frequency amplifier b , the first mixer 7, the first amplifier 8 intermediate time-i rts, the second amplifier 9 high frequency, the second mixer 10, the second .. amplifier 11 intermediate frequency, block 12 automatic frequency control, local oscillator 13, additional mixer 14, quadripole 15 protbos. elect Provisional index: Level 16, linear amplifier 17 of the influencing path. .

The device works as follows.

To measure the transfer functions of mutual effects at the transmitting end of the generator trunk, torus 1 is connected to the influencing Path 2. Output; one resistance of the generator 1 must be significantly greater than the equivalent resistance of the influencing Path 2 at its activation point, so as not to disrupt the system operation connection. The frequency of the measuring signal of the generator 1 is determined by

formula ----: -., -.,.,

Claims (1)

“C 4p + 12 (0.1-g 0.14) kHz, where h is the number of the communication channel located in the operating frequency range of the compression system below the inter-channel spacing, in which meter the measurement is performed (plus sign for the back of the center sequence) communication channels in the linear path, and a minus sign — in direct). The output level of generator 1 is set so that the level of the measurement signal, a, applied to the input of the influence path 2, does not exceed 20-15 dB. and thus, the quality of the communication channels adjacent to the inter-channel gap, to which the measurement signal is applied, did not improve. At the receiving end, the StasTra and the input of the first high-frequency amplifier 6 are connected to the influence path 2, the input of the second high-frequency amplifier 9 to the output of the path 5 affected. The first and second amplifiers of b, 9 high frequencies provide a high-resistance input, attenuation or amplification of incoming signals if necessary, preliminary selection in frequency, as well as a transition from symmetrical circuits of the line paths of the communication line to an imbalance; In the first and second mixers 7, 10, as which can be used, for example, a double balanced modulator, the signal multiplied from the first and second amplifiers 6, η 9 high Ota zayisymosti in the channel and voltage oscillator 13. The selection bbnovny iemerytolnyh g roiskhodit signals in the electoral eleL4ontazs lieipsoro and second amplifiers 11 August intermediate frequency. The special feature of the jBToporo amplifier 11 intermediate Shsty tst'byf in its ultra-narrowness and high selectivity (passband ± 2 Hz at 3 dB, attenuation at detuning from the resonant frequency at i50 Hz is not less than 60 dB) necessary for extracting very low 3 rTi telegrams of very low level path 5 subject to influence in the background of information signals; transmitted over communication channels. This is ensured by using multi-stage quartz filters in the second intermediate frequency amplifier 11. To maintain fine tuning of the selective transducer node 4 to the frequency of the measuring signal, taking into account the instability of the Late frequency relative to the frequency of the local oscillator 13, block 12 automatically adjusts the frequency, the input of which is connected to the output of the first amplifier 8 intermediate frequency, and the output to the input the local oscillator 13. As a reference signal, a high level intermediate frequency signal is used. From the outputs of the first and second amplifiers 8, 11 of the intermediate frequency, the measurement signals are fed to the corresponding inputs of the measuring unit 3, in which the measurement of the relations of the complex amplitudes of two sinusoidal voltages is carried out. Ensuring that the quality of the communication channels of the influence tract 2 adjacent to the inter-channel frequency gap, to which the measuring signal is fed, is maintained, is carried out as follows: The signal from the output of the first intermediate-frequency amplifier 8 goes to the first input of the additional mixer 14, to the second input of which a signal is supplied from the first output of the local oscillator 13. As a result of multiplying these signals, the output of the additional mixer 14 produces a signal whose frequency is exactly equal to the frequency of the measuring signal . By means of adjustable elements of a three-pole 15 in connection with; the input of which receives the reconstructed signal, its amplitude and phase are selected so that at the output of the linear amplifier 17 of the impacting waste get the greatest attenuation of the measuring influence signal. This moment is fixed by the smallest indications of a selective level indicator 16, which can be used as a device specially made for this device, or serially produced devices used in the operation of cable magneaters. As adjustable elements of the quadripole 15 counter-coupling, variable resistors can be used Condensation, Le liable delay lines in combination with the first. After tuning to the measuring signal of the device at the transmitting end to perform measurements, the level of the signal supplied to the input of the influencing path increases to -5 dB, and at the end, if necessary, signal attenuation is introduced in the first high-frequency amplifier, but It is required to have a magnitude of the transmission coefficient of the adjustable elements of the quadrupole 15 opposed to the same magnitude. Formula of the invention. A device for measuring the mutual influences between the linear paths of cable trunks according to autor. 1303, characterized in that in order to ensure measurements without reducing the quality of communication through the channels of the influencing linear path, an additional mixer, a quadruple counter-BAND, and a selective level indicator are introduced in series, the first and second inputs of the additional mixer being connected respectively to the first and additional outputs the selective-converting node, and the output of the quadrupole counter-coupling is connected to the output of the linear amplifier of the influence path.