SU432405A1 - DEVICE FOR MEASURING THE DEVELOPMENT RATE OF FREQUENCY - Google Patents

Description

This invention relates to the field of radio metering technology.

The known devices for measuring the speed of frequency deviation, which contain a delay line, an amplifier and a recorder, do not provide the possibility of measuring the frequency deviation in any part of the frequency deviation and possess signaling capability.

In order to make it possible to measure the rate of change of frequency in any part of the frequency deviation and increased resolution, the proposed device is equipped with a crystal oscillator, a balanced mixer with a tunable local oscillator, a frequency detector and an input mixer, to the other input of which the delay output is connected and the output of the named mixer is loaded a series-connected amplifier, a balanced mixer, a frequency detector and a DC voltmeter, and the output of the tunable the thermo is connected to the input of a balanced mixer, and the output of the crystal oscillator is connected to the input of the frequency detector.

In the drawing and the block diagram of the proposed device.

It contains mixer /, delay line 2, amplifier 3, balanced mixer 4 tunable local oscillator 5, frequency1) 1st detector 6, crystal oscillator 7, voltmeter S of constant current. To the output of the device: l) an oscilloscope 9 is connected to visually observe the envelope curve of the frequency deviation.

The device works as follows.

The frequency-modulated signal under study is fed to the mixer / input, and the delay line 2 is connected to the second mixer input. At the mixer output, as a result of the beating of the direct signal f ,,, n and delayed delay in delay 2, signal is extracted from the signal the difference frequency f rzn - / pr - / md, which is amplified by amplifier 3. The amplified signal of the difference frequency (ra, n and the signal of the tunable local oscillator 5 / got arrive at the balanced smsptel /. Formed signal

intermediate frequency / prom / 1st - / diff

arrives at the frequency detector 6, on the load of which an ogbahupp frequency module of the wired signal is allocated. By varying the frequency of the heterodyne, a zero voltage is obtained at the output of the device, measured by a voltmeter 8 having a scale with a zero and a middle. In this case, the rate of change of frequency will be equal to

7pr.,

Mr) M

ibcp - For visual observation of the modular characteristic of the FM signal to the output of the device, an oscilloscope 9 is connected with a constant current input, on the screen of which there will be a curve of) M. metrn relative to the zero linnn of the oscillograph. By varying the frequency of the local oscillator, you can combine any point of the modulation characteristic with a zero oscilloscope and determine the rate of change and hence the nonlinearity at any point of the modulus of the local oscillator using the formula D5 ::.: | 00 56. Jcp To reduce the measurement error, the frequency detector is calibrated using a quartz oscillator 7.

Object of the Invention A device for measuring the frequency deviation rate, containing an input delay delay amplifier and voltmeter of direct current, characterized in that, in order to measure the frequency deviation rate in any part of the frequency deviation and the increase in resolvability, it is equipped with a quartz oscillator, balanced mixer with the heterodyne tuned, the frequency detector and the input mixer, to the other input of which the output of the delay line is connected, and the output of the named SL: satellite is loaded in series with A single amplifier, balanced mixer, frequency detector, and DC voltmeter, the output of a tunable local oscillator is connected to the input of a balanced mixer, and the output of a crystal oscillator is connected to the input of a frequency detector.