JPS6050751A - Measuring and checking device of circuit substrate - Google Patents

Abstract

PURPOSE:To improve the space efficiency and the control workability and at the same time to solve the problems including the tape deterioration, etc. in order to improve the control accuracy, by incorporating a signal generating circuit, an FM demodulator, a wave detecting circuit, a frequency counter, a frequency converter, a display device, etc. into a single housing. CONSTITUTION:The FM signal supplied to an input terminal 54 is equal to a frequency multiplex signal containing the right and left channel FM signals obtained in a no- modulation mode. This multiples signal is supplied to land pass filters 56L and 56R respectively through a buffer amplifier 55. Then the FM signal is branched into three parts by distributors 57L and 57R and supplied to FM demodulators 61L and 61R, mean value wave detecting circuits 62L and 62R and contacts L and R of a switch 58, respectively. The frequencies are counted first by a frequency counter 59 and this count value is displayed digitally to a frequency display device 60. Then an FM-demodulated sine wave of 1kHz is taken out of demodulators 61L and 61R of a PLL wave detection system and supplied to a modulation degree display device 63. Thus the measurement/ check and control are possible for the FM modulation degree. Furthermore various types of measurements are possible for a reproducing circuit with no use of the reproduced signal of a magnetic tape when a measurement signal is supplied to the reproducing circuit.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a measurement and inspection device for circuit boards, and in particular to a circuit that generates a frequency-modulated audio signal and supplies it to a recording head, and a circuit that generates a frequency-modulated audio signal and supplies it to a recording head, and a circuit that generates a frequency-modulated audio signal and supplies it to a recording head. The frequency modulated audio signal is F
This invention relates to a device that measures, inspects, and adjusts a circuit board on which a circuit that demodulates and outputs M is mounted.

BACKGROUND ART The present applicant has previously disclosed in Japanese Patent Application No. 57-210211, etc., a frequency modulated audio signal (FM audio signal) using a dedicated rotary head provided separately from a rotary head for recording and reproducing video signals.
We proposed a method in which an audio track is formed and recorded at the same position as a video track on a magnetic tape, and this is then played back.

According to this proposed method, since the FM audio signal is recorded by a dedicated rotating head, the carrier is more Mutual interference caused by beats between frequencies can be greatly reduced, and moiré on the playback screen can be almost eliminated. High-quality audio recording, again! 1, etc. (a
The right features are included.

This proposed method was applied to the magnetic recording re-capture head (VTR).
) has the above [N1? “′.

A circuit board equipped with voice signal recording and reproducing circuits will be incorporated. This circuit board did not exist in conventional helical scan type VTRs, so this circuit book contains 81 measurements of each circuit on each board.

Since there is no adjustment device (1), it is considered to use a measurement and inspection device with a schematic configuration as shown in Figure 1, for example, to measure and adjust each circuit on this circuit board. It will be done.

In FIG. 1, a circuit board 1 includes an audio signal recording circuit consisting of a frequency modulator (FM modulator) for converting an input audio signal station into an FM signal, a 1-novel compression circuit for noise reduction, etc., and a reproduction FM audio It is equipped with an audio signal reproduction circuit consisting of an FM demodulator that modulates the signal to FM41, a dropout compensation circuit, a de-emphasis circuit, and a level expansion circuit for noise reduction. It is.

The measurement inspection items for the audio signal recording circuit of the circuit board 1-1- include the carrier frequency of the FM audio signal, the FM modulation degree, the FM recording level, etc., and the network side inspection items for the audio signal reproducing circuit include: These include audio signal output level, lever 1 noise, and S/N.

First, to explain the measurement inspection of the audio signal recording circuit, the input of the recorded audio signal is stopped and the frequency at the output end of the FM modulator, that is, the FM key gear frequency when no modulation is performed, is measured by the frequency counter 3 shown in FIG. j: Measured at a predetermined frequency (for example, 3.1M I-I for left channel 17)
Z and 1.7 MHz for the right channel) and adjust it to a predetermined frequency. Next, at the reference level and in the audio band, for example, a 1kl-1z sine wave is
The oscillator 4 shown in the figure generates and outputs this sine wave at V
The signal is supplied to the audio signal recording circuit on the circuit board 1 through the audio signal input terminal of the TR 2, where it is converted into an FM signal, and then supplied to the FM modulation degree measuring device 5. FM modulation degree measuring device 5
FM demodulates the input FM signal to obtain a demodulated 6-wave sine wave, then imitates the frequency of the DC 1 novel and converts it to FM.
The frequency deviation of the signal is measured, and the FM modulation depth is measured from this and the modulation frequency.
? r', that is, the "M recording level" is measured, and if it is not a predetermined value, the level is adjusted to a variable resistor on the head input side so that it becomes a predetermined value.

Next, I will explain the four-measure inspection of the audio signal reproduction circuit.
Predetermined gt 11! [First recording in which M signal 7J is recorded for both left and right channels] is frequency modulated with a sine wave of a constant frequency at two levels, and only the FM signal of one Bouyannel is recorded, and the other channel is is the second recording in which there is no signal] - The measurement magnetic tape 7, on which the rack and the non-recorded portions in which there is no signal are formed in both channels, is loaded into the VTR 2 and played back.

Thereby, the signals reproduced from the magnetic tape 7 are reproduced by the audio signal reproduction circuit on the circuit board 1 and then supplied to the measuring instrument.

In this case, the F reproduced from the first recording 1-rack is
By measuring the demodulated signal level of the M signal, the output level can be measured, and when the second recording track is reproduced, the demodulated output D%j of the other channel, which has no signal, can be measured.
, (f) level (leakage signal level from one channel), etc. to measure separation. In addition, by measuring the noise level when playing back the part where there is no signal on both channels, the S/N
Can be checked.

[Problems to be Solved by the Invention] To begin with, the above-mentioned measurement and inspection device uses a frequency counter 34, an oscillator 4. FM modulation degree measuring device 5, oscilloscope 6, etc. must be prepared, which is expensive.
In addition, the work is complicated as many of these devices must be used depending on the measurement and inspection item, and the work becomes even more complicated especially when there are two audio channels.
Furthermore, there was a problem of poor space efficiency. Furthermore, the measuring magnetic tape 7 must be used for various measurement tests of the audio signal reproducing circuit, but since the magnetic tape 7 comes into contact with the head once every time the audio signal is reproduced, durability and reliability cannot be improved. There was a problem with that.

Therefore, the present invention provides a signal generation circuit and an FM demodulator.

A circuit board that solves the above problems by incorporating the detection circuit 1 frequency counter, frequency modulator 1 display, etc. in a negative housing, and also generates and outputs a signal corresponding to the reproduced FM signal. The purpose of this invention is to provide a measurement and inspection device.

Means for Solving the Problems The present invention provides an M measurement inspection device for a circuit board, which is equipped with a recording circuit that outputs a frequency modulated wave signal and a recording signal at the same time as a recording signal, and a reproducing circuit having an FM demodulation circuit. an FM demodulator for FM demodulating a first frequency modulated wave signal obtained through the recording circuit with a reference 1-novel signal corresponding to the input signal, and an output signal level of the FM demodulator; a first display for indicating the degree of modulation; a detection circuit for detecting the first frequency-modulated wave signal; 2 display and the corresponding L↓
a signal generating circuit that generates a signal whose level can be varied, such as a frequency counter that subsides the frequency of the first frequency-modulated wave signal when the transmission of the quasi-level signal to the recording circuit is stopped; and the signal generating circuit. a frequency modulator that outputs a second frequency-modulated wave signal obtained by frequency-modulating a carrier frequency that is the same as the predetermined frequency to the reproducing circuit, and is housed in a housing. The circuit board is configured to perform a four-measure inspection of the circuit board using each of the circuits described above, and one embodiment thereof will be described below with reference to FIGS. 2 to 5.

Embodiment Before explaining one embodiment of the apparatus of the present invention, a circuit mounted on a circuit board to be measured and inspected by the apparatus of the present invention will be explained. FIG. 2 shows an example of a recording circuit on a circuit board. Figure 3 shows a circuit diagram of an example of a reproducing circuit on a circuit board. In both figures, each circuit of the left channel audio signal transmission line is marked with a subscript R to the number 8, and each circuit of the right 10-channel audio signal transmission line is marked with a subscript R to the number 8.
It is attached. In FIG. 2, input terminals 91-. 9R
The left image was received and demodulated by Juna.

The right channel audio signal is input to input terminals 101 and 11.
1-. 10R and 11n receive left and right channel audio signals from microphones and other audio equipment, and input terminals 12+- and 12R receive left and right channel audio signals from a television camera.
Right channel audio signal is incoming. The left and right channel audio signals are passed through switching circuits 13L, 13R and variable resistors 14+-, 14R, respectively, to GG circuits 151-.
15R.

The ΔGC circuits 15L and 15R are configured to be controlled by a switch 16 (J: reoff/on), and when on, limit the peak level of the input audio signal to a constant value. The output audio signals of the ΔGC circuits 15L and 15R are subjected to level compression for noise reduction, encoders 1F L, 1F R, and amplifier 18L.
, 18R, low-pass filter 191-. 19R, ΔGC circuit 151-.

Limiter 2OL, 20R1 and variable resistor 21L for limiting the amplitude of an excessive level when 15R is off.

21R1 and a frequency modulator (FM modulator) 22L through a pre-emphasis circuit (not shown).

22R is supplied.

The 1M modulator 22L is set to 1171 by the variable resistor 23L.
7 frequency is set to 1.3M+-17, for example.
Frequency modulation is performed on 1.3MH7 using the left channel audio signal, and a frequency modulated audio signal (FM audio signal) is output. This left channel FM audio signal is supplied to the preamplifier 26 through a low-pass filter 24L and a recording level adjustment variable resistor 251-, respectively.

In use, the FM modulator 22R has a carrier frequency set to, for example, 1.7 MHz by a variable resistor B 23 R, and outputs a right channel FM audio signal.

This right channel FM audio signal is filtered through a low-pass filter 24R.
and a recording level adjustment variable resistor 25R, respectively, to the preamplifier 26, where it is frequency division multiplexed with the left channel FM audio signal, and then outputted through output terminals 27-1 and 27-2 into two audio signals for recording. are respectively supplied to rotating heads (not shown).

Next, to explain one reproducing circuit shown in FIG.
The respective reproduction signals (frequency division multiplexed signal of the left channel FM combined voice signal and the right channel audio signal) from the audio signal rotary head 71 (not shown) are alternately input to the input terminal 28- for each field period. 1.28-2 and is further supplied to the amplifier 30 through the preamplifier 29. The reproduced signal taken out from the amplifier 30 is passed through a bandpass filter 31L.
and 31R, where the left channel FM audio signal and the right channel 17 FM audio signal are frequency-selected and extracted. The reproduced left channel FM audio signal is passed through the amplifier 32L to the limiter 33L and the dropper [
- Supplied to the detection circuit 34L, respectively. Limiter 33L
The output reproduced FM audio signal is passed through a phase comparator 35, a voltage controlled oscillator (VCO) 36L and a buffer amplifier 371-
The well-known phase-locked loop (P L
After being FM-demodulated by the FM demodulator located at L) 13-, the signal is supplied to a sample-and-hold circuit 411- through a low-pass filter 39L with a cutoff frequency of about 60kHz and an amplifier 40. Similarly, the right channel FM audio signal taken out from the bandpass filter 31R and reproduced is transmitted to the amplifier 32R.
The signal is supplied to the dropout detection circuit 34R through the filter, and after being FM demodulated by an FTL modulator using P I-L, the signal is supplied to the sample hold circuit 41R. The sample and hold circuits 41L and 41R are based on the detection signals from the dropout detection circuits 34+ and 34R, and during the dropout occurrence period, the reproduction signal level (
This circuit holds the terminal voltages of the hold capacitors 42L and 42R, and allows the input signal to pass through as is during a period when no dropout occurs.

The output reproduction audio signals of the sample and hold circuits 41L and 4.1R are output from amplifiers 44L and 44R, de-emphasis circuits 45L and 45Rz variable resistor 46L.

46R1 level decompression and decoder 47L, 47R.

14- Output 9 through amplifier/I8+-, 48R respectively
It is output to ゜49R. In this way, output *;1:
The playback left channel audio signal that has been FM demodulated and subjected to dropout compensation and noise reduction processing is output to the output terminal 49L, and the playback right channel audio signal that has been subjected to similar signal processing is output to the output terminal 49R. Shosei Shinkyu is taken out. Note that the broken line 501. , 50 The circuit part surrounded by r< is T
It can be converted into a C (integrated circuit).

Next, an embodiment of the present invention apparatus for measuring and inspecting each part of the recording circuit and reproduction circuit on the circuit board will be described. Fig. 4 (Δ>, (1B) is a block system diagram of an embodiment of the device of the present invention, and Fig. 5 is an external front view of an embodiment of the device of the present invention. In both figures, the same components are The same reference numerals refer to the same numbers.This embodiment is a device that tests the network side of the recording circuit, and supplies a measurement test signal to one circuit.
The entire circuit shown in FIG. 4 (Δ) and (r3) is housed in a J'12 body 70 shown in FIG. d3, it 1llll+ inspection of the reproduction circuit is performed in the same manner as explained in FIG. 14. First, to explain the measurement and inspection operation of the recording circuit, press the recording button indicated by RFC in FIG.
Enter recording adjustment mode. When measuring and inspecting the FM carrier frequency, the button 71L or 71R in FIG. 5 is pressed.

When button 71+- is pressed, switch 5 of Fig. 4 (A>
8 is connected to the contact side, and when the button 71R is pressed, the switch 58 is connected to the contact R side. Also, the input terminals 9L to 12L shown in FIG. 2 of the Iζ recording circuit.

No signal is supplied to 9R to 12R. Therefore, the FM signal that enters the input terminal 54 in FIG. 4 (△) via the output terminal 27-1 or 27-2 is frequency division multiplexed between the left channel FM signal and the right channel FM signal when no modulation is performed. This multiplexed signal is supplied to bandpass filters 561- and 56R through buffer amplifier 55, respectively.

The passband of the bandpass filter 56L is selected to be a band necessary to pass the left channel "M audio signal (for example, 1.3MH1±150kHz2), and the passband of the bandpass filter 56L is
6R has a passband of the right channel FM signal (for example, 1
．． 7M+-12±150kHz) is selected as the band necessary to pass it. Therefore, bandpass filter 501
The /F channel FM signal at the time of unnecessary L1!1 is taken out from -, and the right channel F M I ;'i at the time of no modulation is taken out from the bandpass filter 56R. Bandpass filter 561-. 56RC1; The extracted FM signal is branched into three by dividers 57+-, 57R and sent to FM demodulators 61c, 61r<, and average value detection circuit 621.
−． 62R, and the contact R of the switch 58. Here, assuming that the button 71L is pressed, the output FM signal of the distributor 57 The value is displayed digitally.

This frequency value is 1.3M+-12 because it is the unmodulated carrier frequency of the left channel M signal. Adjust the variable resistor 23 +- in the figure so that the frequency is within 1.3M+-17±10kl-IZ.

Similarly, by pressing the button 71R, the unmodulated carrier frequency of the right channel FM signal taken out from the distributor 57R will be measured and displayed on the frequency table 17-indicator 60! I can do that. This frequency value is 1.7M117±10k
When the frequency is outside l-1z, the resistance value of the variable resistor 23R in Fig. 2 is varied to obtain 1.7M t-1l-+=1.
Adjust so that the frequency is within 0kl-1z. In this way, by simply pressing the buttons 71L and 71R, it is possible to measure and inspect the unmodulated carrier frequencies of the FM audio signals of the left and right channels to be recorded, and furthermore, the adjustment becomes easy.

Next, when measuring and inspecting the FM modulation degree and FM signal recording level, a modulation signal of 1 kHz, for example, is sent to the recording circuit on the board.
A z sine wave of -20 dB is supplied and input to the FM low output input terminal 54 of the board. As a result, Pl- in FIG. 4(A)
1-Detection method FM demodulators 61L and 61R output F.
The M-demodulated 1kl-12 sine waves are taken out and supplied to the modulation index display 63, respectively. As shown in FIG. 5, the modulation degree indicator 63 has two pointers 72L and 72R, each of which has a completely different color. Convert the peak level to the shift frequency (lt 1st place k) - lz) and indicate ↑172
At the same time, the DC peak-to-peak level of the demodulated signal of the right channel from FMtLJ[61R is similarly converted into a shift frequency and displayed by finger 1t72R. The above reference level is selected to a value that allows an operational deviation (for example, ±50kHz) of 1M signal (for example, ±50kHz), so the display 63 should be monitored so that such an operational deviation (FM modulation degree) can be obtained. Variable resistor 2 in Figure 2
1.

The resistance value of 21R is varied. In this way, measurement, inspection and adjustment of the FM modulation degree can be performed.

On the other hand, the detection signals of the left and right channel FM signals extracted by the average value detection circuits 62L and 62R are supplied to the recording level indicator 64. The recording level indicator 64 is the fifth
As shown in the figure, two fingers t173L with different colors from each other
and 73R respectively, and can display up to a maximum level of 50111Vp-p with the finger 73L, and can display a maximum level of 200mVp-p with the pointer 73n. Value detection circuit 6
The 4M configuration is such that the output detected voltage of 2 is displayed by the pointer 731-, and the output detected voltage of the average value detection circuit 62R is displayed by the pointer 73R. Therefore, the pointer 731- of the display 64 measures and displays the recording level of the left channel FM signal, and the finger i+ 73R measures and displays the recording level of the right channel FM signal.
The recording level of the M signal is measured and displayed. Pointer 73L, 7
While watching 3R, the predetermined recording level will be displayed.
Variable resistor 25L in FIG.

The resistance value of 25R is variable. As is well known, the level characteristics of tape recording and playback decrease at high frequencies.
To compensate for this, the right channel FM signal, which has a higher frequency, is recorded at a higher recording level than the left channel FM signal.

Next, to explain the operation of supplying the measurement signal to the reproducing circuit, first press the button indicated by PB in FIG. 5 to set the measurement signal output mode. This measurement signal is generated based on the output signal of the signal generation circuit 65 shown in FIG. 4(B). The signal generating circuit 65 generates, for example, 20 Hz using the knob 7/I in FIG.

1oo1-1z, 4001-17. 1 kl-1z
, 5 kl-1z, 10kHz, 15kHz
and 201 (8 types of same wave numbers of 11z) 5 - frequencies are generated and output. From this signal generation circuit 65
The frequency signal is fed to a variable attenuator 66 where it can be adjusted in steps of 1 or 10 in the range from 0 to -60,1R.
The amount of attenuation is varied by the CE module. This attenuation amount is 1
To decrease the value in dB steps, press button 75 in Figure 5.
1 (Press button 76 to increase the amount of attenuation (to obtain a larger amount of attenuation) in E steps, and press buttons 77 and 78 to increase the amount of attenuation in steps of 10. Buttons 75 to 78 The number of times you press is the number of steps.

The signal generating circuit 65 and the variable attenuator 66 constitute a signal generating circuit, and the output signal frequency and attenuation amount are digitally displayed on the respective display devices 81 and 82 in FIG. 5. The single frequency signal in the audio band taken out from the variable attenuator 66 is supplied to a frequency modulator (voltage-frequency converter) 67 and 67R, respectively, and converted into an FM signal. Note that, for example, when the attenuation amount is -20'', the deviation of the FM signal 21- is ±50 kl-Iz. The frequency modulator 67L modulates the frequency of the carrier frequency 1.3 MH2 with the input signal and supplies the obtained FM signal to the mixing circuit 69 through the normally closed switch 68L as a left channel FM signal. Also, the frequency modulator 67R is a frequency modulator 67L.
Similarly, the internally adjusted distortion rate is 0.05% or less at 1 kHz, but the FM obtained by frequency modulating the carrier frequency of 1.7 MHz with the input signal (with the i signal as the right channel FM signal, the normally closed The signal is supplied to the mixing circuit 69 through the switch 68R.As a result, from the mixing circuit 69, a signal obtained by frequency division multiplexing the left channel FM signal and the right channel FM signal, respectively, is transmitted to the first channel on the circuit board as a reproduced FM signal. Bandpass filter 31 + of the regeneration circuit shown in Fig. 3
- and to the input side of 31R.

As a result, without using the magnetic tape playback signal,
Various measurements of the reproducing circuit can be performed. In addition,
When checking the separation, press the button 79 shown in Figure 5.
Or press 80 and set switch 68 or 68 [≧A) in Figure 4 22-(B) to mix the FM signal of one channel of the 2 channel [M blind] with no signal and 1) signal. output from the circuit 69, and when checking the S/N, press the buttons 79 and 80 together to make the output "M signal" of the mixing circuit 69 "no signal".
When the switch 83 shown in FIG. 5 is set to the rMIXJ side, the output signal g of the mixing circuit 69 shown in FIG. 4 (13) is output to the outside, and when the switch 83 shown in FIG. The Ryokawa power signal of 68R is separately output to the left and right f channel FM signal output terminals.

effect As mentioned above, according to the present invention, there is provided a signal generation circuit.

Since the FM demodulator, detection circuit 1 frequency counter, frequency converter 3 display, etc. are built into the - housing, space efficiency can be improved compared to when separate measuring devices are prepared. In addition, it can be constructed at low cost, and the desired measurement and inspection items can be measured simply by operating switches and buttons installed on the housing without changing the connection to the circuit board, greatly improving measurement work efficiency. In addition to improving adjustment work efficiency,
In addition, since the signal equivalent to the reproduced FM signal is generated by the signal generation circuit, problems such as deterioration peculiar to tape can be solved and the adjustment accuracy can be greatly improved compared to when using the reproduced signal from magnetic tape. In addition, the detection circuit is an average value detection circuit, so the circuit configuration is simple, and the frequency counter can be used regardless of the number of input signal channels. This has the advantage that the circuit configuration can be further simplified since only one is required.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of a configuration that can be used as a circuit board measurement and inspection device, etc. Fig. 2 is a circuit system diagram showing an example of a recording circuit of a circuit board that can be measured with the device of the present invention; The figure is a circuit system diagram showing an example of a reproducing circuit on a circuit board that can be measured by the device of the present invention. FIG. 5 is a front view showing the appearance of an embodiment of the device of the present invention. 1... Circuit board, 3... Frequency counter, 7...
Magnetic tape for measurement, 91-12L... Left channel audio signal input terminal, 9R-12R... Right channel A7 audio signal input terminal, 17L, 17R... Level compression and encoder, 22L, 22R... Frequency modulator (FM
Modulator), 25L, 25R... Variable resistor for adjusting recording level, 28-1.28-2... Reproduction FM audio signal input terminal, 34L, 34R... Dropout detection circuit, 47L, 47R. ...Level expansion and decoder, 50
L, 50R...IC, 54...FM signal input terminal,
56L, 56R... Bandpass filter, 58... Switch, 59... Frequency counter, 60... Frequency display, 61L, 61R... FM demodulator, 62. 62R... Average value detection circuit, 63... Modulation degree indicator, 64... Recording level indicator, 65... Signal generation circuit, 66... Variable attenuator, 671-. 67R・
...Frequency modulator, 69...Mixing circuit, 72m, 72
R. 73L, 73R...Finger 11°25-

Claims (4)

[Claims] (1) A recording circuit that generates and outputs a frequency modulated wave signal obtained by frequency modulating a predetermined carrier frequency with an input signal as a recording signal, FM demodulates the frequency modulated wave signal input as a playback signal. A measurement and inspection device for a circuit board is equipped with a circuit for outputting signals, and the device is configured to perform FMM demodulation of a first frequency modulated wave signal obtained by passing a signal at a base t1 (level) corresponding to the input signal g through the recording circuit. an M demodulator, an output signal level of the FM demodulator, a first indicator for indicating the M modulation degree, a detection circuit for detecting the first frequency modulated wave signal, and a detection circuit for detecting the first frequency modulated wave signal; Circuit output signal 1 novel j
A second display for displaying one novel, a frequency counter that measures the frequency of the first frequency-modulated wave signal that occurs when the signal at the reference level stops being sent to the recording circuit; a signal generating circuit that generates a signal that can vary the frequency, and a second frequency modulated wave signal obtained by frequency modulating a carrier frequency that is the same as the predetermined frequency with the output signal of the signal generating circuit, to the reproducing circuit. 1. A measurement and inspection device for a circuit board, characterized in that the circuit board is measured and inspected by each of the circuits described above, which includes a frequency modulator that outputs an output, and which is housed in a negative housing. (2) The signal generation circuit attenuates a signal with a frequency of − arbitrarily selected from a plurality of signals having different frequencies by an attenuation amount arbitrarily selected from among a plurality of preset attenuation amounts. A four-measurement inspection device for a circuit board according to claim 1, which is a circuit for outputting. (3) The circuit board outputs frequency modulated wave signals of multiple channels having different carrier frequencies as recording signals, and is equipped with a circuit for obtaining FM demodulated signals of the multiple channels, and includes a circuit for obtaining FM demodulated signals of the multiple channels, and includes an FM demodulator and a detector. A plurality of circuits and frequency modulators are provided in parallel according to the number of channels, and the first and second indicators are arranged in parallel according to the number of channels A7, respectively, and a plurality of RQ l-J are provided in accordance with the number of channels. A measurement and inspection device for a circuit board according to claim 1]1''i. (4) The detection circuit is an average value detection circuit, and the FM demodulator is a peak detection type circuit using a f:[-'s locked loop.
A sub-side inspection device for a circuit board as described in 2. 6) The circuit board records frequency modulated waves 18 of multiple channels with different carrier frequencies as recording signals 11.
When outputting one signal, the FM demodulated signals of the plurality of channels are
The frequency counter is equipped with a switch at the input stage that selects and outputs only the frequency modulated wave signal 8 of any one channel of the plural channels of frequency modulated wave signals. A circuit board π1 measurement inspection device according to claim 1 or 3 of the 171st edition, characterized in that: