The reason for the creation of this device was a considerable number of accumulated quartz resonators, both purchased and soldered from different boards, and many did not have any designations. Traveling through the endless expanses of the Internet and trying to collect and launch various ones, it was decided to come up with something of my own. After many experiments with different generators, both on different digital logics and on transistors, I chose the 74HC4060, though it was also not possible to eliminate self-oscillations, but as it turned out, this does not interfere with the operation of the device.
Quartz meter circuit
The device is based on two CD74HC4060 generators (the 74HC4060 was not in the store, but judging by the datasheet they are even “cooler”), one operates at a low frequency, the second at a high one. The lowest frequencies I had were watch quartz, and the highest frequency was non-harmonic quartz at 30 MHz. Due to their tendency to self-excitation, it was decided to switch generators simply by switching the supply voltage, as indicated by the corresponding LEDs. After the generators, I installed a repeater on the logic. Perhaps instead of resistors R6 and R7 it is better to install capacitors (I did not check it myself).
As it turned out, not only quartz is launched in the device, but also all sorts of filters with two or more legs, which were successfully connected to the appropriate connectors. One "two-legged" ceramic-like capacitor started at 4 MHz, which was then successfully used instead of a quartz resonator.
The pictures show that two types of connectors are used to check radio components. The first one is made from parts of the panels - for output parts, and the second one is a board fragment glued and soldered to the tracks through the corresponding holes - for SMD quartz resonators. To display information, a simplified frequency meter was used on the PIC16F628 or PIC16F628A microcontroller, which automatically switches the measurement limit, that is, the frequency on the indicator will be either in kHz or in MHz.
About device details
Part of the board is assembled on lead parts, and part on SMD. The board is designed for the Winstar single-line LCD indicator WH1601A (this is the one with the contacts on the top left), contacts 15 and 16, which are used for illumination, are not separated, but whoever needs it can add tracks and details for himself. I didn’t dim the backlight because I used an indicator without backlight from some phone on the same controller, but first there was Winstar. In addition to WH1601A, you can use WH1602B - two-line, but the second line will not be used. Instead of a transistor, that in the circuit you can apply any of the same conductivity, preferably with a larger h21. The board has two power inputs, one from mini USB, the other through the bridge and 7805. There is also a place for a stabilizer in another case.
Instrument setup
When setting with the S1 button, turn on the low-frequency mode (the VD1 LED will light up) and by plugging a 32768 Hz quartz resonator into the appropriate connector (preferably from the computer motherboard) with a tuning capacitor C11, set the frequency of 32768 Hz on the indicator. Resistor R8 sets the maximum sensitivity. All files - boards, firmware, datasheets for the radio elements used and more, download in the archive. Project author - nefedot.
Discuss the article DEVICE FOR CHECKING THE FREQUENCY OF QUARTZ
Fluctuations are given one of the most important roles in the modern world. So, there is even the so-called string theory, which claims that everything around us is just waves. But there are other options for using this knowledge, and one of them is a quartz resonator. It just so happens that any technique periodically fails, and they are no exception. How to make sure that after a negative incident it still works as it should?
Let's say a word about the quartz resonator
A quartz resonator is an analog of an oscillatory circuit based on inductance and capacitance. But there is a difference between them in favor of the first. As you know, to characterize the oscillatory circuit, the concept of quality factor is used. In a resonator based on quartz, it reaches very high values - in the range of 10 5 -10 7 . In addition, it is more efficient for the entire circuit when the temperature changes, which affects the longer life of parts such as capacitors. The designation of quartz resonators in the diagram is carried out in the form of a vertically located rectangle, which is “clamped” by plates on both sides. Outwardly, in the drawings, they resemble a hybrid of a capacitor and a resistor.
How does a quartz resonator work?
A plate, ring or bar is cut out of a quartz crystal. At least two electrodes are applied to it, which are conductive strips. The plate is fixed and has its own resonant frequency of mechanical vibrations. When voltage is applied to the electrodes, due to the piezoelectric effect, compression, shearing or bending occurs (depending on how the quartz was cut). The oscillating crystal in such cases does work like an inductor. If the frequency of the voltage that is supplied is equal to or very close to its own values, then less energy is required with significant differences to maintain operation. Now we can move on to highlighting the main problem, which, in fact, is why this article is being written about a quartz resonator. How to check its performance? 3 methods were selected, which will be discussed.
Method number 1
Here, the KT368 transistor plays the role of a generator. Its frequency is determined by a quartz resonator. When power is supplied, the generator starts to work. It creates impulses that are equal to the frequency of its main resonance. Their sequence passes through the capacitor, which is designated as C3 (100r). It filters the DC component, and then the pulse itself is transmitted to an analog frequency meter, which is built on two D9B diodes and such passive elements: capacitor C4 (1n), resistor R3 (100k) and a microammeter. All other elements serve for the stability of the circuit and so that nothing burns out. Depending on the set frequency, the voltage that is on the capacitor C4 can change. This is a fairly approximate method and its advantage is ease. And, accordingly, the higher the voltage, the higher the frequency of the resonator. But there are certain limitations: you should try it on this circuit only if it is in the approximate range of three to ten MHz. Checking quartz resonators that goes beyond these values \u200b\u200busually does not fall under amateur radio electronics, but a drawing will be considered below, which has a range of 1-10 MHz.
Method number 2
To increase the accuracy, you can connect a frequency meter or an oscilloscope to the generator output. Then it will be possible to calculate the desired indicator using the Lissajous figures. But keep in mind that in such cases, the quartz is excited, both at the harmonics and at the fundamental frequency, which, in turn, can give a significant deviation. Look at the given diagrams (this and the previous one). As you can see, there are different ways to find the frequency, and here you have to experiment. The main thing is to follow safety precautions.
Checking two quartz resonators at once
This circuit will allow you to determine whether two quartz resistors that operate within one to ten MHz are operational. Also, thanks to it, you can recognize the shock signals that go between frequencies. Therefore, you can not only determine the performance, but also select quartz resistors that are most suitable for each other in terms of their performance. The circuit is implemented with two master oscillators. The first of them works with a ZQ1 quartz resonator and is implemented on a KT315B transistor. To check the performance, the output voltage must be greater than 1.2 V, and you should press the SB1 button. The specified indicator corresponds to a high level signal and a logical unit. Depending on the quartz resonator, the required value for testing can be increased (you can increase the voltage for each test by 0.1A-0.2V to that recommended in the official instructions for using the mechanism). In this case, the output DD1.2 will have 1, and DD1.3 - 0. Also, reporting the operation of the crystal oscillator, the HL1 LED will light up. The second mechanism works similarly and will be reported by HL2. If they are started at the same time, the HL4 LED will still be on.
When the frequencies of two generators are compared, their output signals from DD1.2 and DD1.5 are sent to DD2.1 DD2.2. At the outputs of the second inverters, the circuit receives a pulse-width modulated signal in order to then compare the performance. You can see this visually by blinking the HL4 LED. To improve accuracy, add a frequency counter or oscilloscope. If the real indicators differ by kilohertz, then to determine a higher-frequency quartz, press the SB2 button. Then the first resonator will decrease its values, and the tone of the beats of the light signals will be less. Then we can confidently say that ZQ1 is more high-frequency than ZQ2.
Features of checks
When checking always:
- Read the instructions that the quartz resonator has;
- Stick to safety precautions.
Possible causes of failure
There are quite a few ways to disable your quartz resonator. Some of the most popular are worth checking out in order to avoid any problems in the future:
- Falls from a height. The most popular reason. Remember: it is always necessary to keep the workplace in perfect order and monitor your actions.
- The presence of a constant voltage. In general, quartz resonators are not afraid of it. But there were precedents. To test the performance, turn on a 1000 mF capacitor in series - this step will return it to operation or avoid negative consequences.
- Signal amplitude too high. You can solve this problem in different ways:
- Take the generation frequency a little to the side so that it differs from the main indicator of the mechanical resonance of quartz. This is a more difficult option.
- Lower the number of volts that feed the generator itself. This is an easier option.
- Check if the quartz resonator is really out of order. So, the reason for the drop in activity may be flux or foreign particles (in this case, it is necessary to clean it thoroughly). It may also be that the insulation has been used too actively, and it has lost its properties. For a control check on this item, you can solder a “three-point” on KT315 and check with an axle (at the same time, activity can be compared).
Conclusion
The article discussed how to check the performance of such elements of electrical circuits as the frequency of a quartz resonator, as well as their property. Ways of establishing the necessary information were discussed, as well as possible reasons why they fail during operation. But to avoid negative consequences, always work with a clear head - and then the work of the quartz resonator will be less disturbing.
4 quartz resonator testers 
The correct functioning of a quartz crystal can be verified by including it in an oscillator or filter circuit. Figure 1 shows a diagram developed by C. Tavernier (France).
Since the frequencies of the crystals to be dealt with can cover a very wide range from 1 to 50 MHz, the circuit is a wide range oscillator. An aperiodic generator is assembled on transistor T1.
If the tested quartz is working, then a pseudo-sinusoidal signal will be present at the T1 emitter at the fundamental frequency of the crystal. This signal is rectified by diodes D2, D1, and when the voltage across the capacitor C4 reaches a value sufficient to open the transistor T2, the LED in the collector circuit T2 starts to glow. This indicates the health of the quartz. To determine the oscillation frequency, you can connect a frequency meter or an oscilloscope in parallel with resistor R2.
In Figure 2 - a sound tester from the heading "abroad" of the RADIO magazine No. 12, 1998.
The 4060 chip is a binary counter, which includes a generator. If you assemble this circuit, generation occurs at the fundamental frequency of the resonator. Then the microcircuit dividers lower the frequency to the sound one, which is heard in the low-impedance sound head. The prototype of the tester confidently worked with resonators from 1 to 27 MHz. In the latter case, the output frequency was about 6.6 kHz. The domestic analogue of 4060 is a microcircuit of the 1051ХЛ2 type. 
Figure 3 shows a tester that I whipped up 5-6 years ago. Similar schemes in the literature and the Internet are full. In this circuit, quartz 1 ... 30 MHz are wound up. According to the readings of the microammeter, it is possible to evaluate the activity of quartz.
It should be borne in mind that quartz with a frequency above 20 MHz is usually harmonic. Therefore, when testing quartz at 32 MHz, it “wound up” at its main frequency of 10.67 MHz, which was shown by the frequency meter.
As soldered, it is stored in a box, the board and the case make a bummer.
The wide range oscillator is of course versatile and, in most cases, useful. However, inactive quartz may not start in it. But do not rush to throw it away. In this case, you can correct the values of the capacitances C1 and C2, as recommended in [Radiohobby 1999 No. 3s22-23]. For the best excitation conditions, C1 should be approximately numerically equal to the wavelength in meters generated by quartz (on the first, fundamental harmonic). For example, if the quartz is at 1 MHz, then C1 \u003d 300 pF. For better self-excitation, C2 can be selected 1.5 ... 2 times less than the capacitance C1. For C3, the capacity is approximately equal to C2 (Fig. 4) 
The main feature of this frequency meter:
A highly stable TCXO (Thermo-Compensated Reference Oscillator) is adopted. The use of TCXO technology allows immediately, without preheating, to provide the declared frequency measurement accuracy.
Technical characteristics of the FC1100-M3 frequency counter:
| parameter | minimum | norm | maximum |
| Measuring frequency range | 1 Hz. | - | 1100 MHz. |
| Frequency readout resolution from 1 to 1100 MHz | - | 1 kHz. | - |
| Frequency readout resolution from 0 to 50 MHz | - | 1 Hz. | - |
| Input signal level for input "A" (from 1 to 1100 MHz). | 0.2 V.* | 5 W.** | |
| Input signal level for input "B" (0 to 50 MHz). | 0.6V | 5 V. | |
| Update period | - | 1 time/sec | - |
| Testing of quartz resonators | 1 MHz | - | 25 MHz |
| Supply voltage/current consumption (Mini-USB) | +5V./300mA | ||
| Frequency stability @19.2MHz, at temperature -20С...+80С | 2ppm(TCXO) |
Distinctive features of frequency meters of the FC1100 line in particular:
| Highly stable reference oscillator TCXO(stability is not worse than +/-2 ppm). | |
| Factory calibration. | |
| Independent simultaneous measurement of two frequencies (Input "A" and Input "B"). | |
| Input "B": Provides frequency measurement resolution of 1 Hz. | |
| Input "B" has a full-fledged analog input comparator threshold control (MAX999EUK), which makes it possible to measure, including signals noisy with harmonics, by adjusting the comparator threshold to a clean section of the periodic signal. | |
| Input "A" allows you to remotely measure the frequency of portable VHF radios at a distance of several meters, using a short antenna. | |
| Function of fast testing of quartz resonators from 1 to 25 MHz. | |
| Modern TFT color display with economical backlight. | |
| The manufacturer does not use unreliable electrolytic capacitors. Instead, modern high-quality SMD ceramic capacitors of significant capacities are used. | |
| Unified power supply via Mini-USB connector (+5v). Mini-USB power cord - supplied. | |
| The design of the frequency meter is optimized for integration into the flat front panel of any enclosure. Nylon insulating posts M3*8mm are supplied in the kit to provide a gap between the front panel and the printed circuit board of the frequency meter. | |
| The manufacturer guarantees that programmed aging technologies, which are widely used in modern technology, are not used. | |
| Made in Russia. Small batch production. Quality control at every stage of production. | |
| The best solder pastes, non-cleaning fluxes and solders are used in the production. | |
| Since November 22, 2018, the FC1100-M3 frequency counter has been on sale. Here are ALL its differences and advantages: | |
| Improved stability of the input comparator, its sensitivity, linearity. | |
| Updated firmware. The work of the circuit has been optimized. | |
| By popular demand, an SMA-BNC adapter has been added to the kit, allowing you to use numerous standard cables, including oscilloscope probes with BNC connectors. |
Dimensions of the printed circuit board of the FC1100-M3 device: 83mm * 46mm.
Display color TFT LCD with backlight (diagonal 1.44" = 3.65cm).
* Sensitivity according to DataSheet MB501L ("Input Signal Amplitude" parameter: -4.4dBm = 135 mV@50 Ohm respectively).
** The upper limit of the input signal is limited by the dissipation power of the B5819WS protective diodes (0.2W*2 pcs).
Back side of FC1100-M3 counter
Quartz frequency measurement mode in FC1100-M2 and FC1100-M3 frequency counters
Scheme of the comparator / shaper of the input signal 0 ... 50 MHz.
Scheme of the frequency divider of the input signal 1...1100 MHz.
Brief description of FC1100-M3 frequency counter:
The FC1100-M3 frequency meter has two separate frequency measurement channels.
Both channels of the FC1100-M3 operate independently of each other and can be used to measure two different frequencies at the same time.
In this case, both values of the measured frequency are simultaneously displayed on the display.
"Input A" - (Connector type SMA-FEMALE) Designed to measure relatively high-frequency signals, from 1 MHz to 1100 MHz. The lower sensitivity threshold of this input is slightly less than 0.2 V., and the upper threshold is limited at the level of 0.5 ... 0.6 V. by protective diodes connected in anti-parallel. It makes no sense to apply significant voltages to this input, because voltages above the opening threshold of protective diodes will be limited.
The applied diodes allow dissipating power no more than 200 mW, protecting the input of the MB501L divider chip. Do not connect this input directly to the output of high power transmitters (more than 100mW). To measure the frequency of signal sources with an amplitude of more than 5 V., or a significant power, use an external voltage divider (attenuator) or a low-capacity transition capacitor (units of picofarads) connected in series. If it is necessary to measure the frequency of the transmitter - usually a short piece of wire is sufficient as an antenna, included in the frequency meter connector, and located at a short distance from the transmitter antenna, or you can use a suitable rubber band antenna from portable radios connected to the SMA connector.
"Input B" - (Connector type SMA-FEMALE) Designed to measure relatively low-frequency signals, from 1 Hz to 50 MHz. The lower sensitivity threshold of this input is lower than that of "Input A", and is 0.6 V., and the upper threshold is limited by protective diodes at a level of 5 V.
If it is necessary to measure the frequency of signals with an amplitude of more than 5 V, use an external voltage divider (attenuator). This input uses a MAX999 high speed comparator.
The input signal is applied to the non-inverting input of the comparator, and resistor R42 is also connected here, increasing the hardware hysteresis of the MAX999 comparator to a level of 0.6 V. The bias voltage is applied to the inverting input of the MAX999 comparator, from the variable resistor R35, which sets the level of operation of the comparator. When measuring the frequency of noisy signals, it is necessary to turn the knob of the variable resistor R35 to achieve stable readings of the frequency meter. The highest sensitivity of the frequency meter is realized in the middle position of the knob of the variable resistor R35. Counter-clockwise rotation - reduces, and clockwise - increases the threshold voltage of the comparator, allowing you to shift the threshold of the comparator to a noise-free section of the measured signal.
The "Control" button switches between the "Input B" frequency measurement mode and the quartz resonator testing mode.
In the mode of testing quartz resonators, it is necessary to connect the tested quartz resonator with a frequency from 1 MHz to 25 MHz to the extreme contacts of the "Quartz Test" panel. The middle contact of this panel - you can not connect, it is connected to the "common" wire of the device.
Please note that in the test mode of quartz resonators, in the absence of the tested quartz in the panel, there is a constant generation at a relatively high frequency (from 35 to 50 MHz).
Also, it should be noted that when the investigated quartz resonator is connected, the generation frequency will be slightly higher than its typical frequency (within units of kilohertz). This is determined by the parallel mode of excitation of the quartz resonator.
The testing mode of quartz resonators can be successfully used to select the same quartz resonators for ladder multi-crystal quartz filters. In this case, the main criterion for the selection of quartz resonators is the closest possible generation frequency of the selected quartz.
Connectors used in the FC1100-M3 frequency counter:
Power Supply for Frequency Counter FC1100-M3:
The FC1100-M3 frequency meter is equipped with a standard Mini-USB connector with a supply voltage of +5.0 Volts.
Current Consumption (300mA max) - Provides compatibility with most USB voltage power supplies.
The kit includes a "Mini-USB" "USB A" cable, which allows you to power the frequency meter from any device that has such a connector (PC, Notebook, USB-HUB, USB Power Supply, USB Wall Charger) and so on.
For autonomous power supply of the FC1100-M3 Frequency Meter, the widely used "Power Bank" batteries with built-in Lithium-Polymer batteries, which are usually used to power equipment with USB connectors, are optimally suited. In this case, in addition to obvious convenience, as a bonus, you get galvanic isolation from the network and / or power supply, which is important.
Not available
To report
on arrival at the warehouse
To favoritesA set of components for assembling a frequency meter with the function of a quartz resonator tester.
Simple and inexpensive, developed on the basis of a PIC microcontroller with the ability to take into account the frequency shift of superheterodyne receivers during measurements with a five-digit LED indicator, convenient and intuitive.
Functions
- The display resolution is automatically switched to provide maximum reading accuracy with a 5-digit display.
Also, the duration of the measurement (gate time) is automatically changed during which the pulses at the input are counted. - If the frequency counter is being used to measure shortwave receivers or transmitters, you may need to add or subtract the frequency offset value from the measured frequency. The offset frequency is in many cases equal to the intermediate frequency, since the frequency counter is usually connected to the receiver's variable frequency oscillator.
- To measure the generation frequency of a quartz, simply connect it to the connector labeled "Crystal under test"
Additional Information
Key features:
Frequency measurement range: 1Hz - 50MHz
Measurement of general purpose quartz in the generation frequency in the range: 1 MHz - 50 MHz
Automatic range switching
Programmable settings for the added and subtracted value of the frequency shift during settings and measurements in VHF receivers and transmitters.
Maximum input voltage 5 Volts
Energy-saving mode when powered from an independent power source
It is possible to use 5V from the USB interface
Minimum number of components, easy assembly and setup
Questions and answers
- Hello, can I order this product in quantity of 1 piece?
- Yes, of course you can!
- Hello. What voltage range of the measured frequency is acceptable at the input in the frequency counter mode?
- TTL logic level, up to 5 Volts
- Hello. What is the maximum input voltage for this frequency counter?
- 5 Volt
- Hello, when will this construction set go on sale, in particular, in the Chip and Dip store?
- Good afternoon The product is now at the stage of acceptance to the warehouse of finished products, I think within a week it will be available for order through our online store. Regarding Chip and Deep - this question should be asked directly to them.
- Good day! Tell me what's the matter. The frequency meter always shows the same number. 65.370
- This is the first time we hear about such a problem. when properly assembled, the device starts working immediately and does not require configuration. See installation and correct installation of all components. The value of the constant resistors before installation must be controlled with a multimeter.
