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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 in measurements with a five-digit LED indicator, convenient and intuitive.
Main features:
Frequency measurement range: 1 Hz - 50 MHz
Measurement of quartz for general use in generation frequency in the range: 1 MHz - 50 MHz
Automatic band switching
Programmable settings for the added and subtracted value of the frequency shift during adjustments and measurements in VHF receivers and transmitters.
Maximum input voltage 5 Volts
Energy saving mode when powered from an autonomous current source
It is possible to use 5V from the USB interface
Minimum number of components, simple assembly and configuration
The stereo volume, balance and tone control on the TCA5550 has the following parameters: Low nonlinear distortion no more than 0.1% Supply voltage 10-16V (12V nominal) Current consumption 15...30mA Input voltage 0.5V (gain at a supply voltage of 12V unit) Tone adjustment range -14...+14dB Balance adjustment range 3dB Difference between channels 45dB Signal to noise ratio...
The schematic diagram of the transmitter is shown in Fig. 1. The transmitter (27 MHz) produces a power of about 0.5 W. A 1 m long wire is used as an antenna. The transmitter consists of 3 stages - a master oscillator (VT1), a power amplifier (VT2) and a manipulator (VT3). The frequency of the master oscillator is set square. resonator Q1 at a frequency of 27 MHz. The generator is loaded on the circuit...
Amplifier parameters: Total range of reproduced frequencies 12...20000 Hz Maximum output power of mid-high frequency channels (Rn = 2.7 Ohm, Up = 14V) 2*12 W Maximum output power of low-frequency channel (Rn = 4 Ohm, Up = 14 V) 24 W Nominal power of mid-range HF channels at THD 0.2% 2*8W Rated power of the LF channel at THD 0.2% 14W Maximum current consumption 8 A In this circuit, A1 is an HF-MF amplifier, and ...
The VHF receiver operates in the range 64-108 MHz. The receiver circuit is based on 2 microcircuits: K174XA34 and VA5386; in addition, the circuit contains 17 capacitors and only 2 resistors. There is one oscillatory circuit, heterodyne. A1 has a superheterodyne VHF-FM without ULF. The signal from the antenna is supplied through C1 to the input of the IF chip A1 (pin 12). The station is tuned in...
I would like to say right away that It is not possible to check the quartz resonator using a multimeter. To check a quartz resonator using an oscilloscope, you need to connect the probe to one of the quartz terminals, and the earth crocodile to the other, but this method does not always give a positive result, the following describes why.
One of the main reasons for the failure of a quartz resonator is a banal fall, so if the TV remote control or car alarm key fob stops working, then the first thing you need to do is check it. It is not always possible to check the generation on the board because the oscilloscope probe has a certain capacitance, which is usually about 100pF, that is, when connecting the oscilloscope probe, we connect a capacitor with a nominal value of 100pF. Since the capacitance ratings in quartz oscillator circuits are tens and hundreds of picofarads, less often nanofarads, the connection of such a capacitance introduces a significant error into the design parameters of the circuit and, accordingly, can lead to generation failure. The probe capacitance can be reduced to 20pF by setting the divider to 10, but this does not always help.
Based on what was written above, we can conclude that to test a quartz resonator, you need a circuit, when connected to which the oscilloscope probe will not disrupt the generation, that is, the circuit should not sense the capacitance of the probe. The choice fell on a Clapp generator with transistors, and in order to prevent generation from being interrupted, an emitter follower was connected to the output.
I didn’t find a quartz resonator with a frequency higher than 32MHz, but even this result can be considered excellent.
Obviously, for a novice radio amateur, a method without using an expensive oscilloscope is preferable, so below is a diagram for checking quartz using an LED. The maximum quartz frequency that I was able to test using this circuit is 14MHz, the next value I had was 32MHz, but with it the generator did not start, but there is a long gap from 14MHz to 32MHz, most likely it will work up to 20MHz.
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 markings. Traveling through the vast expanses of the Internet and trying to assemble and run various quartz tester circuits, it was decided to come up with something of our own. After many experiments with different generators, both on different digital logics and on transistors, I chose the 74HC4060, although it was also not possible to eliminate self-oscillations, but as it turned out, this does not create interference during the operation of the device.
Quartz meter circuit
The device is based on two CD74HC4060 generators (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-frequency ones I had were hour quartz, and the highest frequency was non-harmonic quartz at 30 MHz. Due to their tendency to self-excite, it was decided to switch the generators simply by switching the supply voltage, which is indicated by the corresponding LEDs. After the generators, I installed a logic repeater. It might be better to install capacitors instead of resistors R6 and R7 (I haven’t checked it myself).
As it turned out, the device runs not only quartz, but also all sorts of filters with two or more legs, which were successfully connected to the appropriate connectors. One “biped” similar to a ceramic capacitor was launched at 4 MHz, which was later successfully used instead of a quartz resonator.
The photographs show that two types of connectors are used to test radio components. The first is made from parts of panels - for lead-out parts, and the second is a fragment of the board glued and soldered to the tracks through the corresponding holes - for SMD quartz resonators. To display information, a simplified frequency meter is used on a PIC16F628 or PIC16F628A microcontroller, which automatically switches the measurement limit, that is, the frequency on the indicator will be either in kHz or MHz. About the 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 at the top left), contacts 15 and 16, which serve for illumination, are not routed, but anyone who needs can add tracks and details for themselves. I didn’t turn on the backlight because I used a non-backlit indicator from some phone on the same controller, but at first there was a Winstar one. In addition to WH1601A, you can use WH1602B - two-line, but the second line will not be used. Instead of a transistor in the circuit, you can use any of the same conductivity, preferably with a larger h21. The board has two power inputs, one from a mini USB, the other through a bridge and 7805. There is also space for a stabilizer in another case.
Device setup
When tuning with the S1 button, turn on the low-frequency mode (the VD1 LED will light up) and by inserting a quartz resonator at 32768 Hz into the corresponding connector (preferably from the computer motherboard), use the tuning capacitor C11 to set the frequency on the indicator to 32768 Hz. Resistor R8 sets the maximum sensitivity. All files - boards, firmware, datasheets for the radio elements used and more, download in the archive. The author of the project is nefedot.
ARCHIVE:
4 quartz resonator testers 
The correct functioning of a quartz crystal can be tested by connecting it to an oscillator or filter circuit. Figure 1 shows a diagram developed by K. Tavernier (France).
Since the crystal frequencies involved 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 quartz under test is working, then a pseudo-sine wave 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 on capacitor C4 reaches a value sufficient to open transistor T2, the LED in the collector circuit T2 begins to light. This indicates the serviceability of the quartz. To determine the oscillation frequency, you can connect a frequency meter or oscilloscope in parallel with resistor R2.
Figure 2 shows a sound tester from the “abroad” section of RADIO magazine No. 12, 1998.
The 4060 chip is a binary counter that includes an oscillator. If you assemble this circuit, generation occurs at the fundamental frequency of the resonator. The chip's dividers then lower the frequency to the audio frequency, which is audible in the low-impedance audio head. The test prototype worked confidently 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 type 1051HL2. 
Figure 3 shows a tester that I whipped up 5-6 years ago. There are plenty of similar schemes in the literature and on the Internet. In this circuit, quartz 1...30 MHz is started. Using microammeter readings, the activity of quartz can be assessed.
It should be borne in mind that quartz crystals with a frequency above 20 MHz are, as a rule, harmonic. Therefore, when testing quartz at 32 MHz, it “started up” at its main frequency of 10.67 MHz, which is what the frequency meter showed.
As it is soldered, it is stored in a box, the board and case are a bummer.
The wideband generator is, of course, versatile and, in most cases, useful. However, low-active quartz may not start in it. But you shouldn't rush to throw it away. In this case, you can adjust the values of capacitors C1 and C2, as recommended in [Radiohobby 1999№3s22-23]. For best excitation conditions, C1 should be approximately numerically equal to the wavelength in meters generated by the quartz (at the first, fundamental harmonic). For example, if the quartz is at 1 MHz, then C1 = 300 pF. For better self-excitation, C2 can be selected 1.5...2 times less than capacity C1. For C3, the capacity is approximately equal to C2 (Fig. 4) 
