How to tune in to a radio station on a radio. High frequency block setting. Placement of elements on the board
With the help of the radio, you can pass the time on the road. Usually, drivers prefer to listen to unobtrusive music so that it plays in the background and does not interfere with steering. For this, autoradio is most suitable, which must first be configured. But many do not know how to properly tune the radio on the radio in the car.
Basically, setting up the radio consists of a few simple steps. A broadcasting band is selected and a search is made for radio channels that are stored in the tuner's memory. The search for radio stations occurs either in automatic or in manual mode. In the first case, radio channels are stored in descending order of broadcast quality.
Let's take a closer look at how to tune the radio on common car radios.
Pioneer
If you are wondering how to set up the radio on the Pioneer radio, do not worry, the setup is very easy. At automatic tuning Pioneer is pressed FUNC, followed by BSM. To start the search for radio channels, press the button to the right or up, after the end, the music of the first found radio station will turn on.
For manual installation in BAND mode, long press >>|. A search for any first station within that radius will be started. After that, the unit will stop scanning and start playing the found station. Then you will need to save it, for this, hold the key with the desired number for a long time. If you do not need the found station, you need to press the key to the right and hold it. Scanning will continue until a new station is found.
With this function, you can memorize up to 6 stations in the first bank. After this manipulation, press the BAND button and get into the second bank, it is shown on the display as F2. In the second bank, up to 6 stations can be memorized in the same way, and there is also a third bank. Most often there are three banks, but there are more. As a result, if you have three banks, you will have 18 stations active and saved. Now you know how to set up the radio on the Pioneer radio.
Sony
Setting up the radio in the Sony radio is also not a problem. The search for stations is usually carried out in two common ways: manually or automatically. Automatic storage of radio stations:
- Turn on the radio. Long pressing the Source button, wait until the message TUNER appears on the display.
- The range change occurs when the Mode button is pressed. If you press the joystick controller, the options menu will be displayed.
- Turn the joystick until the inscription of the TTM option appears. Radio channels are assigned to number keys as standard.
To manually scan and save, you must:
- Turn on the radio and start searching for stations.
- After the desired radio station is found, you need to press the number key from 1 to 6, after which the name "Mem" will appear. Note: when you store a radio station on a digit that already has a radio station, the previous one is automatically erased.
Thus, you can set up the radio in the Sony radio in 5-10 minutes.
Supra
After pressing the MODE button, select the Radio function, then RADIO and the saved band with the broadcast frequency will be displayed on the screen. Pressing BND selects the desired broadcast band.
Press and hold the >>|| button.
Then press the button >>|| to select the desired station. If these keys are not pressed for up to ten seconds, everything will return to its original mode of operation.
Setting in automatic mode and scanning for selected radio stations
Search for existing radio stations:
By briefly pressing the AS/PS key, start searching for stored radio channels. Any station can be listened to for about a couple of seconds. For auto save radio channels, hold down the AS/PS key. The receiver will tune in the six best stations that are the strongest in that broadcast band. This option can be applied in any wave range. When the automatic storage of stations is completed, the receiver will stop scanning them.
To tune in to a specific radio station, press the >>|| button, this will scan and select radio channels from the best signal reception. By pressing the >>|| button, you can manually select the station you want. Hold down a key with numbers from 1 to 6 for about a couple of seconds to memorize the channel under the desired key.
JVS
When tuning stations, it is possible to leave 30 FM radio channels and 15 AM channels in the tuner.
Setting stations manually:
- Select a broadcast band by pressing the TUNER BAND key.
- Click button 4 to set up the station.
- Hold the key with any selected number on the panel to memorize the station in the radio's memory. The favorite number will start flashing, and then you will see the station stored under the selected number. For example: To tune in the station number 14, press the +10 key and then the 4 key for about three seconds or more.
- To store other radio stations in the device's memory, repeat steps one through three. And to change the settings of the entire station, you need to repeat the whole process from the beginning.
Tuning stations in automatic mode:
Stations will be given numbers by increasing the range frequency.
- Select the range by pressing the TUNER BAND key.
- Press and hold the AUTO PRESET button on the panel.
- To set a different range, you need to go through the steps from the first to the second again.
To replace the selected stations in automatic mode, you must use manual installation.
Kenwood
Kenwood radios offer three types of autoradio settings: automatic (AUTO), local (LO.S.) and manual.
- Press SRC until "TUnE" appears.
- Press FM or AM to select a band.
Press >>| or |.
In the case of manual tuning, after all the above actions, ST will light up, indicating the found station.
Setting up a transistor receiver, in principle, differs little from setting up a tube receiver. After making sure that the bass amplifier is fixed and the tubes or transistors of the receiver are operating in normal modes, they begin to tune the circuits. The tuning starts with the detector stage, then goes to the IF amplifier, local oscillator and input circuits.
It is best to tune the contours with a generator high frequency. If it is not there, then you can tune by ear, according to the received radio stations. In this case, only an avometer of any type (TT-1, VK7-1) and another receiver may be required, the intermediate frequency of which is equal to the intermediate frequency of the tuned receiver, but sometimes they are tuned without any instruments. The autometer during adjustment serves as an indicator of the output signal.
When setting up the IF amplifier circuits in tube receiver when an RF generator and a tube voltmeter are used for this purpose, the latter must not be connected to the grid of the lamp, since the input capacitance of the voltmeter is added to the capacitance of the grid circuit. When adjusting the circuits, the voltmeter should be connected to the anode of the next lamp. In this case, the circuit in the anode circuit of this lamp must be shunted with a resistor with a resistance of about 500 - 1000 Ohms.
Having finished setting up the IF gain path, they begin to set up the local oscillator and the RF amplifier. If the receiver has several bands, then the tuning starts with the KB band, and then proceed to the tuning.
Contours SV and DV ranges. Short-wave coils (and sometimes medium-wave ones), unlike long-wave ones, usually do not have cores; they are wound most often on cylindrical (and sometimes on ribbed) frames. The change in the inductance of such coils is carried out when adjusting the circuits, shifting or pushing the turns of the coils.
In order to determine whether the coils should be shifted or moved apart in a given circuit, it is necessary to bring a piece of ferrite and a brass (or copper) rod into the coil or alternately bring it closer to it. It is even more convenient to perform this operation if, instead of a separate piece of ferrite and a brass rod, a special combined indicator stick is used, at one end of which magnetite (ferrite) is fixed, and at the other - a brass rod.
The inductance of the coil of the RF amplifier circuit should be increased if, at the junction points of the circuits, the volume of the signal at the output of the receiver increases when ferrite is introduced into the coil and decreases when a brass rod is inserted, and vice versa, the inductance should be reduced if the volume increases when the brass rod is inserted and decreases with the introduction of ferrite. If the circuit is configured correctly, the weakening of the signal volume at the junction points occurs with the introduction of both ferrite and brass rods.
The contours of the MW and LW ranges are adjusted in the same order. The change in the inductance of the loop coil at the junction points is carried out on these ranges by appropriately adjusting the ferrite core.
When making homemade contour coils, it is recommended to wind a few obviously extra turns. If, when tuning the circuits, it turns out that the inductance of the circuit coil is insufficient, winding the turns on the finished coil will be much more difficult than winding the extra turns during the tuning process itself.
To facilitate the adjustment of the contours and graduation of the scale, you can use the factory receiver. Comparing the angles of rotation of the axes of the variable capacitors of the tuned receiver and the factory one (if the blocks are the same) or the position of the scale indicators, it is determined in which direction the circuit setting should be shifted. If the station on the scale of the tuned receiver is closer to the top of the scale than the factory one, then the capacitance of the tuning capacitor of the local oscillator circuit should be reduced, and vice versa, if closer to the middle of the scale, increase.
Methods for testing the local oscillator in a tube receiver. You can check if the local oscillator is working in a tube receiver. different ways: using a voltmeter, optical tuning indicator, etc.
When using a voltmeter, it is connected in parallel with the resistor in the anode circuit of the local oscillator. If the short circuit of the capacitor plates in the local oscillator circuit causes an increase in the voltmeter readings, then the local oscillator is working. The voltmeter must have a resistance of at least 1000 ohm / V and be set to a measurement limit of 100 - 150 V.
Checking the performance of the local oscillator with an optical tuning indicator (6E5C lamp) is also simple. To do this, the control grid of the local oscillator lamp is connected with a short conductor to the grid of the 6E5C lamp through a resistor with a resistance of 0.5 - 2 MΩ. Dark sector of the tuning indicator when normal operation the local oscillator must be completely closed. By changing the dark sector of the 6E5C lamp when turning the receiver tuning knob, one can judge the change in the amplitude of the generator voltage in different parts of the range. If the amplitude unevenness is observed within a significant range, more uniform generation over the range can be achieved by selecting the number of turns of the coupling coil.
The operation of the local oscillator of the transistor receiver is checked by measuring the voltage at the load of the local oscillator (most often at the emitter of the transistor of the frequency converter or mixer). The local oscillator voltage, at which frequency conversion is most effective, lies in the range of 80 - 150 mV in all ranges. Measurement of the voltage at the load is carried out with a lamp voltmeter (VZ-2A, VZ-3, etc.). When the local oscillator circuit is closed, its oscillations break down, which can be noted by measuring the voltage at its load.
Sometimes self-excitation can be eliminated very simple ways. So, in order to eliminate self-excitation in the IF amplification stage, a resistor with a resistance of 100 - 150 Ohms can be included in the control grid circuit of the lamp of this stage. In this case, the intermediate frequency voltage gain in the cascade will decrease slightly, since only a small part of the input signal voltage is lost on the resistance.
In transistor receivers, self-excitation can be observed if the battery of cells or batteries is discharged. In this case, the battery should be replaced and the batteries put on charge.
In a number of cases, self-excitation in the receiver and TV can also be eliminated by such measures as transferring the grounding of individual circuit elements, altering the installation, etc. The effectiveness of the measures taken to combat self-excitation can often be assessed in the following way.
Rice. 25. To an explanation of the method for eliminating self-excitation in transistor reflex receivers
The receiver or TV is connected to an adjustable power source (that is, to a source whose voltage supplied to the anode circuits can be varied over a wide range), and a tube voltmeter or other dial indicator is turned on at the receiver output. Since at the moment of self-excitation, the voltage at the output of the receiver changes dramatically, the deviation of the indicator arrow makes it easy to note this. The voltage taken from the source is controlled by a voltmeter.
If self-excitation occurs at rated voltage, then the supply voltage is reduced to a value at which generation stops. Then they take certain measures against self-excitation and increase the voltage until generation occurs, marking it on a voltmeter. In the case of successfully taken measures, the self-excitation threshold should increase significantly.
In transistor reflex receivers, self-excitation can occur due to the poor location of the high-frequency transformer (or choke) relative to the magnetic antenna. You can eliminate such self-excitation using a short-circuited coil copper wire with a diameter of 0.6 - 1.0 mm (Fig. 25). A U-shaped wire bracket is threaded through a hole in the board, bent from below, twisted and soldered to the common wire of the receiver. The bracket can serve as an element for fastening the transformer. If the transformer winding is evenly wound on a ferrite ring, then the corresponding orientation of the short-circuited turn relative to other ferrite parts is not required.
Why does the receiver "howl" on the KB band. It can often be observed that a superheterodyne receiver, when receiving a broadcasting station at short waves, begins to “howl” with a slight detuning. However, if the receiver is more accurately tuned to the received station, then reception becomes normal again.
The reason for the "howl" when operating the receiver at short wavelengths is the acoustic coupling between the receiver's loudspeaker and the tuning capacitor bank.
This generation can be eliminated by improving the depreciation of the tuning unit, as well as by reducing various accessible ways acoustic feedback- changing the method of fastening the loudspeaker, etc.
Tuning the IF amplifier with another receiver. At the beginning of this section, a method for tuning a radio receiver using simple instruments was described. In the absence of such devices, the tuning of radio receivers is usually done by ear, without devices. However, it should immediately be said that this method does not provide sufficient tuning accuracy and can only be used as a last resort.
To tune the IF amplifier circuits, instead of the standard signal generator, you can use another receiver, the intermediate frequency of which is equal to the intermediate frequency of the tuned receiver. - For a tuned lamp receiver, the AGC wire from the diode to the control grids of adjustable lamps must be disconnected from the diode during tuning and connected to the chassis. If this is not done, then the AGC system will make it difficult to fine-tune the bandpass filters. In addition, when tuning the IF amplifier, it is necessary to disrupt the oscillations of the local oscillator by blocking its circuit with a capacitor with a capacity of 0.25 - 0.5 microfarads.
The auxiliary receiver used in this case does not need to be subjected to any significant alterations. To set up, you need only a few additional parts: a variable resistor (0.5 - 1 MΩ), two fixed capacitors and two or three fixed resistance resistors.
Setting up the amplifier circuits. IF receiver produced as follows. The auxiliary receiver is pre-tuned to one of the local stations operating in the long or medium wave band. Next, the common wires or chassis of both receivers are connected to each other, and the wire going in the tube receiver to the control grid of the lamp of the first IF amplification stage of the auxiliary receiver is disconnected and connected to the control grid of the lamp of the corresponding IF amplifier stage of the tuned receiver. In the case of tuning a transistor receiver, the IF signal through capacitors with a capacity of 500 - 1000 pF is fed in turn to the bases of the transistors of the corresponding stages of the IF amplifier.
Then both receivers are turned on again, however, in order to avoid interference during tuning, the low-frequency part of the auxiliary, as well as the local oscillator of the tuned receiver, should be turned off (in tube receivers, by removing the lamps of the bass amplifier and local oscillator, respectively).
When setting up the IF amplifier stages of a transistor receiver, its local oscillator should be turned off by installing a jumper in the local oscillator circuit.
After that, by applying an intermediate frequency signal from the auxiliary receiver to the input of the tunable IF amplifier and smoothly adjusting the setting of the IF circuits of the latter, one achieves the audibility of the station to which the auxiliary receiver is tuned. Further, the tuning is continued - separately for each circuit (to the maximum signal level), and the tuning is best done using a pointer device connected to the output of the bass amplifier, or by an optical indicator (6E5C lamp or the like).
Start tuning from the last IF circuit; the signal is fed to the base of the corresponding transistor or directly to the grid of the lamp, in the anode circuit of which the tuned circuit is included.
If the adjustment is carried out not by an optical indicator, but by the sound volume, then it is recommended to set the volume level to the minimum, since the human ear is more sensitive to changes in the volume level with weak sounds.
About tuning the receiver for radio stations. The tuning of a superheterodyne receiver - tube or transistor - for received stations without the use of an auxiliary receiver usually starts on the KB band. By adjusting the IF circuits for maximum noise and rotating the tuning knob, the receiver is set to any of the audible stations. If it is possible to receive such a station, then they immediately begin to adjust the IF circuits, achieving maximum audibility (the tuning starts from the last IF circuit). Then the heterodyne and input circuits are tuned, first on short, then on medium and long waves. It should be noted that tuning receivers using this method is complex, time-consuming and requires experience and skills.
Lamp 6E5C - indicator when setting up. According to the sound volume, it is not recommended to adjust the receiver circuits, as already mentioned, especially if it is installed high level output volume. The sensitivity of the human ear to changes in signal level at loud sounds is very low. Therefore, if you still have to tune the receiver by sound, then the volume control should be set to a low volume level, or, better, use an optical tuning indicator - a 6E5C lamp or another similar one.
Tuning superheterodyne receivers according to received stations and using a 6E5C lamp as an indicator of tuning accuracy, it is more convenient to adjust the circuits at an input signal level at which the dark sector of this lamp narrows to 1 - 2 mm.
To regulate the signal voltage at the receiver input, parallel to the antenna coil, for example, a variable resistance resistor can be connected, the value of which, depending on the sensitivity of the receiver, can be selected in the range from 2 to 10 kOhm.
How to detect a faulty stage in an RF amplifier. When adjusting or repairing a receiver, a cascade in which there is a malfunction can be detected using an antenna, connecting it in turn to the bases of transistors or to the grids of amplifier lamps and determining by ear whether there are malfunctions in these cascades.
This method is convenient to use in cases where there are several stages of RF amplification.
An antenna in the form of a piece of wire can also be used when checking the IF and RF amplification stages in TVs. Since shortwave stations often operate at frequencies close to the intermediate frequency of TVs, listening to these stations will indicate that the sound channel is working,
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once upon a time radio Sony, during the sale they said that it was Japanese, the price made me believe, in the future he himself assured everyone that she was from there. Its objective advantage is pure sound. True, there was a small nuance - the FM range scale was 88-108 MHz, but the store had a magician who, for a "small share", created a miracle - he filled the scale with many Russian-speaking radio stations. Operated the radio full program, but remembering how much was paid for it, they did not throw it or her. So it was not badly preserved, despite the very respectable age. That's just the broadcasting stations that she caught, at first diminished, and then did not remain at all.
On the Internet, about setting up sound-reproducing equipment, there is a sea of information, it is written correctly, in detail. This is happiness for students of radio engineering universities, you can easily use it instead of notes to prepare for exams, and this infa will not help the owner of an ill radio, it’s not for him to increase his intellect, but to repair the receiver. Or throw it away, no worries.
He opened the case, began to disassemble it into its component parts. Neither the power supply, which turned out to be super primitive, which is at the bottom left, nor the tape drive mechanism of the tape recorder, to the right of it, have no complaints. One gives out its 12 V “on the mountain”, and the second regularly pulls the magnetic tape.
And here printed circuit board I wanted to understand a little. To warm up, I checked all electrolytic capacitors for the actual presence of capacitance and ESR. It's hard to believe, but everything turned out to be in perfect order. I soldered and disassembled the volume control - a variable resistor, for example, a revision. Once upon a time, he messed up a little and was, by means of a medical syringe with a needle, awarded a portion of engine oil. Does it need a supplement? And there was so much oil in it that even now in a frying pan - I blotted the excess, returned it to its place. I washed the board from the side of the printed conductors with formic alcohol specially bought at the pharmacy (they didn’t give anything else), and then, so that there was no white coating from it, with hot water and shampoo. It turned out not bad, although it is perceived by ear, this method is wildly.
The wire contacts suitable for the speaker were soldered. And around the circumference of the speaker, he installed a rim - a flexible tube cut along the length from a medical dropper. This is so that the metal of the speaker does not rest on the plastic of the case - it definitely won’t be worse for the sound characteristics.
And then, very opportunely, I remembered that the master who was modifying the radio tape recorder spoke about some kind of wire spirals. There were several of them on the board, and everything was in the region of a variable capacitor. I partially assembled the device, turned it on and, at the desired range, began to touch the copper wires wound with rings with a screwdriver. Two did not respond, but barely touched the third, characteristic changes in sound appeared in the dynamics. Found! Pictured below. I touched it well with tweezers, and it dangles. I soldered it, straightened it and wound it on a new one, on a mandrel of a suitable diameter. Soldered into place. FM band came to life. Then he completely grew bolder and let's move the turns with a screwdriver (increase and decrease the gap between them). In response to my actions, the location and number of stations on the scale began to change. But two tweezers turned out to be the most convenient for tuning. He stretched and squeezed them like an accordion, only gently. You can clearly see this action in the video.
Video
As a result, I chose a combination of stations that was suitable for me and optimal in terms of location on the scale. The only difficulty is to do everything slowly, otherwise, you know, you want to do everything faster. Good luck! Babay iz Barnaula shared the simplest option for a possible restoration repair - settings.
Each radio has settings for a certain frequency, most of them even have fixed ones, which is very convenient. If the receiver is digital, that is, it has electronic tuning, then fixing a particular radio station on a specific channel will not be difficult. This process will be a little more difficult on receivers with a conventional tuning scale. But, in any case, the user manual describes in detail how to tune the radio and how many stations you can store in its memory. However, all this can be done only after the purchase of this very radio. Many people are faced with the problem of choice these days, because there are a lot of all kinds of models in stores.
For those who want to listen to all radio stations, the best option would be all-wave receiver. And if he has the opportunity to receive VHF waves, then it will be just happiness, because such receivers can also catch radio talks. Therefore, it is worth considering how to choose a radio receiver, for what purposes it will be used and what should it be? If this is a "cabinet" receiver, then standard FM and AM bands will be enough for it. For "portable" and "traveling" receivers, it is better to be able to "listen" to all frequencies, since hikes can be in unfamiliar areas where the radio can broadcast on any frequency. "Portable" you can just play around and eavesdrop on other people's conversations if they use walkie-talkies.
If you can’t buy such a receiver, then you should think about how to assemble a radio so that it can “hear” in the right range. To do this, you must be a radio amateur, or have one of them in very close friends. You can, of course, dig around the Internet and look for step by step instructions radio assembly. But there is also underwater rocks, because not all the necessary parts can be bought, some you have to do yourself. Therefore, if there is a radio amateur friend, then you can ask him how the radio works, what parts you can buy, and which ones and how to do it yourself, and most importantly from what? After the answers to the questions are received, you can start searching for the necessary parts, both for the receiver and parts for parts for your radio.
You will have to run a lot around the shops, look for old equipment in the pantry and dig into it in search of the right details. After that, you will have to spend a lot of time with a soldering iron in your hands and use up a few grams of tin and wires. And now, when all the details are ready, it will be necessary to turn to a friend with the question of how to make a radio receiver so that it works reliably and for a long time. What will be the radio, it does not matter much. Both homemade and purchased receivers receive radio waves. If he brings pleasure to his master, then he will fulfill his destiny.
With just one chip, you will need to build a simple and complete FM receiver that is capable of receiving radio stations in the 75-120 MHz range. The FM receiver contains a minimum of parts, and its setup, after assembly, is reduced to a minimum. It also has good sensitivity for VHF reception FM radio stations.
All this thanks to the Philips TDA7000 chip, which can be bought without problems on our favorite Ali Express -.
Receiver circuit
Here is the receiver schematic. Two more microcircuits are added to it, so that in the end we get a completely finished device. Let's start looking at the diagram from right to left. On the LM386 running chip, a low-frequency amplifier for a small dynamic head, which has already become a classic, is assembled. Here, I think, everything is clear. The variable resistor controls the volume of the receiver. Further, a stabilizer 7805 is added above, which converts and stabilizes the supply voltage up to 5 V. Which is needed to power the receiver's microcircuit. And finally, the receiver itself is assembled on the TDA7000. Both coils contain 4.5 turns of wire PEV-2 0.5 with a winding diameter of 5 mm. The second coil is wound on a frame with a ferrite trimmer. The receiver is tuned to a frequency variable resistor. The voltage from which it goes to the varicap, which in turn changes its capacitance.If desired, from the varicap and electronic control you can refuse. And the frequency can be tuned either with a tuning core or a variable capacitor.
FM receiver board
I drew the circuit board for the receiver in such a way as not to drill holes in it, but to solder everything from the top, as with SMD components.Placement of elements on the board
Used the classic LUT technology for the production of the board.
I printed it out, warmed it up with an iron, etched it and washed off the toner.
Soldered all the elements.
