Before the end of this fate, I had embraced my love for “Ocean 214” and, seemingly embarrassed, there was nothing to hear. “Our” radio from our Omsk wilderness was calling happily (well, what an increase in stench they wanted to eliminate on the UKH-1 range!), and “Mayak” remained completely populated and was sulking in a 24/7 manner. About other FM (that’s right! After a few steps, my Ocean can receive the European band). The first axis from now until spring was covered with a saw and pretended to be a bedside table. And at this hour I sat down and got busy with audiobooks. Tsikav me peredusim format AWB This work was created on personal computers (on a smart phone it’s not so easy - you have to constantly pause and take off your headphones to talk to people). I wrote the program (lay it by my side), but why create it? Of the available computers, only my netbook, (which is already the third generation of simple myths about those who need only the Internet), the weight and brightness of the speakers on this one deprive it of the best. It dawned on me - Primach! The axis on which you can create books, because the speaker is so truly Radian! How can I get the laptop from 2008 to the 1986 (26.4.1986 between the two!) rock? The wires are not visible - even different standards, and the ugly wire that hangs in the middle of the room. Todi without darts. My head started pounding: “The laptop has WI-FI.” So, there is nothing to be said about it. Having started the kolupati. If Wi-Fi does not receive a radio signal, you can lower the frequency to the current 88-108 mhz and use the same modulation. It is useful to search for FM broadcasts for a PC (similar to an FM tuner). Znayshov. Expensive to set up, low intensity, maximum range - 3 meters in an open field. Let's throw in an idea. I also knew about car transmitters that are inserted into the cigarette lighter socket. Having dissected the brushes and read the relevant articles within reason, since they are reading flash drives that require 5V, then they themselves are guilty of stress. Use the joke. Znayshov. Definitely cheap and very legal (fm bands require a license), not so compact - I can correct the circuit, extend it wider. Please try it. Buying the Chinese “Profile EX-06”, the price is 600 rubles. It's cheap, doesn't have any fancy features, but it's not a bad thing. Come on, let's see.

We need:

1. The FM transmitter itself has a power rating of 10 MW ( Respect! 10 mW is the maximum permissible voltage, which does not require registration with the State Communications Supervision Authority). Modulator obov'yazkovo may be equipped with a linear input for transmitting sound directly from a computer/laptop/phone. If you only want to transfer music from a flash drive, then the line input is not obligatory
2. Soldering iron, solder and a thin tip (I soldered with extreme ease and without ruining the micro-piece)
3. USB cable (whatever you want to plug into your computer with one end)
4. A set of screws for disassembling steel wires (for the need for tricky screws and the need to seal the edges of the front mask)
5. Tweezers (I got by without it, but only because I didn’t have it)
6. Small telescopic antenna (to increase the radius. If the required range does not exceed 2 meters, then it is not required)
7. Power supply for 12 and 5 volts (as long as it is not shortened, you can remove 5 volts from the USB port, using the standard 4.5v)
8. Glue (less than a second one based on cyanoacrylate)

So let's finish:

1. Select FM transmission from the front panel. Most of these devices are assembled with disposable clamps, but mine has a screw. So don't overdo it. It would be ideal to use a knife and a small slotted screw and press one fastener, and then use the same screw to push in all the others (whoever, even if you take apart the phone and laptop once, will not recognize the difficulties).

2. Next, we remove the board (in mine, it is tightly sewn to the player’s board with a cable - the end of which is simply pulled out) and apparently marked “DC5V” - this is exactly the 5-volt power supply. If there is nothing wrong with it, then it’s like this: the original 12 volts are heated on the cigarette socket and the odd stench turns to 5. A memorized place and after turning on the 12-volt power supply is heated before the start. +5V (minus can be used as standard) . For those who don’t smoke cigarettes, I’ll tell you: +12V is a small contact in the center, and 2 voltages on the sides are a minus (later, for my ignorance and illiteracy, the minus is called “mass”).

3. Once you have found the location, you can power the device with five volts by cutting a power cable. The original USB cable standard 1.0 (including 2.0 - there are the most of them) contains (except braided) 4 cables. Greens and whites can be cut immediately - but purely for data. We need blacks and reds. Chervony tse plus, black - masa. We will clean up and clean any cables that have become loose. It’s better to learn them right away (for those who are sold first, it’s a good idea to read the pre-science literature right away).

4. Now let's cut through this cable near the transmission housing. I did this: I first heated the head with a soldering iron and pierced the body. Then, using a screwdriver and different drill bits, step by step (so as not to crack the body), increasing the diameter to the required one. Respect! Be sure to open without blocking anything (thread or microcircuit)

5. Now insert the cable into the hole and secure it in the middle with some superglue. Take 2 darts from the third point (we released them from stock, right?) and solder them with a thin tip (do not seal the microcontroller!) to the contacts from point 2.

6. Without closing the case, run to the nearest computer for testing. If the modulator is plugged in, and there is no dark smoke from the computer, then you have done everything well and can close the case. In my case, the pins turned out to be even worse and I had to use the same superglue.

7. And I was already pleased to hear my favorite music on my favorite receiver, but, having gone a couple of meters away, I realized that the sound was completely familiar. Marries far-rangingness. As a quick fix, you can put a lot of stuff in the antenna’s core, or rather take a walk to the radio goods kiosk (and if you read the section “we’ll need it,” then you’ve already taken a walk) and buy a not-so-large antenna. A small antenna is needed for two reasons: firstly, the modulator is not particularly important and the long antenna, straight up, is more important, and otherwise the long antenna has a long range, and we don’t need the station to sense everything one hundred ( Please remember that a license is required to communicate in the UKH range). 30-45 cm would be the shortest option.

8. “Where should I put it?” - the nutritional axis that you are constantly wondering about. There are only a few options, but I’ll do it in the simplest way. I inserted the antenna there, before making the central contact for the cigarette lighter. As soon as you are in control, it’s easy to do the following: screw the lid of the rosette and twist it to remove the “pumpkin” (who can come up with a more adequate name?) and the companion. We wrap the antenna with electrical tape in the place where it will be inserted into the niche that has been assembled (or we will customize the niche itself to the required parameters) so that it is lightly pressed onto the spring (there is no need to tighten the spring! Insert on the m I'm sorry!) and screw the lid on.

9. As a result, approximately such a device is recovered, with a radius of approximately 300 meters. Whose whole thing should be used to “distribute the radio around the house or around the neighbors’ house.” There is such a “child” with a storage capacity of almost 120 mAh and it drains my laptop battery in 6 short years (at the same time as written in this article). The only inconvenience was the need to draw 2 cords (the cable from the headphone socket to the modulator socket and the USB connection).

10. Dekilka rad shodo vikoristannya:

What you need now is what you have already earned/are going to earn:

1. Listen to good music on the FM band, without damaging the flash card of your phone/player. Here, just like with a WI-FI router, the principle applies: “One distributes, everyone shares.” There is no need to connect, of course - radio!
2. Your own radio station! Let it go and put little effort, let’s say, as soon as the radio station is ready to go.
3. Sponsor in front of others: “Check, I’ll pause the radio and let’s talk”
4. Find good sound on your laptop!
5. For me: get out of retirement, old trick!
6. You can re-listen for a long time!

Receiving a signal in the simplest way today, radio transmission to the UKH is carried out on a standard one (portable, landline, used by a landline phone), at a frequency of 90-100 megahertz. The circuit is very simple and a reminder for people who are just beginning their radio activities, it is not a great idea.

Radio parts and ready-made radio stations with cost-free delivery from this Chinese store.
turns around to you.

This can be used for a variety of standard tasks, for example:
1) drone-free headphones.
2) Electronic nanny to control non-catching.
3) Bug for stitching.

The presented option is used as a prefix to transform the original headphones into wireless ones. The radio broadcast is turned on before the headphone socket of your TV, so replacing the wires will now be a simple circuit. You can protect such further investigation by making the device with your own hands.

For work we need:
Soldering iron.
Honey darts.
A plug that corresponds to what is used to connect headphones to a 3.5 mm TV socket.
Batteries have a voltage of 3 to 9 volts.
Copper wire with varnished shell (vikorist type is available for the coil).
Use Moment glue once in a while.
Pay as much as possible (as possible).
A cut of textolite or cardboard.

Simple transmission circuit

All necessary radio components for transmission

The bobbin needs to be wound 7-8 turns with a copper varnished drill with a diameter of 0.6-1 millimeters, on a tube with a diameter of 5 millimeters, for example, you can turn the drill bit 5). The ends of the darts on the mat are cleaned with varnish.

For a closed transmission housing on one transistor, you can use a separate box. At the pointed butt there is a container for batteries, from which all parts of the partition and other parts have been removed.

Now the required size of the panel is made from textolite and we can prepare without openings for the parts. The more of them you have, the easier it will be to keep away the folding and soldering of parts.

Now we need to solder the plug to the plug in line with the circuit (the part that is the input)

At the next stage, we put the circuit assembled on the board in a box; to be safe, you can secure it with some kind of glue, otherwise it won’t be too tough. Quilt the tops so that everything is neatly folded during operation of radio transmissions

Our transmission has lost its way. For which additional plug is connected to the TV. On FM (UHF), for example, on a mobile phone we find a different frequency (so that there is no transmission of any radio station) and we tune our device to this channel. Frequency regulation is effected by an adjusting capacitor using additional twisting. Smoothly wraps around until you show up on FM, picking up the sound from the turned off TV.

That's all, you can turn on the headphones on your mobile phone and watch TV without worrying about the noise that might displease others.

To make adjustments so as not to permanently open the housing, make an opening at the transmission housing.

If you replace the audio plug with a microphone, then you will have a radio broadcast that you can place next to the baby and turn off the radio in another room to know that the baby has woken up, etc.

Shvidshe for everything, I'll hit you up.

Stereo FM transmission on BH1417

On the BH1417 microcircuit it is easy to manually construct various radio transmissions with a stereo encoder.
The BH1417 microcircuit contains an input low-frequency booster, low-pass filter, stereo encoder, radio frequency stability control system, FM modulator, radio frequency booster. Everything is collected in one case, there is no need to add any hanging elements. To operate microcircuits, you need a quartz resonator with a frequency of 7.6 MHz, since one is not available, it can be replaced with a resonator with a frequency of 7.68 MHz. The microcircuit operates under a voltage of 4-6 volts and maintains only 30 mA, resulting in a power output of about 20 mW to the radio channel. The output frequency is regulated by additional micro-switches S1-S4, in some devices they are used daily, instead of them they are vicorized either by jumpers on the board, or by an external microcontroller. Based on BH1417 microcircuits, various FM modulators for cars, USB microtransmissions for broadcasting music from a computer and other devices that require transmission via a radio channel of a stereo audio signal in the FM range are produced i. To increase the output power of transmission, and therefore the range of transmission, manufacturers, as well as folk craftsmen, provide devices for increasing pressure. Some devices based on the BH1417 microcircuits can be seen in the little ones below.

The radio transmitter, whose circuit is aimed at the baby below, operates at a frequency of 88-108 MHz, the transmission range of the radio signal becomes 1 to 5 kilometers, depending on the connection of the circuit.

The circuit has widely available radio electronic components. The circuit can be powered by either a 9V voltage source or a KRONA battery or a fringe power supply unit.

Principle diagram

On the first transistor there is a generator and a modulator that sets. The high intensity of radio transmission is achieved through the action of the secondary HF amplification cascade, collected on the KT610 transistor, and the front HF amplification cascade, collected on the KT315 transistor.

Since such transmission intensity is not required, the circuit can be simply simplified by turning on the RF signal amplification cascade, in which the cascade is shown in a blue block. The antenna in this configuration is connected to the middle input of the L3 coil. Thus, the intensity of radio transmission will decrease and the range of the radio transmission will be 800m - 1km.

If you need a range of about 50-200 meters, you can turn off the RF amplification cascade on the KT610 and KT315 transistors, excluding only the generator that sets the first transistor (circuiting the gray rectifier). In this case, the L2 coil is no longer needed; the antenna is connected through a 5-10 pF capacitor to the collector of the transistor in the generator that sets it.

#24 Andriy Berezen 17 2015

and what is the scheme itself for a continuous broadcast over 3-5 km, but with a clearly fixed signal (so that there would be no problems with the signal at the reception)?

#25 Konstantin Cherven 08 2015

What is the diagram of a transmission similar to the tightness, but stable, with a varicap?
I’m asking from home to the dacha plot, it’s time to run and lighten up. The neighbors praise the idea, but also ask for stability. It’s funny to go out: it stinks to soften my reception, I dance with a tambourine around the transmission, and all at the same time sweeten my reception once again. I'll ring a stake in about an hour.

#26 root Worm 09 2015

Radio transmission axis with output pressure of 100-200 mW and with varicap: Scheme of pressure radio transmission with emergency response at 65-108 MHz.

It is also necessary to ensure that the frequency does not float and the transmissions operate stably, it is necessary to clearly stabilize the life cycle.

#27 NULL Worm 16 2015

Hello, please please
Having selected this transmission from the option with the first two cascades, “earning” almost immediately.
First of all, the power supply is due to the design: two coils of 3 turns each, how do you solve L3, how do you need to rotate it? On one axis, the handles are one after another or parallel to one to another? I moved on one axis.
Now it’s time to work: how to verify the effectiveness of another cascade? The problem is that the transmission is working, but very weakly, the range is 1-2 meters, far away. The frequency changes miraculously. Yak priymach vikoristuyu smartphone with headphones.
Because Dzherelo - line output, removing the resistor to 2k, replacing the capacitor with 5 uF by putting 0.22 uF ceramic, replacing the 100k resistor by putting 75k, and putting the new 100k to ground.
Replacing capacitors with 120pf by setting 100pf.
An important point: all capacitors are permanent. The frequency is changing, the core of the plastic frame L1 is smoking.
The transistors are installed at a frequency above 100 MHz: 1st stage - 2SC1740, 2nd stage - 2SD667. Antenna - 30 cm length of dart. Zhyvlennya - 12V battery.
The following cautions: when the circuits were used outside, 7-8 mA came out, which seems to be a failure. As soon as you push the antenna with your hand, the generation starts, and I don’t understand, even if the antenna is connected to another cascade, but it doesn’t give a sign of life. The resistor in the other cascade is changed to 1 MΩ, its wrapping does not give anything. Nyumu's transistor is cold. Before soldering, the wine was 100% robotic with hfe 130.
I guess so. The fragments of the first cascade, which you can’t paw with your hands, stably generates, then dig, I guess, you need another. What kind of gratification will you give? Why is it so small that the first cascade has a distance of 1-2m, but not through those whose antenna is connected to the other?
Unfortunately, I don’t understand how another cascade works. What is the capacity of the row capacitor used for? So I am in tsikh _radio_ on the right, maybe 0.

#28 root Worm 17 2015

The wrong parts of the L3 coil rotate on the same axis, you have assembled everything correctly.
The first thing to do before adjusting the other cascade is to turn it on completely and adjust the first cascade with the generator so that the new signal is transmitted over several tens of meters.
Connecting to the line output, the fragments you wrote, may be the cause of the overflow and loss of tension, which is lost. It is necessary to achieve stable operation of the generator by selecting resistors that are connected to the base.
You can try to select the first stage behind the whole circuit and connect another stage to the next one to increase the HF intensity.
Also, to improve the situation, you can try to remove the additional low-frequency stage on a transistor, and then connect the signal source.
Screwing the core into the L1 frame is not a very good idea, try to remove the old capacitor here and check the work from the second one through the new one.
With a 12V support resistor in the generator supply voltage (380 Ohm), try increasing it.
Turn the transistor over in another cascade - it may already burn out, for experiments you can solder a new one and, while the emitter is running, turn on the resistor with a support of approximately 200-300 Ohms, if the other stage requests, select the most distant support.

#29 NULL Cherven 17 2015

Thanks for the comments.
So, now that I’ve ruined myself, you start working with the drive of the first cascade - I’ll start with this one. I have been collecting a similar 1-transistor transmission for a long time, as per your instructions, in between the apartments I worked and I used it, and from the delivery to the private booth, it turned out that the tension of the lack: in the lot, behind the walls of the booth ku signal already beep with recodes. Recently I needed transmission again and decided to try a 2-3 transistor circuit.
As soon as I have an hour, I’ll try to experiment: I’ll twist the core, solder in a high-capacity loop capacitor (without the core the frequency will be higher than 108 MHz). Forgetting to write that the resistor value is 300 and 380 ohms, I ended up with 330 ohms. In the emitter, I think it’s not critical, but I’ll try to increase the axis of food. Well, I’ll play with the high-minded ones.
Before speaking, what is the function of the 120 pf capacitor, what is the connection to the base of the first transistor? What is the required voltage for the option with a line output, what is the signal required?

#30 Andriy Serpen 23 2015

Having picked up the transmission from the generator. The tension pleases -> = 30m from the walls. Harmonics are also marked (indicate on range statements). I'll check the frequency after it's too fast and then I'll push it. There are approximately three such frequencies (shock on the line) in the range 64-108 MHz (the highest and most likely was lower than stated in the frequency description). Trying to rotate the capacitors and resistors, placing the generator near a box with or without metal soldered to minus (screen). The harmonics are lost. There are no parts near the coil, except for the sub-condenser. Live 10V battery (if you want with a simple stabilizer, but the background is strong) if you want a little bit of battery power if there is a hemline cord nearby. The input capacitor is 0.33 microns mica. The 2k resistor is turned up (as a line input). Installation on a board with cut tracks (the gap between them is approximately 0.5 mm.) What are your recommendations?

#31 novel November 14, 2015

good schematic, can anyone send me the board and details?

#32 andr Berezen 01 2016

By soldering on the prototype of the transmissions on the first two stages of this circuit.
More precisely, the circuit of the first cascade (oscillator) is taken as a variant of the line input, and not for the microphone. All the values ​​of the elements may be slightly different. Ale is not the point.
The first cascade has 2n3904. Having mastered yoga for the first time. The best way to reach it is to sing in 1-2 steps. Live stream 8 mA.
Then we installed and adjusted another cascade, the KT603B transistor. The reception began to sing throughout the entire apartment (through 4 walls).
And now food. The circuit supply was 150mA (with a base resistor of 90kOhm), powered by a 12V battery. This is 1.8W pressure. I miraculously reveal that there is also 1.8 watts of tension and intelligence, and that KT603 will boil and die. Ale tse does not come out. The temperature in Newogo is close to 40C. Nutrition: is most of the effort going to the bathroom? It turns out that my transmission intensity is in the region of 1-1.5W? There seems to be a lot to offer for such a simple scheme.
Without checking the range, because... only required between the apartments.
And also other nutrition: how to select the optimal antenna voltage? I tried cutting from 15 cm to 1 m and noted that the transistor was heating up a little.

#33 root Berezen 01 2016

For manual adjustment, you can download the hvilemir scheme. Bring the hvilemiru antenna to a small distance from the radio transmission antenna and adjust the P-circuit of the transmission or the device for the antenna, achieving maximum values ​​in the hvilemiru readings.
In the diagram (Fig. 1), the setup with the antenna is based on an additional capacitor, which is connected to the coils L7, L8, as well as by changing the connection between the turns of these coils.
The transmission cannot be switched on without voltage (antenna or equivalent) - the output transistor may burn out.
In your case, the situation is entirely pleasant; in any case, you can install a small radiator on the transistor. The tension is generated by the circuit and is not the same as the tension, which is applied to the antenna, which takes into account heating costs, the mode of operation of the transistor, the type of antenna, etc.

#34 andr Berezen 01 2016

Thank you for your confirmation! Why replace KD510 KD522? Or better yet, look for 1n4148?
About the heat - well, I figured that if the heater is 1.8 W, and the single heater element heats up weakly, then most of it (1-1.5 W) goes to the heat exchanger, because There is nothing more to bask there, but you need to go somewhere. Before speaking, the body of the KT603 is based on the old MPshek, so the radiator needs to be soldered together.
Also food. In most cases, as an antenna, install a length of coaxial beam. Why? I'm picking up some simple wires - what's the smell of wires?

#35 POPS Berezen 07 2016

Can you tell me how critical is the capacitance of the split capacitor in the base of another transistor, which is 120pf in the circuit it is designed with?
Should I set the volume to 1nf or set it to 10nf, which will make the sound clearer? otherwise it’s some kind of wood

#36 Oleksiy Sichen 06 2017

Can the microphone be replaced at km 70??????, what about the Chinese polar?

#37 root Sichen 06 2017

You can use either an electric or condenser microphone (with a built-in boost transistor). The Chinese polar tape recorder is also an electric microphone.

#38 Oleksandr Compromister Zhovten 09 2017

I came up with an idea for the first circuit: to combine transistors VT1 and VT2 into one transistor assembly 1HT591. And tighten the cascade additionally on the same KT610, so that the butt does not crack across due to the strain.

#39 Oleksandr Kompromister Zhovten 09 2017

Re: #25 Andriy Berezen 10 2015 Try to create a scheme [Shustov M.A. Practical circuit design: 450 colorful circuits for radio amators: Book 1. Altex-A: Moscow, 2001. – P.125. Malyunok 13.11], or [ibid. - P.128. Figure 13.16] for video broadcasting. Report: [f. Radio. 10/96-19] that [f. Radio amator. 3/99-8] obviously.

#40 Danilo Sichen 17 2019

Hello, I’ll ask you again for better food. How can I replace KT610? Can I put the kt9180 in it and it will be tighter?

#41 root Sichen 17 2019

Danilo, the comments already provided food like this. KT9180 has a limiting frequency of the transmission coefficient of the stream of approximately 100 MHz, which is suitable for this circuit.

#42 Danilo Lyutiy 05 2019

I tell you, I was not surprised at the frequency of the kt9180 and immediately refused to cancel the confirmation. Ale, I can still ask:
1. What to do with the earth, I previously thought that the earth = -, but after googling, I realized what’s wrong. I read here in the comments that the land needs to be added to the building for film adaptation. I'm starting to get confused.
2. the same power supply for the KT610 drive, can it be replaced with the BFG135? Tse NHF n-p-n SMD. If so, then why would you have to mount it on a radiator?
3. In the comments, you wanted to use the audio input to select 1 cascade for this circuit and here I have no power supply - how to connect it to this circuit? Thank you very much for your concern and respect.

#43 root Lyutiy 06 2019

Installation of this circuit is best done immediately by securing the entire screen and sub-parts with partitions to screen. You can pick up the diagram on the “heels” following the method of S. Zhutyaev, describe the application from the photo and from the articles and comments before them:

• Design of amateur UHF radio station on the range 144 MHz, 430 MHz, 1200 MHz
• Scheme of the VHF receiver for direct conversion of the 144 MHz range

With this installation, all connections are mounted on the heels and mounted overhead. A lining made of foil, which has lost its insulation from the spots, is added to the minus of the circuit, serves as a screen, and before it the main components are connected, which must go to the minus, as well as the partitions between cascades. This is foiled on top of the laminated textile and the screen will be the ground of the circuit.

Installation of transmission with cascade screens by partitions:

Schodo BFG135 is a high-frequency SMD transistor (up to 7000 MHz) with a 150 mA collector flow. You can try using it at the output stage, otherwise you need a radiator.

The lining of the transistor is a collector, and on the circuit the emitter goes to minus, so it is not possible to solder it to the foil. Alternatively, you can connect the semi-circuit plate under the collector on the board and then solder the transistor pad there - through it, heat is transferred to the other board.

To use a different generator circuit, it is enough to connect coil L1 to coil L2, which is connected to the HF tension amplification cascades:

These programs will be very easy to produce, especially for radio amateurs. Please note on the module purchased from AliExpress, on EM9809.

Many of us have a couple of FM radios, not to mention those that even in any mobile phone, smartphone or tablet have the ability to receive FM. However, it’s never been a while before you play your favorite music on the radio, and in my opinion, they never played it.

This device will help you organize broadcasting in the range of 76 to 110 megahertz at a distance of 5 to 30 meters!

Do-it-yourself listening at 500 meters

A radio bug with your own hands can transmit sound up to 500 meters away. Also, with the help of this, you can create an FM tuner and transmit the signal from the phone to the radio.

Radio broadcast on kt368

Do-it-yourself radio broadcast on KT368

From this article I would like to inform you about radio transmission on a single transistor.

You can use it for listening, or use an additional repeater, replacing the microphone, for the audio signal input.

DIY radio transmission on MC2833

DIY radio transmission on MC2833

Using the MC2833 microcircuit, you can get clear FM transmission. This microcircuit contains a generator, HF booster, sound booster and modulator. Available options include a miniature plastic housing with end caps for surface mounting and a standard housing.

FM transmission with your own hands for 1 km and more

Do-it-yourself FM transmission for 1 km

It is necessary to obtain a powerful 2 W FM transmission, which can provide up to 10 km of range, naturally with a well-adjusted high-quality antenna and in good weather conditions without any problems. The scheme was found in the bourgeoisie and it turned out to be complete and original, so that it could be presented to your court))

DIY stereo radio transmission circuit

Transmitting a stereo radio signal with your own hands

In a car, if it is not possible to turn on music from other devices like a radio, and if you want to hear something other than what the radio presenters say, you can choose your own music as an option. DIY FM stereo transmission .

Radio transmission of meetings in a standard plastic case and any accessory. The front panel has a Jack type audio input and a setup button. On the back surface there is a rose of life. The filter connects to the +12V terminal, so the power cable is used as an antenna. The board is designed to be secured with just one screw in the middle of the box.

Audio broadcast

DIY audio transmission (music transmission)

I want to understand this statistic music broadcaster. I tried to pick up radio transmissions from wireless stations using a varicap modulator. Some wires are required to transmit the sound signal, and if not, replace the microphone with a plug. Coil 9 turns dart with a diameter of 1 mm, middle solder connection. In the middle of the coil, put a small piece of foam rubber and drip it with paraffin (candle), so that the coil does not bend when touched, so that the frequency can be stored, and it is very easy to break.

Do-it-yourself stereo transmission diagram

Radio-stereo sound transmission circuit

For stereo broadcasts specialized microcircuit, BA1404.Proproperty transfer to BA1404є high brilliance of sound and shortening of the stereo sound level. This is achieved by using a quartz resonator at 38 kHz, which provides the frequency of the pilot tone for the encoder to the stereo signal.

Stereo transmission can be stuck either in everyday life or in a car, for transmitting sound from a wearable device (phone, player, etc.), so it may not transmit stereo sound.

Such a small stereo transmission would be a bad replacement for an FM tuner.

DIY FM transmission

FM radio broadcast

UKH-FM radio transmission with your own hands, operates in the non-traditional range of 175-190 MHz. This radio microphone is awkward when folded. By increasing the frequency stability of the generator, which sets, the base circuit of the voltage booster transistor is powered by a voltage stabilizer (R5, LED1).

Stacking SMD RED LED The frequency range when “sitting” the life from 3 to 2.2 volts becomes no more than 100 KHz. When you turn the antenna by hand, the frequency increases slightly. If you are using a fire-powered nuclear submarine, this change is necessary and frequency monitoring during robotic transmission is not required.

Do-it-yourself radio transmission at 500 meters

Do-it-yourself radio microphone for 500 meters

I want to see the design is sufficient pushing radio bug, Range of action what it adds up to 500 meters with direct visibility. The device was collected as much as possible for consumption. showing beetle different results: The frequency of Mayzhe is not floating (through the leather 100 meters of the VSO for 0.1-0.3 mHz) not reacting to the Topkannya Anteni of the same unit (KRIM contour that frequency-and-in-law LANTSYUGA)-T-Dusty Vazhelivia moment, okіlka Maya The Internet faces this problem. Change the size of the bug many times, the radio bug is so small that it can fit in one cigarette, lighter, or mobile phone. Not a lot about parameters: frequency range between 88-108 megahertz microphone sensitivity close to 5 meters, in the quiet room there is a faint clicking of the wall anniversary. So this signal can be easily received from this bug on a radio receiver, be it on a telephone or just a landline one. Let's move on to the diagram and details.