A selection of diagrams and designs of homemade bug detectors for searching for radio bookmarks. Typically, radio eavesdropping circuits operate at frequencies in the range of 30...500 MHz and have a very low transmitter power of about 5 mW. Sometimes, the bug operates in standby mode and is activated only when noise appears in the controlled room.
This article discusses a bug detector circuit for searching for listening devices. The bug detector circuit is usually a bridge high-frequency voltage detector that operates over a huge frequency range.
Bug detector. Simple voltage detector circuit |
This simple circuit perfectly catches radio bugs, but only in the frequency range up to 500 MHz, which is a significant disadvantage. The tension detector antenna is made of a half-meter-long pin with a diameter of no more than 5 mm and insulated on the outside. Next, the signal is detected by a germanium diode VD1 and amplified by transistors VT1, VT2). The amplified UPT signal passes to a threshold device (DD1.1) and a sound generator made on elements DD1.2 - DD1.4, which is loaded onto a piezo emitter. As inductance L1, a low-frequency choke on a 2000NM ferrite ring is used, containing 200 turns of PEL 0.1 wire.
Another simple homemade device for searching for radio bookmarks is shown in the diagram in the figure just above. This is a broadband high-frequency voltage bridge detector operating in the range from 1...200 MHz and makes it possible to find “bugs” at a distance of 0.5 to 1 m.
To increase sensitivity, a proven method of measuring small alternating voltages using a balanced diode-resistive bridge is used.
Diodes VD5, VD6 are designed to provide thermal stabilization of the circuit. Three-level comparators made on elements D1.2...D1.4 and LEDs are connected to their outputs, which are used as an indicator. Diodes VD1, VD2 are used as a 1.4 volt voltage stabilizer. Operating the device is not very easy and requires practical skills, since the circuit can react to some household appliances, televisions and computers.
In order to simplify the process of identifying radio tags, you can use replaceable antennas of different lengths, which will change the sensitivity of the circuit
When you turn on the device for the first time, you need to use resistor R2 to make LED HL3 glow. This will be the initial sensitivity level relative to the background. Then, if we bring the antenna closer to the radio signal source, other LEDs should light up depending on the amplitude level of the radio signal.
Resistor R9 adjusts the threshold sensitivity level of the comparators. The circuit is powered by a nine-volt battery until it discharges to 6 volts
Resistors R2 can be taken SPZ-36 or other multi-turn, R9 SPZ-19a, the rest are any; capacitors C1...C4 K10-17;.
You can also use any LEDs, but with low current consumption. The design of the circuit depends only on your imagination
During operation, any radio bug emits radio waves, which are detected by the detector antenna and enter the base of the first transistor through a high-frequency filter, which is made on capacitors C1, C2 and resistance R1.
The filtered signal is amplified by bipolar transistor VT1 and goes through capacitor C5 to the high-frequency first diode. Variable resistance R11 regulates the proportion of the signal on the diode entering the operational amplifier DD1.3. It has a high gain, which is set by C9, R13, R17.
If there is no signal from the radio tags at the antenna, then the signal level at the first output of the op-amp DD1.3 tends to zero. When radio emission occurs, the amplified signal from this output will go to a voltage-controlled audio frequency generator assembled on elements DD1.2., DD1.4 of the MC3403P microcircuit and the third transistor. From the output of the generator, the pulses are amplified by a second transistor and sent to the speaker.
Bug detector with ten LEDs |
The basis of the electromagnetic field detector is the LM3914 microcircuit, which has ten comparators internally and, accordingly, the same number of outputs for connecting LEDs. One of the outputs of each comparator is connected to the input through a signal amplifier, the other output is connected to a resistive divider at the point corresponding to the specified indication level.
The beginning and end of the resistive divider are connected to pins 4 and 6. The fourth is connected to the negative pole of the source in order to provide a voltage indication from zero. The sixth is connected to the 1.25 volt reference output. This connection means that the first LED will light up at a voltage level of 1.25 volts. Thus, the pitch between LEDs will be 0.125.
The circuit operates in the “Point” mode, that is, a certain voltage level corresponds to the glow of one LED. If this contact is connected to the positive of the power source, then the indication will be in the “Column” mode, the LED at the specified level will light up and everything below. By changing the value of R1 you can adjust the sensitivity of the detector. You can use a piece of copper wire as an antenna.
I was very surprised when my simple homemade detector-indicator went off scale next to a working microwave oven in our work canteen. It’s all shielded, maybe there’s some kind of malfunction? I decided to check out my new stove; it had hardly been used. The indicator also deviated to the full scale!
I assemble such a simple indicator in a short time every time I go to field tests of transmitting and receiving equipment. It helps a lot in the work, you don’t have to carry a lot of devices with you, it’s always easy to check the functionality of the transmitter with a simple homemade product (where the antenna connector is not fully screwed in, or you forgot to turn on the power). Customers really like this style of retro indicator and have to leave it as a gift.
The advantage is the simplicity of the design and the lack of power. Eternal device.
It’s easy to do, much easier than exactly the same “” medium wave range. Instead of a network extension cord (inductor) - a piece of copper wire; by analogy, you can have several wires in parallel, it won’t be any worse. The wire itself in the form of a circle 17 cm long, at least 0.5 mm thick (for greater flexibility I use three such wires) is both an oscillating circuit at the bottom and a loop antenna for the upper part of the range, which ranges from 900 to 2450 MHz (I did not check the performance above ). It is possible to use a more complex directional antenna and input matching, but such a deviation would not correspond to the title of the topic. A variable, built-in or just a capacitor (aka a basin) is not needed, for a microwave there are two connections next to each other, already a capacitor.
There is no need to look for a germanium diode; it will be replaced by a PIN diode HSMP: 3880, 3802, 3810, 3812, etc., or HSHS 2812 (I used it). If you want to move above the frequency of the microwave oven (2450 MHz), choose diodes with a lower capacitance (0.2 pF), HSMP -3860 - 3864 diodes may be suitable. When installing, do not overheat. It is necessary to solder spot-quickly, in 1 second.
Instead of high-impedance headphones there is a dial indicator. The magnetoelectric system has the advantage of inertia. The filter capacitor (0.1 µF) helps the needle move smoothly. The higher the indicator resistance, the more sensitive the field meter (the resistance of my indicators ranges from 0.5 to 1.75 kOhm). The information contained in a deviating or twitching arrow has a magical effect on those present.
Such a field indicator, installed next to the head of a person talking on a mobile phone, will first cause amazement on the face, perhaps bring the person back to reality, and save him from possible diseases.
If you still have strength and health, be sure to point your mouse at one of these articles.
Instead of a pointer device, you can use a tester that will measure DC voltage at the most sensitive limit.
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| Microwave indicator circuit with LED. |
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| Microwave indicator with LED. |
Tried it LED as indicator. This design can be designed in the form of a keychain using a flat 3-volt battery, or inserted into an empty mobile phone case. The standby current of the device is 0.25 mA, the operating current directly depends on the brightness of the LED and will be about 5 mA. The voltage rectified by the diode is amplified by the operational amplifier, accumulated on the capacitor and opens the switching device on the transistor, which turns on the LED.
If the dial indicator without a battery deviated within a radius of 0.5 - 1 meter, then the color music on the diode moved up to 5 meters, both from the cell phone and from the microwave oven. I was not mistaken about color music, see for yourself that the maximum power will only be when talking on a mobile phone and in the presence of extraneous loud noise.
Adjustment.
I collected several such indicators, and they worked immediately. But there are still nuances. When turned on, the voltage on all pins of the microcircuit, except the fifth, should be equal to 0. If this condition is not met, connect the first pin of the microcircuit through a 39 kOhm resistor to minus (ground). It happens that the configuration of microwave diodes in the assembly does not coincide with the drawing, so you need to adhere to the electrical diagram, and before installation I would advise you to ring the diodes to ensure their compliance.
For ease of use, you can worsen the sensitivity by reducing the 1 mOhm resistor, or reducing the length of the wire turn. With the given field values, microwave base telephone stations can be sensed within a radius of 50 - 100 m.
With such an indicator, you can draw up an environmental map of your area and highlight places where you can’t hang out with strollers or stay with children for a long time.
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Be under base station antennas |
Analog level indicator.
I decided to try to make the microwave indicator a little more complex, for which I added an analog level meter to it. For convenience, I used the same element base. The circuit shows three DC operational amplifiers with different gains. In the layout, I settled on 3 stages, although you can plan a 4th one using the LMV 824 microcircuit (4th op-amp in one package). Having used power from 3, (3.7 telephone battery) and 4.5 volts, I came to the conclusion that it is possible to do without a key stage on a transistor. Thus, we got one microcircuit, a microwave diode and 4 LEDs. Taking into account the conditions of strong electromagnetic fields in which the indicator will operate, I used blocking and filtering capacitors for all inputs, feedback circuits and op-amp power supply.
Adjustment.
When turned on, the voltage on all pins of the microcircuit, except the fifth, should be equal to 0. If this condition is not met, connect the first pin of the microcircuit through a 39 kOhm resistor to minus (ground). It happens that the configuration of microwave diodes in the assembly does not coincide with the drawing, so you need to adhere to the electrical diagram, and before installation I would advise you to ring the diodes to ensure their compliance.
This prototype has already been tested.
The interval from 3 illuminated LEDs to completely extinguished ones is about 20 dB.
Power supply from 3 to 4.5 volts. Standby current from 0.65 to 0.75 mA. The operating current when the 1st LED lights up is from 3 to 5 mA.
This microwave field indicator on a chip with a 4th op amp was assembled by Nikolai.
Here is his diagram.
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| Dimensions and pin markings of the LMV824 microcircuit. |
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| Installation of microwave indicator on the LMV824 chip. |
The MC 33174D microcircuit, which has similar parameters and includes four operational amplifiers, is housed in a dip package and is larger in size and therefore more convenient for amateur radio installation. The electrical configuration of the pins completely coincides with the L MV 824 microcircuit. Using the MC 33174D microcircuit, I made a layout of a microwave indicator with four LEDs. A 9.1 kOhm resistor and a 0.1 μF capacitor in parallel with it are added between pins 6 and 7 of the microcircuit. The seventh pin of the microcircuit is connected through a 680 Ohm resistor to the 4th LED. The standard size of the parts is 06 03. The breadboard is powered by a lithium cell of 3.3 - 4.2 volts.
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| Indicator on the MC33174 chip. |
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| Reverse side. |
The original design of the economical field indicator is a souvenir made in China. This inexpensive toy contains: a radio, a clock with a date, a thermometer and, finally, a field indicator. The unframed, flooded microcircuit consumes negligibly little energy, since it operates in a timing mode; it reacts to turning on a mobile phone from a distance of 1 meter, simulating a few seconds of LED indication of an emergency alarm with headlights. Such circuits are implemented on programmable microprocessors with a minimum number of parts.
Addition to comments.
Selective field meters for the amateur band 430 - 440 MHz
and for the PMR band (446 MHz).
Indicators of microwave fields for amateur bands from 430 to 446 MHz can be made selective by adding an additional circuit L to SK, where L to is a turn of wire with a diameter of 0.5 mm and a length of 3 cm, and SK is a trimming capacitor with a nominal value of 2 - 6 pF . The turn of wire itself, as an option, can be made in the form of a 3-turn coil, with a pitch wound on a mandrel with a diameter of 2 mm with the same wire. An antenna in the form of a piece of wire 17 cm long must be connected to the circuit through a 3.3 pF coupling capacitor.
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| Range 430 - 446 MHz. Instead of a turn, there is a step-wound coil. |
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| Diagram for ranges 430 - 446 MHz. |
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| Frequency range mounting 430 - 446 MHz. |
By the way, if you are serious about microwave measurements of individual frequencies, you can use selective SAW filters instead of a circuit. In the capital's radio stores their assortment is currently more than sufficient. You will need to add an RF transformer to the circuit after the filter.
But this is another topic that does not correspond to the title of the post.
Ultrahigh frequency (UHF) radiation or so-called microwave radiation has an adverse effect on the human body. To protect yourself and your loved ones from the consequences of this type of radiation, detectors of varying complexity are used to detect the leakage of radiation from microwave ovens, cell phones and other devices. How to identify a dangerous device — We’ll talk about this in this article.
Photo. 1. Appearance of a Panasonic household microwave oven
Not everything that is written in the instruction manual for household appliances (especially translated manuals) is true. Most often, this is a so-called half-truth: on one side everything seems to be true, but it often turns out that something is left unsaid. The same applies to phenomena and processes that can be dangerous to the life and health of a person or his things.
Not so long ago, the time has passed (or maybe not yet) when portable household dosimeters were extremely popular among the population. No, of course, not every family had a nuclear reactor in their apartment or country house, but the products and things they bought secondhand and in markets clearly required control. No, no, and the dosimeter went off scale... For the same reason, today people buy devices to measure the level of pesticides in various fruits of nature.
One of the sources of adverse effects on the human body is ultrahigh frequency (UHF) radiation or so-called microwave radiation. A striking example of an electronic device with a microwave radiation generator (magnetron) is a microwave oven (see Fig. 1).
In addition to potentially dangerous microwave radiation for humans and animals, a microwave oven (hereinafter referred to as the oven) creates strong electromagnetic radiation, which has a negative effect on some objects and things - for example, wristwatches with an electromagnetic system (and others).
Photo. 2. Panasonic microwave oven with the housing cover removed
Generally, a new oven will operate reliably and will not emit harmful radiation outside its housing, but it is still best to avoid placing watches, cell phones, or other items on it.
A furnace that was repaired outside a service center, in which the main element of the generator was replaced - the magnetron, with a damaged housing or has damage to the working chamber, waveguide and other deficiencies, is potentially hazardous to health.
To identify such harmful ovens and other devices (for example, a broken mobile phone), microwave radiation indicators are used. The simplest diagram of such an indicator is shown in photo 3.
Photo 3. A simple microwave radiation indicator circuit that you can assemble yourself
Note to photo 3. A loop is a piece of copper wire with a diameter of 1...1.5 mm. Electric spot welding wire is quite suitable for this purpose. Microwave diode - diode type 2A202A, DK-V8 or similar. The tester is a milliammeter with a full needle deflection current of 100 µA. In our case, it is better to use a pointer device, for example, Ts4342, Ts4317 or similar. Non-polar capacitor - any, for example, MBM type.
The junction of the magnetron with the power source contains transition capacitors, which (together with the chokes) form a filter to protect against the penetration of microwave radiation from the magnetron and the waveguide to the outside.
The principle of checking a microwave oven is simple - a “loop” with a microammeter is slowly passed next to the body of the microwave oven (at a distance of 1-6 cm from it). A slow “scanning” speed is needed in order to capture microwave radiation in the most dangerous area of the oven.
The microwave radiation generator is turned on in the oven during cooking not constantly, but periodically. This is also noticeable visually: the backlight inside the oven’s working chamber dims a little, and the oven makes a little more noise when the generator is turned on.
What don't we know about the magnetron?
The most important component of a microwave oven is a magnetron, which is an electric vacuum diode designed to generate microwave oscillations. When the magnetron operates, power is released, which turns into heat, so a thermal electromagnetic field is created inside the working chamber. The power generated by the magnetron is supplied through a waveguide - a device that transmits energy to the working area of the furnace, which is a rectangular chamber (working chamber).
Photo 4. Close-up of the magnetron
Next to the waveguide output there is a rotating table on which the product to be processed is placed. All this is located inside the furnace body.
It is important that the radiation (hazardous to life if directly exposed to a person) does not extend beyond the furnace body. The furnace body is a closed metal structure, which at the same time serves as a screen for microwave radiation.
For household heat treatment in the microwave wave range, electromagnetic oscillations are used at frequencies of 2375, 2450 MHz - in very old models, and up to 10-12 GHz in modern ovens. In table 1 provides information on the depth of penetration of an electromagnetic wave (with energy losses) into some of the dielectrics.
Table 1. Penetration depth of an electromagnetic wave in a dielectric with losses at a temperature of 20-25 ºС
Modern magnetrons (magnetrons with a non-heated field cathode type MI and similar) provide “instant” (from the first pulse) readiness to operate at full power without wasting energy on heating the cathode, which significantly increases the reliability of the magnetron.
The use of a heatless magnetron made it possible to simplify the electrical circuit of the furnace, eliminating dozens of radio components. In this regard, there is no need for a transformer, a control device and a voltage regulator in the magnetron filament circuit (since there is no filament itself), master and blocking generators, it was possible to reduce the weight and dimensions of the furnace, reduce the cost of the product, while simultaneously increasing its operational reliability.
Possible malfunctions of magnetrons:
The anode of the magnetron is made in the form of a copper cylinder. The operating voltage of the magnetron anode (depending on the type) ranges from 3800 to 4000 V. Power from 500 to 1200 W. The magnetron is mounted directly on the waveguide (Fig. 3). In furnaces where the manufacturer places a magnetron with a short waveguide, a defect such as breakdown of the mica gasket can be observed. This happens as a result of contamination of the gasket;
when the gasket breaks down, the magnetron cap melts (this happens with magnetrons of the type 2M-218N(R), OM7S(20), 2M213-09F, 2M-219N(V), 2M226-09F and structurally similar). It (the cap) can be replaced with a similar cap from another magnetron;
Like any lamp, it can lose its emission, resulting in a significant reduction in energy output and an increase in cooking time. Typically, the average service life of a magnetron (for example, 2M213-xx) has a limit of 15,000 hours. Its efficiency is 75-80%, which is an effective indicator for magnetrons of microwave oscillation generators;
breakdown of transition capacitors can be detected using a tester in resistance measurement mode. The breakdown occurs on the magnetron housing. The malfunction is eliminated by replacing the entire assembly.
Separately, the magnetron can be checked only by generating all the voltages necessary for its operation.
Photo 5. Microwave oven power supply
In a microwave oven, the second most important element after the magnetron is the power supply (Photo 5). The entire safe operation of the furnace depends on its reliability.
A wonderful tool for repairing and diagnosing microwave ovens, in particular when diagnosing magnetrons, are current clamps, for example, ECT-650 “Escort”.
They allow you to measure the current consumed by the furnace, the current of the high-voltage winding of the transformer. The rated current consumed by the furnace is 4.5 - 6 A, the current of the high-voltage winding of the transformer is 0.3 - 0.5 A.
Large deviations from the specified values (especially in the direction of increasing individual parameters) indicate a local malfunction of the magnetron.
At the same time, an underestimation of all parameters can be explained by poor contacts, starting from the power outlet and ending with switching elements (relays, electrical microswitches, contacts).
In order to make sure that the magnetron is working properly and that there is a sufficient level of microwave radiation inside the furnace body, it is checked with a detector.
Microwave Radiation Detectors
Photo 6 shows an industrial microwave radiation detector, which can be purchased at electrical goods stores.
Rice. 6. Microwave radiation detector
This device detects only microwave pulses, which can be checked by bringing the device directly to its walls while the oven is operating. It will also be useful for searching for “bugs” operating at ultra-high frequencies, searching for cell phones and checking their operation. Such an industrial tester costs less than 500 rubles.
The device is powered by a 6F22 Krona battery with a voltage of 9 V. The current consumption of the device in standby mode is a few μA, so the battery lasts a long time. An indicator LED is located at the top of the case.
It will light up when microwave radiation is present in the detector area (shown on the body by an arrow). The device does not measure radiation power, but records its presence.
Using such a detector, you can check not only the working chambers of microwave ovens and the presence of harmful radiation outside their housing, but also the presence of radiation from cell phones. It's easy to do.
It is necessary to bring the detector to a possible source of radiation, for example, to the body of a mobile phone at a distance of 2-10 cm. When the cell phone is active: during an incoming and outgoing call, unauthorized “communication” of the cell phone with the base station, when registering the cell phone on the network (for example, when turning on the cell phone) and in other cases - the detector indicator will show the presence of microwave radiation.
It would be a good idea to use this visual lesson in physics lessons in schools, so that people understand how harmful or useful it is to constantly carry a cell phone close to your own body (on your chest, on your belt, in your pocket, especially your chest).
The results of harmful microwave radiation (especially with constant exposure) are probably better commented on by scientists and medical professionals. On my own behalf, I will only add that microwave radiation is like an atom, which can be peaceful or not. This must be clearly understood when using a seemingly harmless mobile phone or microwave oven.
Another industrial device intended for motorists, called a “spark indicator,” can also be used as a microwave radiation detector. Such devices are commercially available, one of which is shown in Fig. 7.
Rice. 7. Photo (appearance) of the microwave radiation detector — spark indicator
The device is designed to test high-voltage ignition circuits of cars. A sensor is installed inside the case (the same loop as in the diagram in Fig. 5, only in miniature), which, as practice has shown, responds not only to high pulse voltage in the ignition of a car, but also to microwave radiation from a microwave oven and a cell phone.
A red LED located near the “high voltage” arrow also serves as an indicator of microwave radiation.
On remote wires, the indicator is powered from any power source with a constant voltage of 8-15 V, including a Krona battery or a car battery.
The peculiarity of the device is that it has sensitivity adjustment (the adjustment knob is located on the top of the body). Such a device costs around 300 rubles. Having it, you no longer have to worry about other microwave radiation detectors.
Safe work measures during repair and maintenance of microwave ovens
Failure to comply with these rules can lead to electric shock, injury and failure of quite expensive components of the microwave installation.The most dangerous (of all available in domestic conditions) for humans is alternating current with a frequency of 50 Hz, as well as microwave radiation.
A microwave oven connected to a 220 V network (under voltage) can be repaired and checked only in cases where it is impossible to perform work in a device disconnected from the network (setup, adjustment, measuring modes, searching for bad contacts in the form of “cold soldering” and similar cases).
Care must be taken to avoid exposure to dangerous voltage.Avoid burns from heating elements.
In all cases of working with the oven turned on, it is necessary to use tools with insulated handles. You should work with one hand, wearing long sleeves or oversleeves.
At this time, you must not touch the stove body or other grounded objects (central heating pipes, water supply) with your other hand. Wires of measuring instruments must end with probes and have good insulation.
These are general electrical safety rules.
Attention, dangerous:
soldering of furnace elements under voltage;
repair a stove that is connected to the electrical network, in a damp room, or with a cement or other conductive floor;
is located near the installation by persons not repairing it;
Like any source of microwave radiation, direct exposure to magnetron radiation can cause eye damage or skin burns. The human eye cannot see microwave radiation;
When replacing the magnetron, be especially careful. Do not leave installation debris in the waveguide;
Before replacing, always dilute the capacitor in the magnetron power supply circuit with a piece of insulated wire (the shunt resistor sometimes fails).
In addition, when operating the stove it is not allowed:
turn on the oven with the door or screen open (it will not turn on itself, since there is protection for that, but this point is relevant for those who neglect this protection by turning it off);
you can’t make holes in the body (housewives who dream of hanging the stove on the wall like a bread box, let such thoughts be abandoned).
From short distances. Naturally, I immediately wanted to make a similar homemade product, since it is quite impressive and demonstrates in practice the work of electromagnetic pulses. The first models of the EMR emitter had several high-capacity capacitors from disposable cameras, but this design does not work very well due to the long “recharging” time. So I decided to take a Chinese high voltage module (commonly used in stun guns) and add a "punch" to it. This design suited me. But unfortunately, my high-voltage module burned out and therefore I could not film an article on this homemade product, but I had a detailed video on the assembly, so I decided to take some points from the video, I hope the Admin will not mind, since the homemade product is really very interesting.
I would like to say that all this was done as an experiment!
And so for the EMR emitter we need:
-high voltage module
-two 1.5 volt batteries
-box for batteries
-body, I use a 0.5 plastic bottle
-copper wire with a diameter of 0.5-1.5 mm
-button without lock
-wires
The tools we need are:
-soldering iron
-thermo glue
And so, the first thing you need to do is wind a thick wire of about 10-15 turns around the top of the bottle, turn to turn (the coil greatly affects the range of the electromagnetic pulse; a spiral coil with a diameter of 4.5 cm has shown to work best) then cut off the bottom of the bottle
We take our high-voltage module and solder the power supply through the button to the input wires, after first removing the batteries from the box
Take the tube from the handle and cut off a piece 2 cm long from it:
We insert one of the high-voltage output wires into a piece of tube and glue it as shown in the photo:
Using a soldering iron, we make a hole in the side of the bottle, slightly larger than the diameter of the thick wire:
We insert the longest wire through the hole inside the bottle:
Solder the remaining high-voltage wire to it:
We place the high-voltage module inside the bottle:
We make another hole on the side of the bottle, with a diameter slightly larger than the diameter of the tube from the handle:
We pull out a piece of tube with a wire through the hole and firmly glue it and insulate it with thermal glue:
Then we take the second wire from the coil and insert it inside a piece of tube, there should be an air gap between them, 1.5-2 cm, you need to select it experimentally
we put all the electronics inside the bottle, so that nothing shorts out, does not dangle and is well insulated, then glue it:
We make another hole along the diameter of the button and pull it out from the inside, then glue it:
We take the cut bottom and cut it along the edge so that it can fit onto the bottle, put it on and glue it:
OK it's all over Now! Our EMR emitter is ready, all that remains is to test it! To do this, we take an old calculator, remove valuable electronics and preferably put on rubber gloves, then press the button and bring the calculator up, electric current breakdowns will begin to occur in the tube, the coil will begin to emit an electromagnetic pulse and our calculator will first turn on itself, and then begin to randomly write numbers on its own !
Before this homemade product, I made an EMR based on a glove, but unfortunately I only shot a video of the tests; by the way, I went to an exhibition with this glove and took second place due to the fact that I showed the presentation poorly. The maximum range of the EMP glove was 20 cm. I hope this article was interesting to you, and be careful with high voltage!
Electromagnetic radiation is constantly around us, but it is inaccessible to human hearing. If you want to hear electromagnetic radiation, you can use a special device that we will make with our own hands.
To make an electromagnetic radiation detector we will need:
- old cassette player;
- glue;
The cassette player needs to be disassembled and the board removed from the case itself. It is recommended to familiarize yourself with the board not only for self-development, but also to ensure that no parts are broken when assembling and disassembling this device. This part is very sensitive to electromagnetic waves.
The most important part on the board is the read head, which will be useful to us later.
There are two wires near the read head, which are secured with bolts. These bolts will need to be unscrewed. After unscrewing the bolts, the reading head should remain, which will hang on the cable. You need to be extremely careful with it so as not to tear it off.
If the player does not have an external speaker, then we connect ordinary headphones to a special connector, which will help us hear electromagnetic waves.
Now we lean the read head against the TV. We can hear electromagnetic radiation. The radiation can be heard at a distance of up to 40 cm, the further we move away, the worse the sound will be heard. It is important to note that the old TV (cube) gives us a lot of radiation.
If we connect our device to a new generation of TVs (liquid crystal), we will also hear interference, but not so strong.
A big surprise was the fact that even the TV remote control emits electromagnetic radiation.
It's no secret that radiation also comes from the phone. When tested, the sound was similar to when you make a call and have your speakers turned on. The radiation comes from absolutely any phone, even the coolest and most sophisticated one, and you don’t have to dial the number, you can go online.
Even ordinary phone chargers and door handles emit electromagnetic radiation.
Using a regular player, you can hear radiation that is not heard by the ears and not seen by the eyes.