Today you and I, dear anonymous, will deal with heavy weapons, namely various Wi-Fi/3G/4G guns. Not long ago, this weapon appeared on YouTube thanks to famous video bloggers under the nickname KREOSAN. It was presented in the manner typical of this video blog as some kind of super-creative, so the anonymous person is tormented by vague doubts: can one believe in the authenticity of all this? Let's start looking for an answer to this question...
First of all, let us draw your attention to the fact that the very idea of this Wi-Fi gun was proposed by I. Panchenko on the forum lan23.ru back in 2007, but there is not a word about this either in the video or in the description. Not a good thing for the harsh creosans, is it, Karl?
True, it is worth noting that on the antenna page on lan23.ru In the description and in the picture below the sizes are completely different. Let’s say right away that both options work, but which one should you choose? Moreover, on the forum itself and on the Internet you can find up to 3-4 different size options. And in the Creosan video itself there is a drawing in which the reflector is made with a side, but in the video it is without a side, which again gives rise to some doubts. The option without a side was initially proposed by I. Panchenko, tested by him on a real link and brought to perfection on instruments, so to speak, in combat conditions. It is also implemented in the KREOSAN video. To understand all this, you need to carefully re-read the entire discussion on the forum. Imagine the cognitive dissonance of an anonymous person, 
who has little understanding of what the forum is all about (well, he’s not an expert in microwave antennas!) and for the first time found this description with incomprehensible dimensions. So thanks to KREOSAN for helping the anonymous person decide on the choice of option. When analyzing the model in HFSS, it is clearly visible that the antenna should be without a side. 
As we see, according to SWR< 2 антенна имеет очень широкую полосу пропускания. Это обуславливает ее неплохую повторяемость, что очень важно. Плюс к этому и другие существенные преимущества антенны, о чем пишет И.Панченко в описании. Антенна известна еще со времен исторического материализма и расово правильное ее название fin-rod antenna, but not a “gun” at all. You can see one of its variants in the photo of the Soviet lunar rover. Now the “new generation”, who do not remember the hoary old days, have given it the name Patch-Yagi. She has "hereditary" features from Uda-Yagi:
- an endless set of size options for given characteristics, in other words, searching for “actual”, “final” correct sizes does not make sense;
- with a large number of elements, repeatability decreases, i.e. it will not be possible to make a long “gun” with a large number of directors and a gain of 20 dBi or more without instrument tuning; it will work, but no better, and perhaps even worse, than a short one, in other words, making a “super gun” with a number of directors of more than 5 in artisanal conditions it does not make sense;
You can, of course, make some claims here, such as this set of sizes from I. Panchenko is not optimal, not ideal, not kosher, not Orthodox, etc., especially if the practical implementation of the gun did not work out. Where have you seen ideal antennas? The antenna is just very good, that's all. This is confirmed, by the way, by direct measurements: 
We present to your attention an online calculator of this gun for conversion to other frequencies. Schematic image of a 7-disc gun by I. Panchenko (or from the KREOSAN video): 
ENTER DATA:
Distances h0, h1...h5 in the model appear as distances from the beginning of one plate to the beginning of the next, if we take the back side of the reflector as the reference point and move in the direction of the last director. Thus, they are equivalent to the distance between the axes of the plates.
An anonymous person may wonder why on KREOSAN’s channel “3G/4G gun” has one less disk? We also don’t know why, what they were guided by and where they got the dimensions. There is a suspicion that they took as a basis the same “picture below” from the original source that we mentioned, scaled the dimensions and passed it off as their own. Their mistake is that in this design the edge is required, and if it is removed, the resonant frequency of the structure goes up. As a result, the “3G Kreosan gun” on the link has a central frequency above the operating range. By the way, the forum thread on lan23.ru has not dried out (see link) and this circumstance is discussed there. The conclusion from the discussion is that the 3G/4G gun from Kreosan shoots, but “crookedly”. Why do we need crooked guns? Should we waste time? That's it. Better to look at the broadband Batwing instead...
Calculation of the 7-disc gun (which we recommend for repetition) has been added to our Android application Cantennator. Tap on the QR code if you came here from a mobile or tablet, or scan this code with your mobile if you are viewing this page on a desktop monitor to go to Google Play to download. Don't forget to rate the app and leave a review. 
The manufacturing features and design of the antenna can be viewed in detail using the links below. Let us only note that the thickness of the plates can be changed within 0.3..1 mm (it is better to take a reflector as a supporting disk thicker, about 2 mm), and use studs no larger than M6. However, the likelihood of a negative result will be much less if you abandon the studs and solder the disks onto a steel or brass pin with a diameter of 2-3 mm (for example, onto a welding electrode as in the original assembly). In fact, the use of studs with nuts is not an invention of video bloggers, but was used much earlier. At least look at the article by the “ushkuinik” at the link. It’s just convenient to use nuts to adjust a ready-made antenna according to instruments (see the picture above, where a gun with nuts is connected to an impedance meter). If you do not have instruments, it is better to refuse studs and nuts and follow the original article (link).
We are responding to numerous requests to recalculate the 75 Ohm antenna. There is no need to recalculate the dimensions; the 7-disc “gun” works with equal success both on a 50-ohm load and on a 75-ohm load. Below is a graph of the Wi-Fi SWR of a 7-disk “gun”, calculated for the Wi-Fi range, powered by an RG213 cable with a load of 50 Ohms and powered by an RG6 cable with a load of 75 Ohms with the “correct” connection. As you can see, within the operating range, the SWR with both loads does not exceed two. At the beginning of the article there is a graph of the SWR of this antenna, connected via connector to a 50 ohm load. 
High-speed Internet in the modern world is an integral part of human life. It is known that connection to the World Wide Web on a computer occurs through a modem, which is divided into landline and wireless. If this is cable equipment, everything is quite simple and the speed is high. If you use a portable modem (2G, 3G or 4G), it is not always possible to get a high-quality high-speed connection. And here a banal antenna can come to the rescue.
Instructions for making an antenna for a 4G modem yourself.
You shouldn't immediately rush and buy an industrially manufactured amplifier. It is quite expensive and does not fit every modem, as it requires a built-in connector or an additional adapter, which is comparable in cost to the 3G or 4G router itself. And then, naturally, the question arises of how to make an antenna for a modem with your own hands, without having certain skills.
Before you look at how to make your own amplifier, you should know the reasons for a poor Internet connection, on which the quality of communication largely depends.
- Normal network overload.
- A long distance from the modem to the provider's station.
- Finding a 4G device in a certain part of the house.
- Obstacles between the router and the dispenser.
How can you increase the router signal?
If you purchased a 4G modem, for example, Megafon, to replace an old router, and the declared speed remains the same, then the problem most likely lies in a weak signal in this area. In this case, you can make a compact antenna with your own hands.
How to make your own antenna for a modem
It is no secret that the main criterion for the effective operation of a modern 4G router, be it Beeline, Megafon, MTS, etc., is not the number of percentages, decibels and bars on the wi-fi scale shown by the control program, but the actual increase in speed. And the discrepancy between the speed parameters and the natural performance of the purchased modem is not yet a reason to refuse a particular Internet service provider. If there is a signal, then it is quite possible to amplify it, while increasing the speed and quality, using a home-made antenna.
Wire antenna
This is the simplest and most primitive option for do-it-yourself signal amplification. You need to take an ordinary copper wire and wrap one end of it 3-4 turns around the top of the 4G modem. Raise the other end up. This method will not strengthen the signal much, but can still make the connection more stable.
Can antenna
A very common idea that has been circulating among users of such routers for a long time and has enjoyed some success. But this method requires the ability to solder the parts yourself, otherwise you can damage the modem itself.
- First, you need to make a hole at the bottom of a tin can (can be a coffee can) for a tin bushing that will need to be soldered.
- Then, in the center between the bottom and the top, make a section that matches the dimensions of the 4G modem.
- Afterwards, insert the router itself into the hole made with the entrance facing outwards and point the amplifier towards the operator’s tower.
- Finally, connect the device to the computer using a USB cable of as short a length as possible.
IMPORTANT. It is better to install this design under the ceiling so that nothing interferes with signal reception.
This design is considered the most effective of all types of homemade devices and for this you need:
- Take a copper wire (3–4 mm) and bend it so that 2 identical rhombuses (with an angle of 120°) of small size (with a side of 53 mm) are formed.
- At the junction of the diamonds, solder a piece for fastening the high-frequency cable.
- To strengthen the antenna, you can attach a metal plate (reflector) to it.
- If the 4G modem does not have a connector for an external antenna, then you should wrap the central core of the cable around it with 3-4 turns.
IMPORTANT. There must be a distance of at least 3 cm between the antenna and the reflector.
If you have a satellite dish, you can make a wonderful amplifier with your own hands. To do this, you need to attach the modem to the focus of the already installed antenna, connect it to the PC using a USB cable and tune it to the desired station. But there is a nuance here: how to configure the antenna yourself. The plate should not be directed upward, like a television, but downward, periodically rotating it and using a special program to monitor changes in the Internet connection. After detecting the maximum value, the antenna must be fixed.
IMPORTANT. The Internet dish should not be connected to the television dish. And to protect the 4G modem from precipitation, you can use a bag or a plastic bottle, this will not affect the signal quality in any way.
To achieve the desired result, you may have to try different versions of homemade antennas. The main thing is that each of these methods really works and can really help, even in the most hopeless situation.
LTE is a new thing for the people, first we will evaluate logically what is implemented in the standard, then we will move on to reading the literature. The main difference between the technology is the increase in the speed of information transfer of the Internet connection. During test operation of LTE in Bishkek, the download speed was 20 Mbit/s. Because the limit is set so as not to overload the network. Surprise, in its original state (early 90s of the twentieth century), LTE was not considered digital. The protocol definitely contradicted the 3G specification, which cellular operators stubbornly refused to admit. A group of companies that had the honor of introducing LTE finalized the first option, then Yota began trying to cover Belarus first with the new standard, and when this did not work out, it covered the Russian Federation. Can an LTE antenna be made by hand? Of course yes!
LTE standard, LTE antennas
We avoid exploring the wilds of LTE. Let's mention simple facts: speed increases faster using information encoding methods and modulation methods. The polarization is almost certainly linear, vertical (typical of cellular communications). The frequencies adopted by LTE are not always respected in practice. The thesis concerns Russia. First of all, find out the wave (channel number) from your provider, then start constructing an LTE antenna. Today, every mobile operator broadcasts. In the Astrakhan region, LTE is distributed to two or three antennas. Everyone’s frequencies are different, the numbers change by region, and things are heading towards the fact that communications will become faster and cheaper.
We bring to the attention of newcomers: there is always a war for the frequencies of LTE operators, as well as television and radio companies. The range is not provided for free, the company is obliged to pay. The state benefits from the abundance of LTE operators - everyone waives the fee. It’s not new that large enterprises using walkie-talkies replenish the treasury with considerable sums. It’s difficult to say what LTE is paid for, but we believe it looks like this:
- Radio waves are harmful to humanity. Definitely a proven fact. They lower immunity, provoke poor health, and raise body temperature. The person feels completely sick and has been exposed to radio wave radiation.
- Therefore, the organization must take control so that citizens are not irradiated. Otherwise, the population will start to get sick, and nothing good will happen. The committee is GRKCH, if you are interested in more details, read the thematic reviews of the network for your health. The organization is engaged in frequency distribution.
We believe that the fees paid by LTE providers and other users of radio channels do not bring much profit (professionals will forgive the editors if we are mistaken). The money pays for the work of people who need to be paid salaries, sick leave, vacation pay... The state does not receive much profit from LTE. Don't be surprised if you can't catch operators with one LTE antenna. The range is considerable.
However, today we will show you how to make an LTE antenna that can catch everyone. Of course, you will have to sweat a little. We strongly recommend reading the literature, the book by Kharchenko K.P. 1969 release about VHF antennas. The title may be different, we believe that persistent readers will be able to download and read this work (pdf, djvu versions are posted).
Features of LTE antennas are limited by size. Suitable for GSM too. WiFi lies above. The LTE antenna picks up the upper television channels if you turn it so that the figure eight becomes upright (rotate 90 degrees).
How to make a good LTE antenna
A homemade LTE antenna can be an ordinary rod. We suggest doing something practical. You know, some people look down on biquadrat a little. Completely in vain. In the book, Kharchenko writes: with skillful design, the product is capable of receiving waves with a range overlap of 2 - 2.5 times. Let's now see what's happening with LTE in Russia. Many people broadcast... they take different frequencies, let's look at Wikipedia, so as not to conduct serious research, we will try to determine the parameters for creating a technical specification.
Each mobile operator does not seek to help competitors. LTE antenna KR – 14 – 2050 – JG, gain is 14 dB in the range 1900 – 2200 MHz. SWR does not rise above 2. So? Now take a look at Kharchenko’s work, compare the biquadrat with a store antenna. Still think that you don’t need to assemble anything with your own hands? There will be connection problems; the equipment does not have outputs for external antennas. We'll have to screw up the modems (a separate conversation) and find other methods for pairing the equipment. The good thing about the Kharchenko antenna is that matching is relatively simple. Let's start looking at the design.
For the tenth time, the VashTekhnik portal commemorates Kharchenko’s antennas with kind words. Let's try again…
Let's discuss the resulting product. The real Kharchenko antenna is formed by three circuits. Here is a drawing of the original 1969 edition; we hope the author will not mind this flagrant violation of copyright. As you can see, the dimensions are relative to the maximum wavelength (minimum frequency).
If you believe Kharchenko, the range overlap coefficient will be about 2 (up to 2.5). Nowhere in the SWR region will there be more than 2. Please note that the figure eight is vertical. The polarization will be horizontal. Kharchenko proposed to use the design when catching television broadcasts; the authors want to adapt the reception of communications. Place the biquadrat on its side.
It’s difficult to say how to connect the contours, the author hesitates to show... From the picture it follows: the largest upper square goes into the smallest lower one, and vice versa. The middle one closes on itself. At the contact pads, three circuits are assembled by a bus powered by a cable. It follows from the figure, there is zero explanation in the text. Having taken it as readers, we turn to the search engine, we don’t like unresolved questions... Here’s what we managed to find out.
Design issues for LTE antenna Kharchenko
According to the theory, which is not easy to find in a book, the diameter of the frame wire should be 0.016 - 0.02 of the maximum wavelength. For television frequencies from the times of the USSR it was:
- 1 – 5 (49 – 100 MHz) channels: 120 – 100 mm.
- 6 – 12 (174 – 230 MHz) channels: 34 – 27 mm.
It is difficult to find a wire of significant diameter; it was proposed to replace the round conductor with a flat one. The windage of the antenna has increased significantly, which cannot be called a positive factor, manufacturing has become more complicated, the weight has increased, and materials have become difficult to obtain. Three circuits are used. Good news: we will work with frequencies of 750 MHz and higher, everyone can get a wire with a diameter of 6 mm (stripe the PV). The second good news: we found a way to do the installation. The unknown author took the trouble to copy the drawings from the book and provided a description of the process on the website http://chegdomyn.narod.ru/meny/radio/ant-xarchenko.html. Free domain, so 99% of the information was obtained by a dedicated enthusiast.
The authors were too lazy to retake the drawings, let’s add a few words: two semicircular plates are placed on the sides of the circuit board, onto which the wire is soldered. At the corners (6 pieces in total) the frames are bridged with metal strips. They were right about the trajectories. Follow the picture, you can't go wrong. It is not customary to insulate the intersections of the wire; the antenna cord does not need this at all.
DIY antenna made for LTE. How to coordinate was written in a special review called DIY Kharchenko Antenna. Today, WiFi enthusiasts widely use the design. Sometimes they place the iron in a plastic case, finishing the seam with silicone sealant purchased at a plumbing store.
To access the Internet, I use a 4G (LTE) USB modem, although at the moment it works in 3G mode, because... The LTE (4G) network in my area has just begun to be launched and it is working in testing mode. I live in my own wooden house and before it was covered with metal siding, my modem had no problems with signal reception. But after covering the house with siding, problems began with the signal level in the house. The fact is that metal has a shielding effect, and the entire house is covered with metal, the roof is also metal. The screenshot clearly shows the low signal level; the reception speed was 1.5 – 2 Mbit/sec.
Signal level without antenna is minimal
In the summer, I solved the problem with signal reception by placing the modem out of the window onto the street; when it rained, the modem was removed into the house. But with the arrival of winter, it was necessary to look for another solution to the problem. That’s when I remembered about a small car antenna with a magnetic mount; this antenna had been lying around in my garage for about three years, because the car radio didn’t work well with it. the antenna was too small.
Third generation networks are most often deployed at a frequency of 2100 MHz. This is the accepted global 3G standard. Therefore, the receiving antenna should not be large. I did not go into abstruse calculations, but simply decided to test my car radio antenna in operation with a modem. To do this, I cut off the original plug from the radio antenna, because... Naturally, it did not fit the antenna connector of the modem; I stripped the central core and simply inserted it into the modem connector. To prevent the wire from falling out, I taped it to the modem with electrical tape. Then I put the antenna through the window onto the street (the window closes perfectly), secured it to the siding with a magnet and launched the modem program on the computer.
Car radio antenna with modem
The signal level became maximum, the speed of the modem in HSPA+ mode was 14 - 18 Mbit/sec when downloading from the network, and when uploading to the network the speed was approximately 6 Mbit/sec. I was happy as an elephant, now I’m waiting for the plug I ordered from Ali, then all I have to do is solder it to the antenna and be happy. By the way, a radio antenna of this type is much cheaper than a 3G antenna.
Simple antenna for 4G modem
The point of the video is not that the modem is hanging on a cord on the window, but that you can buy an antenna (the principle of operation of which is the same as described by me) for 1-3 thousand rubles. not worth it! And it’s easier to buy chocolate for your wife, mother, girlfriend, or yourself, finally, and do what’s in the video! Is it really so difficult to understand, before you write your exclamations about the fact that a simple lace will add something there, will you at least catch the meaning.
Necessary:
Cardboard. Aluminum foil, metallized textolite, etc. Scotch tape, electrical tape.
USB extension cable.
Your imagination and nothing more. This is the simplest method, which gave almost 10 megabits of Internet speed, there are others, but so far this one works with 1000% labor costs.
Discussion
- Yes, everything you say is correct. At my work, the modem also receives poorly, and the modem in an extension cord (3.5 meters) also does not receive much better. But instead of cardboard with foil (like yours), I used a Frisbee disk (plate) also with foil, and lo and behold, everything worked 5+. I cut off the outer edge of the disk and glued the food foil onto silicone. I placed the modem in the center and drilled a hole for the cable.
- What if it only catches on the roof of a private house? Cardboard too)? The cable will be long and the modem won’t even work through it. At one time I bought a directional antenna for 2k and did not regret it, I was the only one in the village who had 3G Internet). Now we have a clear 4G signal, civilization has come to us.
- Firstly, the modem is already hot, but here in the Sun and under the reflector... Secondly, this is called a reflector for an internal antenna, if there was an antenna, then the output would also be quite large. But antennas are not like that, they have a lot of benefits, not all have the main socket in the modem.
- Damn, I have a megaphone, I live in the suburbs of Yekaterinburg and 14 Mbit/s on 3g is not enough for me. The LTE signal is weak, the modem constantly drops to 3g. I wanted an antenna so that the modem could receive LTE stably. But I watched your video where you are happy about LTE at a speed of 6 Mbit/s and decided that I was greedy.
- I always doubted the effectiveness of this kind of handicraft. One fine day I was fed up with the low Internet speed and decided to scour YouTube in search of a solution to the problem. It just so happened that out of the mass of this kind of video, I included this one. Well, I think: whatever the hell, I’ll try it, the more it’s done quickly. I wrapped a thin flexible cutting board in baking foil and attached the modem to it on an extension cord (1.5 m) with two clothespins on the long side. And I rejoiced: the speed increased to 200 kbit/s. up to 7-10 Mbit/s. The signal increased from -69 RSSI to -55 RSSI. To improve reception, try vertical and horizontal orientation of the modem. I have a stable reception in horizontal.
- Conventional signal amplifiers like Connect 2.0 work like this, they have foil in parabolic plastic. I bought one myself because I was too lazy to bother with the foil on the roof, and it wasn’t expensive. If you point it at the tower, everything works great.
- The easiest way to strengthen (and better than any of the most expensive antennas) the 3G4G signal is to use a satellite dish. I used 0.9 meters Supral at the dacha. To protect the modem from external influences, I used a piece of pipe from the siphon + a rubber stopper from the drain + sealants and installed all this in place of the SAT converter in the antenna. The plate should be tilted STRONGLY downwards - not vertically, like everyone else’s on Tricolor or NTV+. Then I installed an electric distribution box next to the antenna and put the TP-Link TL-MR3020 there with the modem, connected it with a native USB cable, and from there I brought the twisted pair cable into the house, and then to the main ZyXEL Keenetic Lite router. Without a dish, reception was 3G with periodic interruptions and a peak speed of no more than 2 Mbps. With the antenna there was stable 4G reception (3 sticks out of 5, and in any weather the speed is about 15 Mbps, ping 35-45. The operator in this place has no 4G coverage at all on the map.
- A life hack about the fact that it is better not to buy a car with an engine, but simply lower the empty body down the hill. The principle of operation of the antenna is not just to catch a signal, but also to amplify it. And your effect can be achieved by bringing your laptop to the window. + If the USB cable is too long, the modem will periodically turn off due to lack of power. Therefore, if the signal is bad, make an antenna and connect it to the modem.
How to increase the speed of 4g LTE Iota? How to install a mimo antenna?
I bought an Iota modem, but there is no speed?
What to do if the Internet from Yota does not want to work?
How much do you have to pay for Yota, and how profitable is it?
If you have low speed 4g LTE from Yota in Tomsk, or in any other city, then you will need to boost the signal using a Mimo antenna.
The Mimo antenna actually increases the signal by 10-15 times, tested from our own experience.
Now the iota has begun to work more stable and better.
What you need to increase the signal:
1. MIMO antenna (Internet signal booster)
2. Coaxial cable
3. Pigtails
4. Any modem (Just not Iota)
Discussion
- Folks, if anyone wants to screw the Mimo antenna to the Iota modem, then there are MS 156 connectors, look for pigtails for it. Thanks to Denis Kulkov for the tip, and if anyone has a Huawei, the answer to the pigtails has already been given in the comments.
- For those who follow the example of the author, as M. Gorky wrote, “... so that it would not be excruciatingly painful for years spent aimlessly...” (in our case, money spent. So, 4G from Yota - remember these values: Yota works in the LTE band in two subbands: Band3 (1800) and Band7 (2600). In cities this is usually B7, in the suburbs B3. For B7, the carrier frequency is higher and the transmission speed is higher, for B3 everything is lower, but the range is better. Modems that you will buy for Yota you must support at least these two subbands in the LTE segment and support antennas made using MIMO technology (two connectors).The antennas you buy must support the frequency range 1700-2700 (well, at least 1800-2600) and be MIMO antennas . You can buy an antenna without a box and run cables from the antenna to the modem. In this option, there will be large losses on the cable and connectors, regardless of the quality of the cable. You can buy an antenna with a box and install the modem in this box, connecting the antenna to the modem with pigtails, and connecting the modem with a router and a USB cable - the losses will be minimal, but these modems are not designed to operate at subzero temperatures, so in winter there may be problems up to and including failure of the modem. In general, something like this, if on the fingers. Other operators use other subbands.
- from what you wrote, I took 1700-2700... but I took 3-4 g Internet from Iota, Megafon, Beeline or MTS for the Moscow region. I don’t know which provider you will use and at what frequency it operates in the region where you will install the antenna, so I cannot give you an accurate answer due to insufficient initial data in the question. What if you are “carried away” to some Skylink?
- Yota works on Lte via FDD in Band 3 (1800) and Band 7 (2600), everything else is superfluous. Now I’m writing from the dacha: ZyXEL 4g III, Huawei E3372, Agata 2×2 MIMO Box (1700-2700). Here, even any 3G is very difficult and only in some places, but I have 5Mbit/sec. easily.
- That's right, colleague! And to heat the modem in winter, you can use a simple 12-volt heater, there are plenty of them now.