Many summer residents have such a problem as high-quality reception of television programs in their country house. Spoiled by a good image on the screen in their city, when they go to the country (where the TV is probably not the latest model), they suffer from a sharp reduction in the number of TV channels received and from the quality of the image.
A radical solution to the problem, of course, can be considered the installation of a satellite dish. And the number of channels is about 200 (in a foreign language), and the quality is excellent. But satellite television still does not replace our regular channels, and we will consider a typical option - installing a mast for a television antenna. Typically, antenna masts are made from tall, slender ship's pine. Their height can reach 10-15 meters! At first, I also wanted to go the standard route - use pine. But after consulting with a neighbor who has just such a mast, he abandoned this idea. Firstly, you cannot install a serious “wave channel” antenna on such a mast. The “breaking” load on the mast increases sharply. Secondly, thin pine is very flexible. And in a strong wind, if it doesn’t break, it starts to sway quite violently. To prevent these vibrations from interfering with reception, you will have to install a broadly directional (and therefore ineffective) antenna. What were they fighting for? And thirdly, as the antenna engineers themselves recommend, the antenna mast should be metal and grounded. Otherwise, for its effective operation, it will be necessary to arrange artificial “earth”. And at the same time, the metal mast will serve as a lightning rod.
After weighing all the pros and cons, I decided to make a metal mast. The design, of course, was not discussed - of course, on the telescopic principle. There are two types of material to choose from. Pipe or rectangular profile. The mast from the profile was removed because the profile, being long, is weak in torsion. In addition, it is more expensive and heavier.
5 pipes were purchased, each about 3-4 meters long, and those whose internal diameter coincided with the external diameter of the thinner pipe. So that they can be inserted one into the other. A “wave channel” television antenna with an amplifier in the antenna itself was also purchased. (By the way, wave channel antennas are among the most effective). An amplifier is necessary to compensate for signal attenuation in the coaxial cable and, in general, to amplify the signal. After all, the descent was supposed to be quite long, about 20 m. And to the television center it was generally about 100 km.
The thickest pipe (mine is 55 mm in diameter) was purchased with a “tail” of 1.5 meters. A piece about 2 meters long was cut off from it (another 2.5 m was left for the mast itself). A hole is dug at the antenna installation site, as narrow and deep as possible. A piece of pipe is lowered into the pit and driven as deep into the ground as possible using a sledgehammer. In this case, approximately 50 centimeters of protruding pipe should remain above the ground. The pit is filled with concrete, which is allowed to set for several days.
A piece about 60-70 long is cut from a pipe with a smaller diameter and welded into the protruding pipe so that a piece of pipe about 30-40 centimeters sticks out of it. Why is this necessary? The fact is that effective television antennas have a very narrow radiation pattern - literally a few degrees. Therefore, initially it is simply impossible to orient them strictly towards the transmitting TV tower. And it is necessary to be able to rotate the television mast in a horizontal plane in order to direct the antenna strictly at the television tower or repeater. In addition, if there are several television centers, this makes it possible to rotate the antenna in one direction or another.
There are two ways to assemble the antenna itself. First, the antenna is welded in a horizontal position. In this case, a thinner pipe is inserted 30 centimeters inside a thicker one and welded around the perimeter of the end of the thicker pipe. When the antenna mast is ready, the television antenna itself is securely installed on its top with a connected cable of the required length. The cable is loosely attached to the mast using clamps. The cable must not be strained. It is necessary to leave a little slack - thermal compensation for the winter period. Otherwise in winter it may burst. The mast is high and it is not recommended to run the cable inside the pipe. You are unlikely to be able to secure it inside the pipe (unless you pair it with a cable in advance). The cable is quite heavy and if you hang it out, sooner or later it will break under its own weight. In addition, the exhaust hole is an extra voltage riser. If the pipe ever breaks, then rest assured it will be in this place. Therefore, I recommend not to take risks, but to run the cable along the outside, securing it securely with special plastic clamps every 50 cm. They cost pennies, do not break, do not crack and last forever.
At the required height, a thin metal cable is attached to the mast. And the antenna release (feeder) is attached to this cable. So that the cable does not experience breaking stress from its own weight.
The hardest part is lifting and installing the mast. Actually, she herself is not heavy, about 60 kilograms (I lifted her freely). But due to the fact that it is very long and the center of gravity is located at approximately 4 meters in height, it is not possible to lift it alone. The mast was raised as follows. A long rope was tied at a place 2 meters above the center of gravity. The rope was thrown over the ridge of the house, which acted as a block. After which the antenna was quickly brought into a vertical position and placed on the rotating device.
The second method of assembling the mast eliminates the procedure of raising the antenna itself, but involves its assembly on site. But for this you need to be able to work at a height of 3-4 m. And carry out welding work there. With this method, all pipes are first cut to size and then inserted one into another, forming a kind of telescopic antenna. Then, having attached the antenna to the very top of the mast, they pull out the thinnest link and weld it to the second. As it extends, the cable is attached to the mast. And so on until the mast is completely assembled.
After connecting the antenna and setting it up (orientation), I was pleasantly surprised by the results of the work. In the Pokrov area (Vladimir region, ~ 100 km from the Ostankino TV tower), all 15 broadcast channels are perfectly received. The height from ground level turned out to be just over 13 m. In addition, I attached a 2-meter “pin” for the CB radio station (civil band 28 MHz) to the mast. The mast with the antenna showed excellent aerodynamics. The day after installation there was a strong wind, approx. 15 m/sec. The mast hardly swayed.
Yes, the mast itself cost less than 1000 rubles. Moreover, all pipes (except the thickest) are galvanized.
A low-quality television or Internet signal is a fairly common problem for country houses. To solve this, you need to mount a high mast to install the antenna.
Why do you have to make antenna masts yourself?
There are a number of ready-made models available on our market. However, these masts are not cheap. And the choice among them is limited. They mainly produce either low-height brackets for installing a satellite dish on a facade or roof, or high triangular masts, more suitable for industrial use. But many owners of country houses need a higher mast to accommodate an antenna designed for an over-the-air television signal. Also, on such a support you can place two or three “plates” at the same time (for example, one for a television signal, the second for the Internet). In addition, the mast is often used to install a Wi-Fi receiver or an external antenna that improves the reception of a 3G signal (mobile Internet).
Therefore, you should make the mast yourself or order its production from a company engaged in the production of metal products (be it stairs, window bars, fences, etc.) There are several methods for manufacturing, assembling and installing pipes. The methods described below are not the only possible ones. The main thing is to understand that simply walling up a piece of durable pipe in the ground or securing it to the facade of a building is not enough. To build a good mast, you need to assemble it correctly and complete all stages of work in the right sequence. After all, it is better to plan well and take into account all the little details in advance than to redo or re-build the structure in the future.
Material selection
For stable operation of the equipment, it is necessary to secure it in a high-quality manner. But if terrestrial television allows a certain range of antenna movement, then millimeter tuning accuracy is important for a satellite dish or Wi-Fi receiver. Therefore, the support must be made of strong and durable material. At the same time, it must allow for ease of assembly and disassembly of structures.
Metal pipes fully meet the requirements listed above. They are convenient to use due to their good torsional rigidity, even with long product lengths (although a high mast still needs to be reinforced with guy wires). But the corners for making elongated sections of the mast are not suitable, since the situation with the latter characteristic is worse for them. In this case, the weight of the corners with equal geometric parameters will be greater than that of the pipes. And the price is higher. It is better to make short supporting elements from the corners, in particular brackets for fastening to the facade of the building.
The metal used to make pipes can be different. Perfect fit steel pipes with a wall thickness of 3-4 mm. Second option - aluminum. The strength of a mast made from it will be lower (but quite sufficient), but the weight will be noticeably less (which is useful from the point of view of ease of assembly and installation). The same can be said about duralumin (duralumin) pipes, which are made from aluminum alloyed with manganese, copper and magnesium. In all cases, additional protection of pipes from corrosion is required. To do this, their surface is polished and covered with a layer of paint or enamel. But wood, plastic and fiberglass are tempting things, but not suitable. Masts made of such materials will weigh little, but cost a lot. And resistance under the influence of mechanical and wind loads raises questions.
Geometric parameters
You should calculate in advance what mast height is required. The required amount of material depends on this. Of course, the higher the mast, the better the signal reception. But a reasonable approach is important here. If the house is located in an area with difficult terrain, and the local relay station is at a distance of more than 15 km, it is worth raising the antenna to a height of 10-12 m. In other cases, it will be enough to maintain a level of 5-10 m. Install a mast for home use with a length of 15-20 m is pointless. The gain in signal quality will be minimal, and the problems with installation and consolidation will be much greater.
To begin with, a small introductory note, as a kind of summary of the work done. So, it’s worth starting to implement such a project if you have an extra 50 thousand in your pocket, a great desire to have high-quality radio communications, mainly when working in walkthroughs, You are not afraid of the sidelong glances of people around you or you’ve been used to them for a long time (hee hee), and you have a lot of enthusiasm that has nowhere to go.
If you weren’t scared and read up to this point, then most likely you can handle such a project. When I started this epic, and it lasted about 3 months, I had no idea about the operation of such antennas, nor about the principles of installing antenna mast structures. However, patience, work, the experience of senior comrades and the poke method sometimes produce remarkable results.
Antenna
The design of such an antenna was found in a single source, on the manufacturer’s website in the states http://macoantennas.net/, except for the mention of similar designs in RuNet, alas, there are no materials on such antennas. Maybe I didn't search well. By the way, on the manufacturer’s website in the instructions section you can find drawings with all dimensions, however, only in feet and inches (America’s), but for an enthusiast this is not a hindrance.
Before building any antenna, it needs to be modeled in order to have an idea of what to expect from it in the future. For calculations of any types of antennas, I recommend using the MMANA-Gal program. The program is somewhat inconvenient to learn and use, but the output gives an excellent result, which, if repeated in real life, will be very close to the theory. I will not describe the technology of working with the program; Comrade I. Goncharenko has already done this in his book “Computer Modeling of Antennas”; I will only tell you about the finished results.
In general, creating an antenna is a creative process. You can’t rely on one structure and only work on it. There are a lot of other interesting options that can be obtained by changing the design and changing the sizes of certain elements, which, however, does not negate the principles of operation of the antennas.
In order not to describe my throwing in detail, I will only say that for one reason or another which I will write about in the course of the story, I came to the 2-element design of the hybrid of Yaga and Kvadrat (at the suggestion of Anton - 165 from Alma-Ata).
Calculations.
The antenna consists of a vibrator in the form of a dipole with gamma matching and a reflector in the form of a square of wire of a certain diameter at a certain distance from the vibrator. In the original design there are 2 vibrators, for quickly switching vertical and horizontal polarizations. Power comes through two cables. The vibrators are arranged crosswise and do not influence each other, and the reflector is a common one. In the modeler the whole thing looks like this. The length of the vibrators is approximately 5 meters (actually adjustable on site), the distance between the reflector and the vibrators is approximately 1.4 meters. The reflector perimeter is 11.8 meters. The perimeter of the reflector is a very important value; the behavior of the antenna, suppression of the back lobe and forward gain depend on it.
Radiation patterns and SWR for vertical polarizations
Radiation patterns and SWR for horizontal polarizations
The best amplifier is an antenna. As can be seen from the calculations, in both vertical and horizontal polarization the antenna gain is approximately 11idB, which in practice is equivalent to an increase in transmitter power by approximately 12 times. We conclude that the antenna is worth repeating.
Great, we’ve decided on the dimensions and dimensions, now we need to think about the design. Based on the fact that most radio amateurs do not have access to a fleet of processing machines, the antenna design was developed based on the realities of the materials market and the capabilities of the average radio amateur. Looking ahead, I will say that with similar materials, which are quite easy to get nowadays, anyone can replicate such an antenna and any other such as Yagi or Kvadrat!
Based on the dimensions, aluminum pipes were purchased from the OBI store.
Aluminum tubes. Antenna base.
Diameter (mm), wall thickness (mm), length (m), quantity (pcs).
40х1х2 – 2 (antenna boom)
25x1x2 – 5 (the base of the vibrators and the reflector crosspiece, if you can find 22-23mm, it’s better to take them)
20х1х2 – 4 (vibrator elements)
18x1x1 – 8 (vibrator elements)
Gamma matching.
12x1x1 - 1
8x1x0.5 - 2
There are also 12x1x2 pipes in the photo, they are not relevant...
In the list, the number of pipes is taken with a reserve, since at first it was planned to make a three-element antenna, so the excess can be thrown away, sold, made another antenna and sold. Essentially, there is enough material for two 2-element antennas or one large 4 or 3-element antenna.
Next, prepare the pipes as follows. Pipes with a diameter of 20mm, we cut them in half and get pieces of 1 meter each. For 20mm pipes, on one side we make a cut from the end along the diameter to a depth of about 4 cm, 3mm wide, and at the end of the cut we drill a hole right through. It is done with a regular hacksaw for metal with 4 cuts plus one drilling. I did it without drilling, but now I understand that it would be very useful. Next, we insert the 18 mm pipe inside the 20 mm pipe and fix it with a car worm clamp. You need to insert it to a depth of at least 15cm. The main task is to make sure that one pipe inside the other does not rotate or dangle. It is important not to overtighten or break the clamp. It should look something like this.
As a result, we should have 4 assembled elements for a 2-element antenna and 8 for a three-element antenna (I am writing about 3 elements based on the amount of material above).
We do the same with 25 (22-23) mm pipes, only we make cuts at both ends and also drill right through. These will be the bases of the vibrators into which the elements made earlier will be inserted. Next, we assemble the vibrator. We insert the elements at both ends and secure them with a wide power clamp. Since I have base pipes with a diameter of 25 mm, I couldn’t even clamp them with a power clamp; I had to make liners from construction steel punched tape 1 mm thick.
Next, we proceed to the production of gamma matching.
It consists of 2 tubes with diameters of 12mm and 8mm inserted into one another. The length of a 12mm tube is approximately 30cm, an 8mm tube is 50cm. The 8mm tube is equipped with an insulator made of silicone hose. Thus we obtain a trombone-type variable capacitance. One end of a 12mm tube is heated using gas or some other method and flattened. A hole with a diameter of 4 mm is drilled in the resulting plane. This will be the part attached to the central core of the feeder.
Next, mounting plates of a suitable size with suitable holes are purchased at a building materials store, bent in an L shape, and gamma matching elements are attached to them. The feeder connector is mounted on the mounting plate and an “O” type crimp terminal is soldered to the center conductor. A 12mm tube, which we previously flattened and drilled, is screwed to this terminal. The connection must be made with the Grover washer, so that nothing gets loose from shaking and vibration. To attach the “gamma” to the vibrator, you can use plumbing clamps designed for fixing pipes on walls and ceilings, removing the rubber seal from them. It should look something like what is shown in the photographs.
The attachment points for the vibrator, reflector and crosspiece of the square spacers will be attached to the boom as follows. For this we use a mounting plate measuring 185x40x2, a step-ladder clamp from the Oka muffler (41.5mm), and pipe clamps 21-25mm for fastening heating pipes, they already have a welded nut and an insulating rubber band. We assemble it like this (in the photographs the plates are without drilling for the clamp). Drill 2 holes for the clamp.
Next, we proceed to the manufacture of the reflector and its fastening. Chinese fiberglass fishing rods 4 meters long, which are sold in fishing stores for 300 rubles apiece, are perfect for the reflector crosspiece. I took Clasix Pro 300 fishing rods. We buy 4 fishing rods and remove the top, thinnest, knee. To do this, unscrew the plug at the bottom of the rod, bite off the top ring and shake out the thinnest leg. The rest will be useful to us. The lower part of the fishing rod, where there is a plug that prevents the fishing rod from falling apart, is cut off with a Dremel. It’s better not to cut with a hacksaw, as there is a chance of splitting the fiberglass and you can throw away the fishing rod and go to the store for a new one. We wrap the sawn end with good electrical tape so that the cut does not start to split.
Next, we cut a 25mm pipe 2 meters long in half, and get 2 meter pieces. Using electrical tape, we adjust the size of the fishing rod to the inner diameter of the pipe and insert the fishing rods into the pipe from both ends. They can be fixed inside with glue or heat shrink. I chose to use electrical tape and heat shrink the top. Despite the somewhat artisanal design, it is very reliable and will not fall apart. In addition, there will be almost no load on it.
So, after carrying out all the operations, we have an almost ready-made kit for assembling a 2x - 3x - 4x element antenna, and the configuration can be very diverse. This set of elements allows you to assemble antennas, Yagi and Q-Yagi, 2,3,4 elements.
Another important detail is the boom holder and attachment to the mast or turntable. I won’t describe it in detail, everything is clear from the photographs.
Everything is ready to assemble the desired antenna and experiment. Perhaps some improvements can be made to the entire structure or to its individual components, which are not obvious to me, but will be useful in order to increase the efficiency or reliability of the structure. Antenna construction is a creative process.
The construction of antenna mast devices is an important and responsible matter. Safety issues must come first. It is necessary to think through the entire sequence of actions when preparing the structure, its placement on the intended territory, as well as the materials from which it will be made. Elements should not interfere with the owner and neighbors (if any), especially when the structure is erected on a summer cottage or in other dense buildings. Careful planning of the location on the ground, methods of lifting and ease of installation, the shortest distances for laying power cables, installation of a winch and other little things must be taken into account at the design stage; eliminating or altering is always more difficult than building anew. Take your time, nothing should overshadow the result of your work, because you will get a real thrill from the first connection made on a new structure.
ANTENNA SELECTION
So, the task: minimum space, ease of maintenance, low windage, ability to rotate. The most painful thing is to decide on a specific type and type of antenna. Efficient antennas with high efficiency and a narrow radiation pattern, primarily multi-element and full-size. I have experience using antennas from overseas, other than the beauty of the execution, I can’t say anything positive, I just wasted my money!!! I immediately brushed aside such garbage and settled on QUAD or YAGI for frequencies from 40 m and above, GP for 80 m and 160 m. Today, on the market for high-quality antennas, I would single out two of our manufacturers: R-Quad and ANTennae Depot. The rest did not attract me either in terms of quality, service, delivery, price... and many other small factors that spoil the face of the manufacturer. I really wanted to have an RQ-54 (57), but the dimensions of this antenna and its weight do not allow assembly (in my case) in a limited space, besides, to install the RQ-54 (57) you need a durable UNZHA type mast and a powerful rotating device type P-10 or similar. Therefore, I decided to choose an easier option for myself: YAGI and GP. Although squares have a higher gain, they are still inferior in size in terms of construction, maintenance and prevention during operation. I chose fairly high-quality antennas from ANTennae Depot, such as: the first - AD-347, tri-band (20m-15m-10m); the second is N3L, for one range (40m). I will arrange them in two tiers on one stand, which in turn will be rotated using a Yaesu G2800DXA rotary device. For low ranges - Vertical MBV-21.
MAST
I’ve decided on the antennas, naturally I’ll install the vertical separately, for the rest I need a mast. Since all the good masts produced are not cheap, I decided not to buy them and decided to make them myself. Consumables will require two water pipes (wall = 3.5 mm) of standard length and a diameter of 76 mm (or 89 mm) - this will be the main mast. One pipe 4.5 m long with a diameter of 60 mm (a rotating stand for mounting antennas), a corner 25x25 mm (for making a rotation unit) and a steel rod (for steps). Also rigging: cable for three tiers of guy wires, nut insulators for breaking guy wires, cable clamps, turnbuckles, screw carabiners and thimbles. We'll talk about guy wires later, but now let's start making the mast. The mast is made up of two pipes (the height of the mast is a little more than 20 m, and the antenna is 23-24 m); to connect the pipes, you need to make an insert of a smaller diameter and about 1 m long (50 cm in each section for vertical stability). The insert should fit tightly inside the main pipe, then it needs to be secured on one side (I scalded it). On the other side I will fix it after inserting the upper part of the mast. 
To install the mast (lift), you need a base (anchor platform) and a hinge unit. I made it like this: I prepared a hole in the ground with a drill, about two meters deep and 25 cm in diameter, inserted and concreted a pipe with a diameter slightly larger than that of the mast. In our latitudes, the depth of soil freezing is approximately 1.3-1.5 m, so that the foundation does not play (does not rise in winter and does not fall in summer), it is necessary to install foundation structures below the frost layer. On top I made the same hinge for lifting the mast from channels of different widths (see photo). The next step was to bend the rod under the steps and weld them to the mast at the distance of the lifting step, I did it after 40 cm, and also welded the brackets for the guy wires.
Now the time has come to manufacture the rotating unit (mast head). The design of the rotary unit is made of 25 mm steel angle and consists of 2 halves. The height of the unit is about 3.4 m. A support bearing is attached to the upper part. In the middle there is a steel half-plate 10 mm thick, at the bottom in the center of it, a bushing for attachment to the mast is welded, and a G2800DXA gearbox is bolted on top. The design is compact, the width of the sides is about 20 cm, the gearbox does not pass between the corners (I deliberately made the unit narrow so as not to float, and from an aesthetic point of view it looks decent, again eliminating excess weight), so the design is detachable. A bushing with a through hole for fastening to the mast with an M12 bolt is also welded to the plate at the bottom of the unit. The knot is assembled immediately before lifting.
To assemble the halves of the assembly, overhead parts are used, to the lower section, on the outside, fastening corners (length 45-50 cm) are welded in an overlapping manner, to the upper section I fasten them with M8 bolts, 2 pieces per corner, and place them mutually perpendicular (see below, in the photo I marked the holes with red arrows, welding with blue arrows). So the load-bearing vertical parts of the corners rest on the lower ones “at the end” and are bolted to the sides.
Having prepared the main elements, when assembled, I begin to make tacks using welding. Why? I explain: in this position, the flanges, plates, angles and other elements of the assembly will be coaxial, I am sure that the plane will not move, the required angles will be maintained as necessary for the rigidity and proper functioning of the rotating device. About 100 kg will hang on it, when turning the antenna it is very important that the axes of the gearbox and support bearing coincide, otherwise your gearbox will be destroyed during the first test.
When all the tacks are made, I scald the structure, having previously removed the gearbox and support bearing with the stand pipe. Upon completion, I put it back together and check the rotation of the rack by hand and using the gearbox. If the assembly structure does not deform during rotation, you can congratulate yourself. If not, you need to find the cause and eliminate it. I forgot to say, on the flange where the support bearing is attached, I provided holes for attaching the upper tier of guy wires, and even lower, 50 cm, I welded brackets for attaching guy wires, I don’t know yet, perhaps placing the guy wires too close to the antenna will interfere, in this case I can lower them lower. The unit is ready, you can paint all the elements and assemble the mast.
MAST GUYS
Preparing stretch marks is a painstaking task, as it turned out in practice, it takes a lot of time and maximum patience. Since the main incentive is to build for myself, I overcome this stage with enthusiasm. I’ve never been involved in cable tying, I’ve only seen it from the outside and from stories. I looked on the Internet, it’s somehow stingy, there is rope tying on the sites of yachtsmen, and the owners of sites for extreme sports and motorists. I didn’t waste time on the World Wide Web; I couldn’t find a rigging reference book; I acted on my intuition. I have repeatedly seen finished products, especially good ones from aviators and warriors. The main thing when tying cables is the maximum coefficient of friction between the strands of the cable. An exceptional option is to braid each strand towards the other, and also using the intersecting method. I refused it, it was too labor-intensive, I chose a medium degree of complexity, strong and reliable, it does not take much time to prepare. I’ll tell you about it a little later, but first I’ll check it myself. I made a sling - there were two loops at the ends of the cable, and I installed two clamps on the braided ends. Let's see what happened...
Tests on a tensile testing machine showed that the choice of knitting method was correct; now I do it myself with 100% confidence and recommend this method to others. The sling made of cable withstood a load of 1.5 tons and broke with a force of 1.6 tons. The loops and presses remained unharmed, moreover, the cable in the loops did not even stretch! Thanks to friend and chief tester Alexander Zaitsev!
Now, in order. For guy wires, I chose a galvanized cable with a diameter of 6 mm. Walnut porcelain insulators IAO-2 with holes, although the cable fits tightly into these holes, in my opinion, they are more practical than IAO-3, the latter are much larger and almost five times heavier, they hang on this cable like watermelons on a thread. The electrical parameters of both types are approximately the same; they have no effect on stretch marks, and even if they do, it is absolutely unnoticeable in practice.
The breakdown of guy wires should begin by determining the length of the breakdown pieces. The shorter the length, the better, but with short ones there is more fuss. Long sections will affect the antenna's performance. Theoretically, it is necessary to choose a section length such that it does not resonate either at the fundamental radiation frequency or at harmonics, so that it does not absorb the active component of the antenna radiation. Since the guy wires also represent an inductive-capacitive load, close proximity to the antenna shifts the antenna resonance down the range . Try to reduce the influence of these factors as much as possible.
There is an endless debate among radio amateurs about whether to break tripwires or not. For example, A. Dubinin (RZ3GE) A. Kalashnikov (RW3AMC) V. Silyaev in satya “The influence of mast braces on the performance of antennas” It is believed that the degree of influence on the antenna's radiation pattern is so small that it is possible to do without setting up the guy wires. Hundreds of antennas across the country, including those of military personnel, have been operating for many years. From a physics course, any schoolchild knows that the landscape, nearby houses and trees, power lines, and even more so guy wires located in close proximity to the antenna affect the characteristics of the antenna; it would be naive to ignore this fact. Personally, I have had practical experience that disproves the article's assertion. I used 2el-QUAD-40 m with wired guy ropes, after breaking up the upper tier, the performance improved slightly thanks to my colleagues who suggested it. About 25% of correspondents, when conducting QSOs (repeated ones), rated the signal strength a point higher. Sometimes, to conduct a DX QSO, the very little thing that we argue about is not enough! The choice is yours!
I chose a cable cutting length of 1.7 m, taking into account the fact that part of the cable will be used for bending and knitting loops. I do the cutting using a cutting wheel and a wonderful tool, popularly called a “grinder”. This particular method is good because the end of the cable turns out smooth, undeformed (as if cut off with a chisel or cleaver), and when braided it lies flat.
Let's start making sections of guy lines, knitting loops (a loop is called a fire). First, we unravel the cable into strands; if your cable consists of an odd number of strands, try to break it in half with an advantage of one strand. The length of the unbraided part is 25-30 cm. We thread the first half of the cable into the hole in the insulator and secure the end in the third hand - a yew. We insert the second half of the cable from the opposite side of the insulator, as a result, the ends of the cable are directed towards each other. Please note that when unbraiding the cable, the strands are formed in such a way that they are in a group spaced from the axis of the cable. Try not to destroy this formatted state, because when weaving, the opposite half of the cable occupies exactly this place, and the woven part becomes even (see photo). I cut the rope that runs inside the cable at the point where it unravels. Of course, it would be nice to leave it and braid it into a loop, but for me it constantly crawled out of the cable, the loop turned out like a shaggy hedgehog. That's why I cut it off.
Once you have wrapped the groups of strands around each other in a loop, and have reached the point of unbraiding, it is time to think about how to braid the ends into the main cable. What is there to think about, it’s simple! We take a screwdriver, insert it inside the loop, then rotate it along the turns of the cable plexus, while holding the remaining strands from the loop. With this installation, the ends fall into the crevice under the screwdriver and lie neatly between adjacent strands of the cable. After you have gone through the turns of the cable, the final part is to keep the ends from unraveling; they can be secured with rope, thin steel or copper wire, whichever is more convenient for you.
I didn’t fix it with anything, I held it with my fingers in a glove (and without it), fortunately the cable is soft, it didn’t hit my fingers when pulling out the screwdriver. First of all, I fix this part with a press, then I move to the next place, install the press near the loop and control(!) - in the middle. Please note that after installing the first clamp, you need to wrinkle the cable (bend it in different directions) so that the strands fall into place, the same must be done when installing other clamps, only in this case there will be high-quality crimping and fixation. When installing the presses, I used a yew, the main thing is not to pinch the cable, the strands should not be deformed.
A few words about clamps. First: my cable has a diameter of 6 mm, the diameter of the braided part increases, so buy crimpers for crimping a cable with a larger diameter. I used presses under an 8 mm cable, everything worked out well.
Second: there are many types of presses on the market, I recommend these (see photo on the right), the clamping part of the press should be rounded, on the flat part the cable strands spread out to the sides, the quality is slightly worse. There are figure-eight presses, they say that if the cable is laid correctly, they also hold well, I personally have doubts, and with my braiding technology it’s difficult to use them.
The choice has been made, I continue to methodically repeat all the steps for each section, thereby increasing the length of each stretch. When the length of the assembled sections reaches the required length, I attach the ends of the guy wires to supports (for me these are trees) at a height of 1.5-2 meters, then I pull them out using a weight, hang about 100-150 kg in the middle and let them hang for an hour. two. Pre-stretching is needed to ensure that the thread length of the turnbuckles is sufficient for tension when installing the mast. One more thing, I don’t do the breakdown of the guy lines completely, the top tier is about 20 m, the middle one is 15 m, and the bottom one is 10/12 m. The guy line diagram is shown below, I think everything is clear in the picture.
The final part is installing thimbles (a bracket inside the loop to protect the cable from abrasion). The thimbles in stores sell different wall thicknesses, choose thicker ones, they will last longer. You also need to pay attention to the shape of the thimbles. To ensure that the thimble “sits” tightly in the loop, select a configuration that is as close as possible to the shape of the loop, then it will not dangle in the loop and will not fall out when installing guys on the mast. The photo shows different types of thimbles as an example. The first one on the left is too round and short. In the middle - made of thin steel. I chose the last one (far right), it just satisfies my conditions described above (the wall is thick and the shape is just right!).
I install thimbles at both ends of the guy lines, since they will be attached to the mast using screw carabiners, and to the anchors using screw carabiners and lanyards. This makes it more convenient to install or remove guy wires for repairs, replacements and other maintenance.
When making guy ropes, there were some blunders! The clamps that I took, some turned out to be defective (shells on the clamping part), when tensioned they naturally split, and on the studs I went too far - I tore off the threads and accidentally split the insulator... So I advise you to take materials with a small reserve in order to counteract small ones force majeure moments.
Anchors for guy wires
Guy anchors can be made in several ways, the main thing is that the anchor exceeds the design load. I won’t describe these methods, I’ll tell you about mine. At first the idea was to install reinforcement (steel rod), the upper end was a bent (or welded) loop, the lower end was fixed with a plate or pieces of other reinforcement by transverse welding and filled with concrete.
I settled on a simple and accessible option for me. I use pieces of pipes as anchors. Using a drill, I prepare a hole for the future anchor, and drill it at an angle so that the axis of the anchor is perpendicular (or close to a right angle, if possible) to the tension axis. I install the pipe and fill it with concrete. At the end of the pipe there are welded brackets for attaching guy wires.
A few words about the tool with which I dig holes. I didn’t find a suitable tool in stores, although there was one copy, with a diameter of 100 mm, but it cost as much as an airplane. Since I have skills in everything, I made two drills myself, one for preparing holes (holes in the ground) for anchors of heavy structures such as masts. The other is for lightweight anchors, such as vertical stays. The large drill is made of an inch pipe, the handle is made of a half-inch pipe, the bucket is made of a pipe with a diameter of about 20 cm. I welded the lower part (see photo) in sectors of 2 mm sheet iron, bent a cone, and welded more strong material, sharpens the cutting edge accordingly. I would like to draw your attention to the fact that the cutting part should protrude from the side of the bucket by 1-1.5 cm, so that the bucket does not get stuck in the hole, especially if the soil is wet, it will be difficult to remove the soil. The bucket is needed to lift the earth out of the hole. If you leave only the cutting part, the earth simply falls off the wings, and the side walls of the bucket hold it, digging and drilling is a pleasure, it turns out very quickly, compactly and neatly! Here's what happened:
The second is a small drill, made from a half-inch (20 mm) pipe 1.3 m long. At one end I attached a flange with a diameter slightly larger than the diameter of the pipe (mine is 90 mm) made of sheet iron, 3 mm thick. I sawed it down to the middle with a grinder and bent it like an auger. The distance between the cutting and ejecting edges is about 4-5 cm. This opening is needed so that small stones, roots and other components in the ground pass along with the soil to remove them from the hole. I welded a piece of a regular drill into the center of the axle (see photo). A piece of three-quarter (25 mm) pipe was placed on the upper part; it is needed in case of extending the drill handle and is fixed with a bolt and nut. You can use a regular ice drill (ask the fishermen), but after minor modifications to the cutting part, the soil is still not ice!
MAST LIFT
All preparations are completed, it is time to raise the mast. I divided this stage into several parts, namely:
1. Lifting the lower section, final adjustment of the guy wires to length, their fastening, marking the first tier.
2. Lowering the lower section, extending the mast.
3. Raising the mast, final adjustment of the guy wires along the length, fastening, marking of the middle tiers.
4. Lifting and securing the boom.
5. Raising the headband (swivel unit), final adjustment of the guy wires to length, fastening, marking the top tier of guy wires.
I'm waiting for a fine, windless day, and I'm starting to prepare for the climb. I install the mast section on the swivel assembly and supports (wooden beams to support the pipe), taking into account the direction of lifting. Next, it is necessary to secure the “falling boom” - it is through it that the tension force of the winch cable is transmitted, which greatly facilitates the lifting of the mast. The length of the boom is about 4.5 m. A small nuance: the boom must also be secured with guy wires in a vertical position, this is necessary so that when the cable is pulled, the mast does not move to the side. The boom stays are installed at right angles to the direction in which the mast is raised. Make sure that the torso force is directed exclusively vertically, otherwise you can “tilt” the mast on its side and, as a result, bend it. For the same purposes, halyards (nylon cable, mine with a diameter of 8 mm) are tied at the upper end of the mast; if necessary (during lifting), assistants adjust the vertical by tensioning them. These halyards will later be used as temporary guy ropes. In the picture I showed the general lifting scheme, nothing new, a classic option that is used by thousands of people when lifting various structures.
One more detail: I made the cable from the winch to the “falling boom” and the cable from the “falling boom” to the mast with separate slings. This is necessary so that during the lifting the cable does not roll on the end of the falling arrow, much less break. If the design is one-piece, then it is necessary to provide additional fixation at the end of the “falling arrow”. I’m starting to climb, the section is easy (about 60-70 kg in total), so I do without assistants, I do all the work alone. To prevent the mast from falling toward the winch, I fixed the halyard to an anchor on the opposite side of the mast before lifting.
After reaching an angle of approximately 80 degrees, I stop the lift and attach halyards (temporary braces) to the anchors. Then I continue lifting, the entire mast is in a vertical position, and proceed to adjustment. Using the tension of the halyards, I adjust the plumb vertical of the mast (the first section for now). Next, I secure the first tier guy wires to the top using carabiners. I check the length, braid the ends, install turnbuckles. I attach chains to the anchors to which the lanyard will be attached. The chain is needed in order to be able to adjust the length of the fixed braces, and also, when weakening, to eliminate sagging. After all, the cable is new, but the places where the insulators are braided have not yet been stretched, there are few threads in the lanyard, so you have to lengthen or shorten the stretch link by chain link. After adjusting the mast, I mark with paint the chain link to which the lanyard is attached. This will be useful during subsequent operations in order to know at what length to fix the stretch. Note: In the left photo, on the left side of the mast base, a “falling arrow” is attached to the gusset. This is an ordinary pipe, grooves are made at the ends for attaching the cable to the mast, cut lengthwise using a cutting wheel and holes are drilled for an M12 bolt.
I’m done with the first tier, I’m moving on to the next stage: descent - all actions in reverse order. I build up the mast, fasten it at the junction, prepare the halyards, and naturally invite friends (4 people, three on guy ropes, one as a helper). Since the mast is quite long, and the pipes are relatively thin in diameter, there is no way without help!!! I attach a lifting sling at a distance of a little more than two-thirds of the length of the mast (see diagram above) and begin the climb. The operations are familiar, they are repeated, I perform everything according to the proven scheme. When lifting, the mast begins to sway, so you need to hold the top of your head well, and the guys cope with this successfully. Next, we attach the first tier of guys to the marked places, stretch the halyards and attach them to the anchors. The assistants can be released, painstaking work begins with the guy wires of the second tier, I hang them, measure them, braid them, fasten them, and mark them.
Now comes the turn of installing the “headrest” (rotating device for antennas). To install it, you need one person at the bottom who will carry out lowering and lifting operations, and I at the top. I start by lifting the boom, securing it to the prepared brackets to the mast using bolts, making sure to lock the bolt with a second nut. The arrow is supposed to be used for a long time, so the fasteners must be reliable. After the boom is installed, I begin lifting and installing the head. It’s getting dark, the weather is getting worse, I really want to finish it, so I continue. The operation is not complicated, the design allows you to simply put the headrest on the top of the mast, and secure it with a long bolt, from turning at the bottom of the headrest. This hole is prepared on the ground before the mast is raised. I also move the boom higher, from the mast to the head, so that it can be used to lift the antennas themselves. At the top, your hands get tired quickly, you need to hold on, and even perform manipulations... Phew, it seems that’s it, I’m going down!
All that remains is to tighten and secure the upper tier of guy ropes, finally check the alignment of the mast, and, if necessary, adjust the vertical using guy wires. We can stop here, I mean the work on installing the mast.
ANTENNA ASSEMBLY
The mast is ready, now comes the particularly enjoyable job of assembling the antennas. I start with a 40m antenna - N3L. I open the box, take out the contents, lay out the components, hardware, and elements in the required sequence. I was pleasantly surprised, the items were grouped and labeled, the small items were packaged, and instructions were included.
Although the seller supplied a complete kit for self-assembly, the documentation could be improved. After the first reading of the instructions, little things are not clear. I strain my brain a little, turn on the logic and-and-and... everything goes like clockwork! The traverse design consists of six sections of different diameters. Fastening is done using bolts. Places where pipes of the same diameter use auxiliary bushings. At the ends and in the middle part of the traverse, brackets are fixed, and elements are attached to them, through insulators, using clamps. It is these that I will “bait” immediately when assembling the BUM, so as not to waste time during the final assembly of the antenna.
I assemble the traverse, the sections are marked and the assembly directions are indicated, and I move in this sequence. The holes on the traverse sections (A,B,C,D,E,F) and bushings (J1,J2,J3) match “tightly”, it’s nice to work when there is no need to adjust
anything. I insert the bolts, tighten the nuts without straining, everything is quick and convenient. Now the mounting plates. They are assembled mutually perpendicular, with the help of U-shaped pins the BOOM is attached to the horizontal plate, and the pipe stand is similarly attached to the vertical plate.
It takes about twenty minutes to assemble the traverse. I check it again and put the semi-finished product aside. Next are the elements. It’s hard to make a mistake here, from the middle to the ends, everything is symmetrical, I build up the telescopic structure, and rivet it. I put on insulators for subsequent attachment to the BUM, I don’t connect the halves yet, I will do this during the final assembly of the antenna. I move on to the next one, collecting each subsequent one faster than the previous one. Another half hour and the elements are ready.
The site administration expresses gratitude to Igor Uvatenkov (RW9JD) for the material provided
