I already once wrote about the repair of antennas, it was about restoring the tip of the antenna. But there are worse cases when this tip has nothing to cling to, that is, there are no whole antenna links. In fact, they can say that here is another problem, why repair the antenna when you can buy a new one and put it in place of the defective one.
Well, firstly, try to find these antennas first, something I don’t see them for sale at all lately.
Secondly, if you find it, it will most likely be a Chinese remake with thin-walled tubes, breaking which is a couple of trifles, put forward and pushed in incorrectly, and it broke.
Thirdly, even if you buy an antenna, it will be the fastest with short links, however, many old radios were equipped with antennas with very long links. Of course, you can also move the short links apart, but if you think like that, then you can allow the installation of half of the television horns, or even screw the wire in general. But I prefer to have an antenna as close to my own as possible.
Well, I got it for repairs. Sanyo, he initially had a long three-link antenna, the third, thinnest link was broken off under the very spine, and the spine itself was hidden in the depths of the middle link.

In general, the third link should have been extended to such a distance, and the second should protrude in the folded state by only a couple of millimeters from the thickest link. But in this case, the antenna will not reach all the way and therefore will hang out.

When I change a broken antenna to a working one, I don't throw away the old one. Sometimes she may be needed as a donor.

I picked up a tube of suitable diameter, which will serve as the third link in the repaired antenna. However, despite the fact that the tube fits perfectly into the antenna from the outside, there is no way to install it in the antenna so that it does not pop out later when unfolded, so you cannot do without complete disassembly of the antenna.
To do this, you first need to separate the shank. The best option for this is to cut the tube along the ring farthest from the shank. You will not be able to flare, do not waste your time.

Unfortunately, the thickest link after that will be shorter by 5-6 mm, this sacrifice will have to be accepted. There will be a piece of tube on the shank that will have to be removed.

The easiest way to clean the shank is with nippers, holding it by the flat part with pliers.

Sometimes the flat part of the shank is bent. It should be straightened with care, because it can be broken off at once. It's such a brittle metal. If the bend is not very strong, then it is better not to touch it.

Using a thin screwdriver or a thin needle, push the thinner tube out of the thicker one, try not to lose the brass gaskets that prevent the antenna links from popping out. They will come in handy during assembly.

Be sure to push out the remnants of the broken one from the last whole link, firstly, this piece will prevent you from installing a new link, and secondly, you will need its brass gaskets if you do not have extra ones in stock.

The antenna is assembled in the reverse order, starting from the thinnest link. Install brass spacers so that their protrusions fall into the holes on the sides of the tube.

In general, the task is not difficult, especially for a three-section antenna. There are short multi-link ones, with those more hassle.

Now you need to insert the shank and secure it. You can roll the shank in the tube, but at home, rolling can turn out to be a little aesthetic. What will you roll it with, except with wire cutters? In addition, the antenna can also hang on the shank if you have not rolled it hard enough.
Some people, I've been told, glue it on. For me, this is wrong, the glue is a dielectric and it’s not a fact that somewhere you will definitely have a touch through the metal, an example of cold soldering, when the wire is surrounded on all sides by solder and yet there is no contact between them, more than common.
I prefer to solder the shank. To do this, I clean a few points on it, and lightly tinker.

With the help of flux, I service the inside of the antenna tube.

Then I warm up the shank with a finger and insert it inside the tube. The connection is more than reliable.

Car antennas have long been considered an everyday accessory, but such equipment often breaks down, often it is simply stolen. Factory models are quite expensive, and it is often problematic to find the right one. However, you can make auto antennas for the radio with your own hands. The process is simple, but requires some professional skills.

The range of devices in stores is very large. According to the purpose, this technique is divided into the following types:

1. Active antennas for the car radio when the signal is received along with the built-in amplifier. They are considered very powerful. Great for picking up signals over long distances.
2. passive models. They work without amplifiers. Considered simpler, they are much easier to make yourself. Such devices are just recommended to be installed if car radios are used only in the vicinity of the city.

Antennas are classified according to the installation method. Distinguish between internal and external antennas:

1. Internal. They are mounted in car interiors. This installation method is suitable for active models.
2. External. They are located outside the car bodies. This installation is more suitable for passive devices. At the same time, the low power of the technique is somehow compensated.

To make an antenna for a car radio with your own hands, you need to take into account the principles of operation of the signal catcher, determine the length of the device, its location, and the degree of complexity of the entire structure.

Conventional car antennas are quarter-wave vibrators that are grounded to car bodies. Such devices can only be mounted vertically, and reach a length of 2.5 m. For antennas of standard car radios, these parameters are considered redundant.

That is why, to replace obsolete overall devices, self-made external antennas for car radios are used. To hear stable radio signals in the popular range, it is enough to use pin devices with a length of 10 to 20 cm.

In addition to significant cost savings, there are a number of other advantages in using this technique. The following advantages stand out:

1. A self-made design can be customized to fit perfectly different models cars.
2. There will be no problem with the installation height for receiving radio signals.
3. Installing a homemade device is much easier than factory counterparts.
4. It is possible to improve the quality of signal reception with the correct production of the installation, in contrast to the use of purchased antennas.

It is worth noting that you can start independent design if you have skills in working with electrical engineering, otherwise it is better to use the services of professionals or use store counterparts.

You can make both inactive and active (with an amplifier) ​​devices with your own hands. The production technology consists of several stages:

• training necessary tools;
• direct assembly;
• fastening to the machine body;
• connections.

Assembling different types of antennas for a radio tape recorder with your own hands differs significantly even in the selection of the necessary tools.

Passive antennas without an amplifier are considered to be quite simple in their design. To create such a device, you will need:

• copper wire (diameter from 1.5-2 mm);
• quality nut;
• a good file;
• screwdriver;
• thermal glue (can be replaced with heat shrink tubing);
• screw (diameter M5);
• lock-nut.

Assembly is carried out in stages. For this:

To give an aesthetic appearance to the installation, a film is glued on it, treated with a primer, and painted. The passive device is ready.

Creating an Active Fixture View

A feature of this technique is the presence of equipment that enhances signal reception. When creating internal active installations, frame structures are used. This requires the following tools:

• copper wire, always with insulation (diameter - 2 mm);
• home amplifier (a TV device will do);
• high-quality soldering iron;
• connector that is suitable for the radio;
• good cutters;
• glue.

An amplifier case designed for a conventional home antenna is often used as the basic basis for the device. Solder a wire to it, which, in turn, will be connected to the radio. This is necessary for the amplifier to receive and transmit signals.

An antenna plug is connected to the socket, a connector is mounted on the other end of the wire. The power cable for the amplifier in car radios is considered a control cable, it is colored blue.

An active type receiver is mounted on the roof of the car so that signals are well received. To do this, two holes are drilled in the body - mounting and auxiliary. The antenna wire is laid along the perimeter of the driver's door, fixing with glue. After installation on the roof of the car, they fix the cable (side) in the rack, carefully connect it to the car radio.

Features of installation and connection

Traditionally active types antennas for radio tape recorders are installed on windshields in the upper right corners or behind rear-view mirrors. Passive installations for receiving signals are placed on car bodies, usually mounted on roofs.

Any antenna is mounted only on a clean surface. For installation, use glue or masking tape, bolts, nuts, locknuts for grounding, a drill that is suitable for the diameter of the antenna wire. The mounting site must be degreased with a special cleaner.

Fix the devices with glue or masking tape. After installation, wires are laid from the antenna to the radio. This is done either around the perimeter of car doors or windows, or directly through the cabin through special holes.

There are three wires in the design of an ordinary car antenna:

Most often, the second wire is combined with the third, connecting the power, activate contact function, the antenna begins to receive a signal.

It is important to choose the right place to install the antenna. A car body can be both a kind of indicator of improving the quality of signal reception, and a hindrance. The best place for fastening is the center of the roof.

Near the catcher should not be foreign objects made of metal. Combined antennas for receiving various communication signals are best purchased ready-made.

The installation must be protected as much as possible from impact. external environment so that the contacts do not oxidize, the details of the entire structure do not rust.

Antenna made by hand effective method savings, improving the quality of signal reception, the possibility of technical refinement of the radio in your own car.

Usually self-repair of antennas is more about tuning. Radio amateurs are aware of the parameters that require adjustment. In particular this applies homemade devices to receive a signal. For example, the ideal SWR is equal to one, in the descriptions of the self-assembly of the antenna you will see either an a priori calculation of this parameter, or instructions on how to adjust the dimensions and circuit using an SWR meter. Such an approach will allow reducing signal losses to the first amplifying stage, therefore, the sensitivity of the receiving device (the range of the transmitter) is increased. In practice, this means an increase in the quality and distance of a confident capture of stations and walkie-talkies. This is important for the terrestrial antenna.

Soldering

Today, soldering is an optional step. Shrink wrap will help restore the integrity of the telescopic antenna (without the possibility of folding). Take the trouble to ensure reliable contact at the fault. To solder steel, buy a special acid for cleaning the surface.

Antenna tuning

Phrases repair sound funny collective antenna or repair antennas with your own hands. These are passive devices that do not require professional maintenance. If a child breaks, repair telescopic antenna, tin ends, solder. detailed instructions is not required, any man (boy) can repair the antenna on his own.

Regardless of the incoming signal, the wave is characterized by frequency and polarization. Two aspects determine the design of the antenna. The power of the incoming signal also makes adjustments. Depending on the data, the question of the required amplification is decided, whether to obtain it due to directional properties or an amplifying stage.

Let's make a reservation that the sensitivity of the receiving device is the minimum signal level caught by the equipment. Of course, the lower the field strength at which the broadcast program is heard with confidence, the better. The sensitivity depends on the signal loss to the first amplifier. After that, the attenuation is not so critical anymore. For this reason, they try to make the feeder between the antenna and the receiving device as short as possible. For the stated purposes, the SWR is minimized. In this case, the power passes to the feeder. The concept of coordination is known, the term is closely related to the mentioned parameter. Ideally, the impedance of the devices in the circuit is the same. The antenna is made at 75 ohms, the cable at 75 ohms and the receiver at 75 ohms. If the link is knocked out of the row, matching devices are used. Quarter-wave transformers, U-loops, line segments.

How to increase the signal level. Take care to aim the antenna correctly. The dish should look at the satellite. On the ground it is more difficult. There is a concept - a re-reflected signal. Not the fact that the direction to the station will give a maximum of confident reception. The main power can come from an arbitrary azimuth and elevation, it is worth suffering in search of the right solution. People outside the radio are surprised why the receiver catches better in the corner of the room than at the window, in fact, it’s simple - in the window sill area there are no trajectories of a favorable alignment of the superposition of fields. In simple terms, this means that the waves add up in an incredible way, giving an amazing picture.

This is incomprehensible to a beginner, let us explain: if at a given point in space two strong signals add up in antiphase, we get zero. A pair of weak beams can give much best effect if the wave is coherent. If a person could see radio waves, the room would be dotted with gaps and bright places, like a playful wave of the sea reflected on a rock. The picture will not be permanent at all. Any cloud, rain, wind will affect the result. For this reason, it is far from always enough to aim and adjust the antenna once for constant reliable reception.

Features of setting up satellite dishes

Better with satellites. Tricolor TV antennas aim once and for all. The bracket is supplied with several sets of bolts for the indicated purposes. It is enough to tighten it properly to ensure the right direction for years. Note that broadcasting satellites are geostationary. From the surface of the Earth, they appear to be motionless. This is possible when the spacecraft completes exactly one orbit in 24 hours. You will receive the indicated alignment by moving the satellites over the equator at an altitude of 20,000 km. Exact figures are not very important, the main thing is to understand that broadcasting devices hang above the equator at the same height, there is no same azimuth for two different satellites.

A galaxy of spacecraft writes an arc in the sky with a long-calculated shape. Therefore, it becomes possible to catch a lot of programs on a plate. To achieve the goal, an arc is set, with hung emitters. As a result of the laws of reflection, each converter receives one satellite. It is important to correctly maintain the polarization (horizontal or vertical, in Russia there is also a circular one).

Many understood what the conversation was about. Inside the converter is a depolarization plate. Take the trouble to put it slightly differently to change the parameter in the desired direction. To receive the right polarization, the tilt is 45 degrees to the side relative to the vertical axis of symmetry of the feed, in the case of the left, the indentation is in the opposite direction. The question arises, why fence the garden. There are several answers here. Other experts believe that in the Russian Federation circular polarization is accepted as a tribute to the technologies of the USSR. In the past, it was customary to build non-geostationary spy satellites. Then, with linear polarization, reception on the ground is difficult, the plane sometimes tilts at an unpredictable angle. The use of the circular indicated difficulties solved - it only remained to aim the dish at the trajectory of the spacecraft.

The tilt plane of linear polarization is additionally influenced by at least two factors:

1. The position of the satellite in the sky. It has already been said that spacecraft are scattered in an arc. Satellites near the horizon are seen slightly tilted. You have to more accurately aim the irradiator relative to the dish and tilt it as needed.
2. The Faraday effect is known: an electromagnetic wave rotates in the constant field of the Earth. This leads to a tilt of the plane of polarization, it is difficult to calculate the choice in advance. You will have to experimentally twist the converter, setting up a satellite dish.

Plates vary in diameter. The focal length corresponds to the opening angle of the irradiator, otherwise the reception becomes uncertain or is eliminated. A large opening combined with a small plate looks silly. In theory, feeds should be placed in the focal plane. Rays that come in parallel from a certain direction intersect here. To achieve the result, special guides are sold where converters are strung.

When repairing the Tricolor antenna and adjusting it, it is useful to use special devices. For example, Satellite Finder. The device is switched on between the receiver and the antenna, it beeps more piercingly as the signal level increases, when the master rotates the dish around. First, the correct position of the antenna is achieved, then it is the turn to adjust the position of the feeds. This is where the information provided in this article comes in handy. Find the correct slope experimentally. The work is easier to do together, focusing on the satellite search program built into the receiver. The process is tedious and long, but effective.

Let's add about ranges. C usually uses linear polarization, while Ku uses linear polarization. We have already talked about the Faraday effect, at high frequencies it appears less. Broadcasting in Ku is predominantly linear. The depolarizer converts circular polarization to linear polarization, but does the same with linear polarization. For correct setting it's important to know:

• The depolarization plate is made of a dielectric.
• Thickness, length, shape affect the reception quality.

• The composition of the depolarizer includes steel pins, visible when looking into the irradiator. There are two triggers - vertical and horizontal.
• In order for the converter to receive both C and Ku bands at the same time, you need to buy a combined model. It will not be possible to receive on a simple irradiator.

Combined antenna converters will begin to lose part of the signal, the same is observed if two are placed side by side, one per range. Ideal solution no, it is possible to fight:

1. A combined antenna feed without a plate is taken.
2. A tee is cut into the feeder, feeding separately two receivers (one per range) and two TVs.
3. According to the testimony of technology, the position of the antenna is located, where the signal is maximum.
4. The selection of the material, size and position of the depolarization plate begins. Not the fact that the best option will be the factory, do not forget to tilt the irradiator, as described above.

As a result, there is a chance to find a position in which both ranges will manifest themselves in the best way. This means that the repair of the TV antenna ended with a positive result.