The TV has turned into an indispensable element of a modern apartment. This device should differ not only harmoniously fit into the interior, but also create a high-quality image of the received transmission. Sometimes it happens that the TV shows poorly. The easiest way to solve this problem is to call a TV technician, but not everyone can afford it, and you have to specially wait for the arrival of a specialist.
In most cases, the problem of poor image can be solved on your own with a minimal understanding of signal transmission processes. The following is a description of several simple procedures, the full or partial implementation of which allows you to achieve a high-quality image with a 90% probability.
All the steps described below do not require the use of measuring instruments and are based on two main steps:
- comparing the existing wiring with a known good line.
- identifying an internal malfunction by visual inspection of the entire line from the antenna output to the television input.
After that, the corresponding repairs are carried out.
1. Checking the serviceability of the house part of the television wiring
First, make sure that the problem is inside the house wiring. To do this, it is enough to connect the access splitter or the antenna output directly to the antenna input of the TV with a coaxial cable. When a normal image is obtained, the source of the problem lies within the wiring.
2. Short circuit in detachable connectors
The signal on the way from the antenna output to the TV can pass through several connectors: at the antenna output, in places of installation of splitters, at the point of extension using a coaxial feed-through adapter, picture 1. Careless installation of the cable part of the detachable connector of the braid wires may touch the center core, which immediately leads to a drop in the signal level and unstable image reception.
This malfunction is revealed by visual inspection of all detachable connections in the path.
3. Cable jam
Another reason for a short circuit is a cable "kink", as a result of which the central core pushes the insulation and reaches the braid. It can appear as a result of careless laying, and during operation as a result of excessive bending. Clamps by a door, chair, etc. are very similar in consequences.
Also detected by inspection. The best way to repair a damaged cable is to replace it with a new one.
4. Old antenna cable
If the antenna cable has served for three or more decades, then it should be replaced with a new one. The need for this procedure is due, again, to the aging of the dielectric plastic, which separates the center wire and the braid. Due to a change in its properties, the attenuation of the cable begins to noticeably increase, which leads to a loss of image quality.
5. No contact in the plug
Another weak polymer element of the wiring is the plastic of the Soviet-made antenna plugs. It also ages, becomes brittle and breaks easily with little effort, resulting in loss of contact.
In addition, even an externally sound plug can lose contact with the cable along the core or braid if it is violently pulled out.
In this situation, the old plug must be replaced with a new threaded F-connector, Figure 2. It simply wraps around the cable over the braid. The excess center wire is cut off with side cutters.
6. Large branching ratio
To connect several TVs to one antenna, splitters are used, an example of which is shown in Figure 3. Each such device introduces certain losses into the transmission path, too large of which affects the image quality. If it turns out to improve the quality of reception by excluding the splitter from the path and bringing the signal to TV using the pass-through adapter mentioned above, then you should switch to an active splitter, Figure 4. It differs from its passive counterpart by the presence of a built-in amplifier, which helps to solve the problem of a low signal level.