مراحل جهاز الإستقبال الملون .. كتاب التلفزيون الملون والعادي

4-2 color receiver stages:

1 - antenna

2- Canal voter.

3- Medium frequency amplifiers for visuals

4 - Detector of the visual signal

e - Luminance amplifier.

6- Decoder unit.

7- Color screen valve.

8- The detector and amplifier of the audio signal.


9 - Horizontal and vertical synchronization stage.

10 - Horizontal and vertical deviation generator and amplifier.

11- Horizontal and vertical deviation files.

12 - Low Effort Nutrition Section.

13 - Department of nutrition and voltages of the high voltage transformer.

4-3 Antenna:

He is the one who receives the radio (electromagnetic) waves that are spread in places near and far from the stations, which are broadcast by these television stations and others. The antenna may be internal to the device. Especially small mobile devices, with which only nearby or strong transmitting stations can be received. As for the external antenna It is installed in a high, exposed place, away from other antennas, beams, and tall buildings that obstruct the signal path. It is stronger in reception and clearer signal whenever it is consistent in its measurements and orientation with: the transmitting station and away from the sources of interference that generate electromagnetic waves such as (compiler and coal motors - electrical stations - motorways...) the antenna is directed towards the transmitting station or the relay station directly, according to Line of sight. Modern antennas are equipped with a motor that directs them from inside the house to move them in the best direction. Some modern TV sets may have a circuit that automatically directs the antenna to pick up the strongest signal for the desired station.

The presence of tall buildings, hills, or berms in the way of the signal or close to the antenna creates ghosting and shadows in the image and weakens its clarity, because the signal is reflected off this high object. The direct signals are then connected to the antenna, and then the reflected signal, as in Figure (4-6).