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8-1 Monochrome TV working principle (black and white):

The TV signal that carries the composite visual signal and the audio signal enters through the antenna directed to the station, and these signals are transmitted through the feed line, which is the ribbon or coaxial cable that connects the antenna to the input of the device. The sections that the signal passes through are:

1- The voter: who is at the front or side of the device and tunes in manually or electronically on the required channel and contains:

A- RF Amplifier: Amplifies the RF radio frequencies of the station to which the device is tuned.

B - Local Oscillator: It generates frequencies that are higher than the frequency of the receiving channel by an average frequency (IF).

C - Mixer: It mixes the station's signal with the local oscillator's signal using the superheterodyne method. It excludes the frequencies resulting from the mixing and chooses the difference between the two frequencies, which is called the intermediate frequency (IF).

2 - Medium Frequency Amplifier: It consists of several stages that amplify the medium frequencies and get rid of unwanted frequencies by what is called wave traps.

3- Visual Signal Detector: (VIDEO) extracts image information from its carrier waves, which were capacitively modulated AM with the visual signal, including the audio signal, then modulated by FM frequency.

4 - Visual Signal Amplifier: The image signal is magnified and then directed to the screen valve.

E - the stage of the audio signal (sound): There are two ways to obtain the audio signal. The first is called the “separate sound” method, in which the audio signal is separated immediately after the voter stage. As for the second method, it is the (audio.common) method, in which the audio signal is separated from the visual detector stage, after it has accompanied the visual signal in the medium frequency amplification stages.

6 - Audio medium frequency amplifier stage.
7 - The audio signal detector works to extract and detect the audio signal modulated by the FM carrier wave.

8 - Audio frequency amplifier.

9 - the speaker. We will explain the work of these circuits in detail in the coming chapters.

10- The stages of synchronization and deviation: These include:

1- Synchronization and horizontal deviation (Horizontal), which include:

A- The separator and amplifier of the synchronization pulses from the composite visual signal after its exit from the visualization detector.

B - Separation circuit of horizontal synchronization pulses: It is a differential circuit and its frequency is (15625 Hz).

C - horizontal deviation generator.

d - horizontal deviation amplifier and high voltage generator in the high voltage transformer.

2 - Synchronization and Vertical Deflection: These include:

​​​​​​A - The vertical synchronization pulse separation circuit, called the integration circuit, and its frequency
50 Hz

b - vertical deviation generator;

C - Vertical deviation amplifier.

11- Electric current supply circuit, AC from the public network, or through a (12) (V) DC accumulator in small portable devices. The feeding circuit contains a circuit for rectification, filtering and filtration, and sub-voltage circuits that feed the phases of the television set, and it often has voltage regulation circuits.