Question

With the functional block diagram explain the working of a monochrome TV transmitter.

Answer 1

Hint: Monochrome TV transmitter consists of a television camera, video amplifier, AM modulating amplifier, audio amplifier, FM modulating amplifier, FM sound transmitter, crystal oscillator, RF amplifier, power amplifier, Scanning and synchronizing circuits, Transmitter antenna, microphone and Combining network.

Complete step by step answer:
Television is formed by combining two words: tele and vision. It means to see the picture which are telecasted from a long distance. It is a telecommunication medium used for transmitting images and sound. These images can be monochrome i.e. black and white or color.

The above figure shows the functional block diagram of a monochrome TV transmitter. It consists of a television camera, video amplifier, AM modulating amplifier, audio amplifier, FM modulating amplifier, FM sound transmitter, crystal oscillator, RF amplifier, power amplifier, Scanning and synchronizing circuits, Transmitter antenna, microphone and Combining network.
In TV transmission, both sound and picture are transmitted. AM Modulators are used for picture while FM Modulators are used for sound.
In Monochrome Tv transmission, scanning and synchronizing circuits produce sets of pulses for providing pulses for proper functioning of TV systems. Scanning and Synchronizing circuits includes wave generating and shaping circuits. Examples of these circuits are Multivibrator circuits, clipping circuits etc.
The output signal of a camera tube corresponding to the image to be screened on the television is amplified through the video amplifier stage. The image signals together with the synchronizing pulses are raised to a level for modulating RF carrier waves generated in the RF channel. The crystal oscillators are used to generate allotted picture frequency. Then the wave output is amplified and then fed to the power amplifier.
The microphone converts the sound related to the image being screened into proportional electrical signal. Then the audio signal from the microphone is amplified. After amplification, the audio signal is frequency modulated.
The outputs from picture signal transmitter and sound signal transmitter are combined through a combining network and then fed to a common transmitter antenna for transmission.

Note: The signals received by Transmitter antennas are in the form of electromagnetic waves. Working of monochrome TV transmitters and color TV transmitters are quite different. Similarly working of receivers is also different from that of transmitters. So try to understand their working rather than memorizing them.