Subelement C: Receiving Systems – 10 Key Topics – 10 Exam Questions – 4 Drawings— Topic 23: Detectors - Video Amplifiers
Question 8-23C5
Element 8 (RADAR)Which of the following signals are usually an input to the video amplifier?
Explanation
A video amplifier's purpose is to boost the video signal to a level suitable for driving a display device (like a CRT or LCD). The signals controlling the display's appearance are either direct inputs to the amplifier or control its operation.
* **Contrast** controls the gain of the video amplifier. Increasing contrast increases the difference between the light and dark parts of the image by amplifying the video signal's amplitude swing.
* **Brilliance** (or Brightness) controls the overall light output of the display. This is typically achieved by adjusting a DC offset level applied to the video signal, which is then amplified, setting the baseline brightness.
* **Range**, especially in display systems like radar or oscilloscopes, refers to the sensitivity or scaling of the input signal. A "range" control effectively sets the amplitude of the input signal presented to the video amplifier for processing and display.
Since all three directly affect the characteristics of the signal that the video amplifier processes, or the way the amplifier processes it, they are considered inputs to the video amplifier's functionality.
Related Questions
8-23C3 In video amplifiers, compensation for the input and output stage capacitances must be accomplished to prevent distorting the video pulses. This compensation is normally accomplished by connecting:8-23C4 Which of the following signals is not usually an input to the video amplifier?8-23C6 The video (second) detector in a pulse modulated RADAR system would most likely use a/an:8-24C1 The AFC system is used to:8-24C2 A circuit used to develop AFC voltage in a RADAR receiver is called the: