Beat Frequency Oscillator: In this Beat Frequency Oscillator, the outputs of two RF oscillators are applied to a square law detector and the resulting difference frequency is amplified. The main advantage of this type of oscillator is that a stable continuous output covering the entire AF range can be realized by simple variation of the …
Vectrogram: This test instrument combines a keyed colour bar generator with an oscilloscope and is used for alignment and testing the colour section of a TV receiver. The amplitude and phase of the chrominance signal represents the colour saturation and hue of the scene. This information can also be displayed on the oscilloscope screen in …
Color Bar Pattern: Color Bar Pattern – The composite video signal at the output of a video detector consists of luminance Y signals, the chrominance signal, the color burst, sync pulses and blanking pulses. The amplitude of the video signal varies continuously due to the changing picture content, such a waveform is not useful for …
Video Test Pattern Generator: A pattern generator provides video signals directly, and with RF modulation, on standard TV channels for alignment, testing and servicing of TV receivers. The output signal is designed to produce simple geometric patterns like vertical and horizontal bars, checkerboard, cross-hatch, dots, etc. These patterns are used for linearity and video amplifier …
Marker Generator: Marker Generator – The sweep generator provides a visual display of the characteristics of the circuit or amplifier, but this is inadequate because it does not give any precise information of the frequency on the traced curve. For this, a separate RF generator, known as the Marker generator is used. This generator though …
Sweep Frequency Generator: Sweep Frequency Generator – An RF generator, when used for alignment and testing of the RF and IF stages of a TV receiver, permits recording of circuit performance at one frequency at a time. Therefore, plotting the total response curve point by point over the entire channel bandwidth becomes a laborious process …
Block Diagram of Sweep Generator: Block Diagram of Sweep Generator – It provides a sinusoidal output voltage whose frequency varies smoothly and continuously over an entire frequency band, usually at an audio rate. The process of frequency modulation may be accomplished electronically or mechanically. It is done electronically by using the modulating voltage to vary …
Random Noise Generator Block Diagram: A simplified Random Noise Generator Block Diagram used in the audio frequency range is shown in Fig. 8.8. The instrument offers the possibility of using a single measurement to indicate performance over a wide frequency band, instead of many measurements at one frequency at a time. The spectrum of …
Square and Pulse Generator Block Diagram(Laboratory Type): Square and Pulse Generator Block Diagram are used as measuring devices in combination with a CRO. They provide both quantitative and qualitative information of the system under test. They are made use of in transient response testing of amplifiers. The fundamental difference between a pulse generator and a …
Function Generator Block Diagram: A Function Generator Block Diagram produces different waveforms of adjustable frequency. The common output waveforms are the sine, square, triangular and sawtooth waves. The frequency may be adjusted, from a fraction of a Hertz to several hundred kHz. The various outputs of the generator can be made available at the same …