Category: Measurement Set up

Measuring Amplitude Modulation

Measuring Amplitude Modulation Using CRO: The CRO is widely used as an Measuring Amplitude Modulation. It presents the waveform for visual monitoring and is fairly accurate in measurements of modulation percentage. The type of CRO pattern observed depends on how the CRO is connected. The various patterns obtained are (i) wave envelope (ii) trapezoidal, and […]

Radio Frequency Modulation

Radio Frequency Modulation: Radio Frequency Modulation – The simplest method of measuring frequency deviation utilises an FM receiver with a BFO as the measuring instrument. The only coupling used is the air waves between the transmitting and receiving antenna, as shown in Fig. 16.16. In this setup, the modulating signal is replaced by a variable […]

Modulation Frequency Definition

Modulation Frequency Definition: Modulation Frequency Definition is the process of impressing information on a carrier wave by altering either its amplitude of frequency. In amplitude modulation, the degree is the percentage of amplitude change from the unmodulated value of the carrier. In Modulation Frequency Definition, the frequency deviation is the change in frequency in one […]

Audio Amplifier Frequency Response

Audio Amplifier Frequency Response: The Audio Amplifier Frequency Response is essential for filters, couplings circuits, amplifier stages and overall audio circuits. An amplifier stage is used as an example. A test setup for this amplifier stage is shown in Fig. 16.10. This measurement is used to determine the band of frequencies that this stage can […]

CCIF Intermodulation Distortion

CCIF Intermodulation Distortion: In the second method of carrying out an CCIF Intermodulation Distortion test, the two test signals used have equal amplitude, and relatively high but slightly different frequencies. When non-linear distortion is present, a difference frequency component appears in the output and is used as a measure of the amount of distortion present. […]

Nonlinear Distortion Measurements

Nonlinear Distortion Measurements: One of the methods of Nonlinear Distortion Measurements consists of simulta¬≠neously applying two sinusoidal voltages of different frequencies to the amplifier input and observing the sum, difference and various combination frequencies that are produced by the non-linearity of the amplifier. This method of Nonlinear Distortion Measurements is called the intermodulation method. The […]

Selectivity Measurement Receiver

Selectivity Measurement Receiver: The Selectivity Measurement Receiver is its ability to reject, (adjacent) unwanted signals. It is expressed as a curve, such as the one in Fig. 16.5, which shows the attenuation that the receiver offers to signals at frequencies near the one to which it is tuned. Selectivity is measured at the end of […]

Sensitivity Measurement Definition

Sensitivity Measurement Definition: The Sensitivity Measurement Definition of a radio receiver is its ability to amplify weak signals. It is often defined in terms of the voltage that must be applied to the receiver input terminals to give a standard output power, measured at the output terminals. For AM broadcast receivers, many of the relevant […]

RF UHF field strength meter circuit

RF UHF field strength meter circuit: There are two general methods available for determination of RF UHF field strength meter circuit. One is the standard antenna method. In this, use is made of an antenna in which the relationship between the field strength of the radio wave and the equivalent voltage that the wave induces […]

Simple Cylindrical Cavity Wavemeter

Simple Cylindrical Cavity Wavemeter: Resonant cavities find extensive use as wavemeter at microwave frequencies. They enjoy high accuracy, mechanical simplicity, and a large physical size in proportion to the wavelength being measured. Practical cavity wavemeter are always in the form of cylinders which are tunable by means of a piston that varies the length of […]