Audio and Data Moulds

In MODCOM-5, some of the angle modulation techniques currently usedin modern analog and digital communications systems are studied.An analog or digital information signal is conveyed on to acarrier signal whose instantaneous angle or frequency varies according to the variation of the original information signal. Although angle or exponential modulation usually requires more bandwidth than linear modulation, it offers the advantage of increasedsignal to noise ratio without increases in transmitter power. Specifically, Phase Modulation (PM) and conventional Frequency (FM)will be studied as well as modulation and demodulation techniques.Modulated speech and data signals are measured in both the time and frequency domain using the PU-400 interface to the personal computer. The PU-410 RF service unit supplies the necessary signal sources and other measuring circuits.Module DescriptionThe Angle Modulation and Demodulation module MODCOM-5 providesa number of communication functions that enable the student to perform meaningful and interesting experiments.MODCOM-5 consists of the following:Audio differentiator Audio pre-emphasis VCO/FM modulator Audio integrator RF controlled switch Quadrature detector Frequency discriminator Zero Crossing detector RF limiter Phase locked loop (PLL) Audio de-emphasis Recommended Experiments1. Phase Modulation2. Correlation of PM and FM3. Analog FM4. Digital FM5. FM Detectors6. FM Demodulation For Strong Signal & Noise7. FM Demodulation For Weak Signal & Noise8. PLL as an FM Detector