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1192081 Pages:2

Explain the working of a balanced modulator using FET. Derive the expression for
its output voltage.
What are the drawbacks of a tuned radio frequency (TRF) receiver? With the
block diagram of a super-heterodyne receiver, explain that they do not suffer from
these drawbacks.
What is companded SSB?

PART ட

Answer any two full questions, each carries 20 marks.

With the help of a circuit diagram, explain the working of a JFET reactance
modulator.
Explain the concept of pre-emphasis and de-emphasis with the help of circuit
diagram, and frequency response curves.
Explain Armstrong method of FM generation.
With necessary curves and circuit diagrams, explain the working of FM slope
detector and balanced detector.
With the help of circuit diagram, explain the working of a varactor diode
modulator.
What are the basic functions of a telephone set?

Explain the set of procedures for completing a local telephone call.

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