Question
Physics Question on communication systems
The tank circuit used in a radio transmitter should have
A
high effective Q
B
low effective Q
C
loosely coupled load
D
Both (a) and (c)
Answer
Both (a) and (c)
Explanation
Solution
Harmonics and fundamental frequency voltages cross-modulate with each other producing fundamental frequency currents whose relation with the normal fundamental current vary with amount of harmonics in the oscillator circuit. The phase angle of the resultant fundamental frequency current thus varies resulting in frequency variation. Such frequency variation can be minimized by using a tank circuit having high effective Q having loosely coupled load.