Sensitivity & Drawbacks of Tuned Radio Receiver
Drawbacks of Tuned Radio Receiver are
a) Oscillate at higher frequencies
b) Selectivity is poor
c) Bandwidth of the TRF receiver varies with incoming frequency
d) All of the above
Correct Answer: d) All of the above
The TRF receivers give unstable output as they have the tendency to oscillate at higher frequencies. The selectivity of the TRF receivers is poor to distinguish the desired signal from the undesired signal. With tuning range, there is variation in bandwidth with incoming frequency. The receiver selects adjacent undesired frequencies with the desired frequencies due to variable bandwidth.
Sensitivity is defined as
a) Ability of receiver to amplify weak signals
b) Ability to reject unwanted signals
c) Ability to convert incoming signal into Image Frequency
d) Ability to reject noise
Correct Answer: a) Ability of receiver to amplify weak signals
Sensitivity of a receiver is defined as the ability of the receiver to amplify weak signals received by the receiver. It is the voltage that must be applied at the input terminals of the receiver to achieve a minimum standard output at the output of the receiver. The sensitivity is expressed in micro volts or Decibels. The typical value of sensitivity is 150μV for small broadcast band receiver.