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Radio Receivers - Engineering

Q1:

As compared to tuned radio frequency receivers which of the following is the advantage of using superheterodyne receivers?

A High gain and better sensitivity

B Better selectivity at high frequencies

C Stability

D Noise suppression

ANS:A - High gain and better sensitivity

In, Superheterodyne the reciever here are the sections ARMIDAS.

= Antenna Rf(amplifier) Mixer If(amplifier) Demodulator or detector Af amplifier Speaker.

In the superheterodyne the If section consists of a series of If amplifiers and bandpass filter
bandpass filter = only desired or required frequency can allow to enter and reject other frequency and all signal frequencies are converted typically to a constant lower frequency before detection the IF center frequency and bandwidth are constant for all stations, the standard IF frequency which is 455khz.

While in the Tune Radio Frequency the sections are
ARDAS = Antenna Rf(amplifier) Demodulator Af(amplifier) Speaker
TRF receivers suffered from poor selectivity, since even filters with a high Q factor have a wide bandwidth at radio frequencies, with multi stage amplifiers TRF also have no IF stage.