RADIO RECEIVERS QUIZ

In a broadcast superheterodyne receiver, the

Local oscillator frequency is normally double the IF

Mixer input must be tuned to the signal frequency

RF amplifier normally works at 455 kHz above the carrier frequency

Local oscillator operates below the signal frequency

TRUE ANSWER : ?
YOUR ANSWER : ?

The image frequency of a superheterodyne receiver

Is due to insufficient adjacent channel rejection

Is independent of the frequency to which the receiver is tuned

Is not rejected be the IF tuned circuits

Is created within the receiver itself

TRUE ANSWER : ?
YOUR ANSWER : ?

A low ratio of the ac to the dc load impedance of a diode detector results in

Poor AGC operation

Poor AF response

Diagonal clipping

Negative-peak clipping

TRUE ANSWER : ?
YOUR ANSWER : ?

The frequency generated by each decade in a direct frequency synthesizer is much higher than the frequency shown; this is done to

Reduce the spurious frequency problem

Increase the frequency stability of the synthesizer

Reduce the number of crystals required

Reduce the number of decades

TRUE ANSWER : ?
YOUR ANSWER : ?

Indicate which of the following statements about the advantages of the phase discriminator over the slope detector is false:

Better linearity

Greater limiting

Much easier alignment

Fewer tuned circuits

TRUE ANSWER : ?
YOUR ANSWER : ?

The controlled oscillator synthesizer is sometimes preferred over the direct one because

Its frequency stability is better

It is relatively free of spurious frequency

It does not require crystal oscillator

It is a simpler piece of equipment

TRUE ANSWER : ?
YOUR ANSWER : ?

Indicate the false statement. The superheterodyne receiver replaced the TRF receiver because the latter suffered from

Insufficient gain and sensitivity

Gain variation over the frequency coverage range

Inadequate selectivity at high frequencies

Instability

TRUE ANSWER : ?
YOUR ANSWER : ?

Indicate the false statement. Noting that no carrier is transmitter with J3E, we see that

The receiver cannot use a phase comparator for AFC

Production of AGC is a rather complicated process

The transmission is not compatible with A3E

Adjacent-channel rejection is more difficult

TRUE ANSWER : ?
YOUR ANSWER : ?

When a receiver has good blocking performance, this means that

Its image frequency rejection is poor

It is unaffected by AGC derived from nearby transmissions

It does not suffer from double-spotting

Its detector suffers from burnout

TRUE ANSWER : ?
YOUR ANSWER : ?

Show which of the following statements about the amplitude limiter is untrue:

When the input increases past the threshold of the limiting, the gain decreases to keep the output constant.

Leak-type bias must be used

The output must be tuned

The circuit is always biased in class C, by virtue of the leak-type bias.

TRUE ANSWER : ?
YOUR ANSWER : ?

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