RADIO RECEIVERS QUIZ

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

Inadequate selectivity at high frequencies

Gain variation over the frequency coverage range

Instability

Insufficient gain and sensitivity

TRUE ANSWER : ?
YOUR ANSWER : ?

Indicate the false statement in connection with communications receivers.

The noise limiter cuts off the receiver’s output during a noise pulse.

Variable sensitivity is used to eliminate selective fading

Double conversion is used to improve image rejection

A product demodulator could be used for the reception of Morse code.

TRUE ANSWER : ?
YOUR ANSWER : ?

The local oscillator of a broadcast receiver is tuned to a frequency higher than the incoming frequency

To help the image frequency rejection

Because otherwise an intermediate frequency could not be produced

To permit easier tracking

To allow adequate frequency coverage without switching

TRUE ANSWER : ?
YOUR ANSWER : ?

A superheterodyne receiver with an IF of 450 kHz is tuned to a signal at 1200 kHz. The image frequency is

1650 kHz

900 kHz

750 kHz

2100 kHz

TRUE ANSWER : ?
YOUR ANSWER : ?

If the intermediate frequency is very high (indicate false statement)

The selectivity will be poor

Tracking will be improved

The local oscillator need not be extremely stable

Image frequency rejection is very good

TRUE ANSWER : ?
YOUR ANSWER : ?

An AM receiver uses a diode detector for demodulation. This enables it satisfactorily to receive

Single-sideband, full-carrier

Single-sideband, suppressed-carrier

Single-sideband, reduced-carrier

ISB

TRUE ANSWER : ?
YOUR ANSWER : ?

Three-point tracking is achieved with

The padder capacitor

Double spotting

Double conversion

Variable selectivity

TRUE ANSWER : ?
YOUR ANSWER : ?

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

Its frequency stability is better

It is a simpler piece of equipment

It does not require crystal oscillator

It is relatively free of spurious frequency

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 : ?

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

Adjacent-channel rejection is more difficult

The transmission is not compatible with A3E

The receiver cannot use a phase comparator for AFC

Production of AGC is a rather complicated process

TRUE ANSWER : ?
YOUR ANSWER : ?