Questions - Receiver Operation

Question file 17

      STUDY NOTES     QUESTIONS WITHOUT ANSWERS 

    1. The frequency stability of a receiver is its ability to:
      1. stay tuned to the desired signal
      2. track the incoming signal as it drifts
      3. provide a frequency standard
      4. provide a digital readout
      ========= Answer is a =========
    2. The sensitivity of a receiver specifies:
      1. the bandwidth of the RF preamplifier
      2. the stability of the oscillator
      3. its ability to receive weak signals
      4. its ability to reject strong signals
      ========= Answer is c =========
    3. Of two receivers, the one capable of receiving the weakest signal will have:
      1. an RF gain control
      2. the least internally-generated noise
      3. the loudest audio output
      4. the greatest tuning range
      ========= Answer is b =========
    4. The figure in a receiver's specifications which indicates its sensitivity is the:
      1. bandwidth of the IF in kilohertz
      2. audio output in watts
      3. signal plus noise to noise ratio
      4. number of RF amplifiers
      ========= Answer is c =========
    5. If two receivers are compared, the more sensitive receiver will produce:
      1. more than one signal
      2. less signal and more noise
      3. more signal and less noise
      4. a steady oscillator drift
      ========= Answer is c =========
    6. The ability of a receiver to separate signals close in frequency is called its:
      1. noise figure
      2. sensitivity
      3. bandwidth
      4. selectivity
      ========= Answer is d =========
    7. A receiver with high selectivity has a:
      1. wide bandwidth
      2. wide tuning range
      3. narrow bandwidth
      4. narrow tuning range
      ========= Answer is c =========
    8. The BFO in a superhet receiver operates on a frequency nearest to that of its:
      1. RF amplifier
      2. audio amplifier
      3. local oscillator
      4. IF amplifier
      ========= Answer is d =========
    9. To receive Morse code signals, a BFO is employed in a superhet receiver to:
      1. produce IF signals
      2. beat with the local oscillator signal to produce sidebands
      3. produce an audio tone to beat with the IF signal
      4. beat with the IF signal to produce an audio tone
      ========= Answer is d =========
    10. The following transmission mode is usually demodulated by a product detector:
      1. pulse modulation
      2. double sideband full carrier modulation
      3. frequency modulation
      4. single sideband suppressed carrier modulation
      ========= Answer is d =========
    11. A superhet receiver for SSB reception has an insertion oscillator to:
      1. replace the suppressed carrier for detection
      2. phase out the unwanted sideband signal
      3. reduce the passband of the IF stages
      4. beat with the received carrier to produce the other sideband
      ========= Answer is a =========
    12. A stage in a receiver with input and output circuits tuned to the received frequency is the:
      1. RF amplifier
      2. local oscillator
      3. audio frequency amplifier
      4. detector
      ========= Answer is a =========
    13. An RF amplifier ahead of the mixer stage in a superhet receiver:
      1. enables the receiver to tune a greater frequency range
      2. means no BFO stage is needed
      3. makes it possible to receive SSB signals
      4. increases the sensitivity of the receiver
      ========= Answer is d =========
    14. A communication receiver may have several IF filters of different bandwidths. The operator selects one to:
      1. improve the S-meter readings
      2. improve the receiver sensitivity
      3. improve the reception of different types of signal
      4. increase the noise received
      ========= Answer is c =========
    15. The stage in a superhet receiver with a tuneable input and fixed tuned output is the:
      1. RF amplifier
      2. mixer stage
      3. IF amplifier
      4. local oscillator
      ========= Answer is b =========
    16. The mixer stage of a superhet receiver:
      1. produces spurious signals
      2. produces an intermediate frequency signal
      3. acts as a buffer stage
      4. demodulates SSB signals
      ========= Answer is b =========
    17. A 7 MHz signal and a 16 MHz oscillator are applied to a mixer stage. The output will contain the input frequencies and:
      1. 8 and 9 MHz
      2. 7 and 9 MHz
      3. 9 and 23 MHz
      4. 3.5 and 9 MHz
      ========= Answer is c =========
    18. Selectivity in a superhet receiver is achieved primarily in the:
      1. RF amplifier
      2. Mixer
      3. IF amplifier
      4. Audio stage
      ========= Answer is c =========
    19. The abbreviation AGC means:
      1. attenuating gain capacitor
      2. automatic gain control
      3. anode-grid capacitor
      4. amplified grid conductance
      ========= Answer is b =========
    20. The AGC circuit in a receiver usually controls the:
      1. audio stage
      2. mixer stage
      3. power supply
      4. RF and IF stages
      ========= Answer is d =========
    21. The tuning control of a superhet receiver changes the tuned frequency of the:
      1. audio amplifier
      2. IF amplifier
      3. local oscillator
      4. post-detector amplifier
      ========= Answer is c =========
    22. A superhet receiver, with an IF at 500 kHz, is receiving a 14 MHz signal. The local oscillator frequency is:
      1. 14.5 MHz
      2. 19 MHz
      3. 500 kHz
      4. 28 MHz
      ========= Answer is a =========
    23. An audio amplifier is necessary in a receiver because:
      1. signals leaving the detector are weak
      2. the carrier frequency must be replaced
      3. the signal requires demodulation
      4. RF signals are not heard by the human ear
      ========= Answer is a =========
    24. The audio output transformer in a receiver is required to:
      1. step up the audio gain
      2. protect the loudspeaker from high currents
      3. improve the audio tone
      4. match the output impedance of the audio amplifier to the speaker
      ========= Answer is d =========
    25. If the carrier insertion oscillator is counted, then a single conversion superhet receiver has:
      1. one oscillator
      2. two oscillators
      3. three oscillators
      4. four oscillators
      ========= Answer is b =========
    26. A superhet receiver, with a 500 kHz IF, is receiving a signal at 21.0 MHz. A strong unwanted signal at 22 MHz is interfering. The cause is:
      1. insufficient IF selectivity
      2. the 22 MHz signal is out-of-band
      3. 22 MHz is the image frequency
      4. insufficient RF gain
      ========= Answer is c =========
    27. A superhet receiver receives an incoming signal of 3540 kHz and the local oscillator produces a signal of 3995 kHz. The IF amplifier is tuned to:
      1. 455 kHz
      2. 3540 kHz
      3. 3995 kHz
      4. 7435 kHz
      ========= Answer is a =========
    28. A double conversion receiver designed for SSB reception has a carrier insertion oscillator and:
      1. one IF stage and one local oscillator
      2. two IF stages and one local oscillator
      3. two IF stages and two local oscillators
      4. two IF stages and three local oscillators
      ========= Answer is c =========
    29. An advantage of a double conversion receiver is that it:
      1. does not drift off frequency
      2. produces a louder audio signal
      3. has improved image rejection characteristics
      4. is a more sensitive receiver
      ========= Answer is c =========
    30. A receiver squelch circuit:
      1. automatically keeps the audio output at maximum level
      2. silences the receiver speaker during periods of no received signal
      3. provides a noisy operating environment
      4. is not suitable for pocket-size receivers
      ========= Answer is b =========