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| 1 | |
The process of translating a modulated signal to a higher or lower frequency while retaining all the originally transmitted information is |
| | A) | modulation |
| | B) | frequency division |
| | C) | frequency conversion |
| | D) | demodulation |
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| 2 | |
Frequency conversion which is a form of amplitude modulation is carried out by a mixer by a process known as |
| | A) | phasing |
| | B) | heterodyning |
| | C) | demodulating |
| | D) | multiplexing |
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| 3 | |
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Which of the following signals do not appear at the output of the mixer shown above? |
| | A) | input signal |
| | B) | audio signal |
| | C) | local oscillator signal |
| | D) | local oscillator signal plus input signal |
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| 4 | |
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What is the purpose of the tuned circuit shown above? |
| | A) | local oscillator |
| | B) | amplify RF signals |
| | C) | mix oscillator and input signals |
| | D) | select desired signal and reject all others |
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| 5 | |
Which of the following is not a benefit of using a frequency synthesizer over a simple VFO design? |
| | A) | output is locked to a crystal oscillator reference |
| | B) | incremental frequency changes |
| | C) | continuous frequency changes |
| | D) | local oscillator design is simple and inexpensive |
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| 6 | |
What is used to reduce image interference caused by crowding of the RF spectrum? |
| | A) | low-Q tuned circuits ahead of the mixer |
| | B) | high-Q tuned circuits after the RF amplifier |
| | C) | low-Q tuned circuits after the mixer |
| | D) | high-Q tuned circuits ahead of the mixer |
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| 7 | |
One way to obtain selectivity while eliminating the image problem is to use |
| | A) | a single-conversion superheterodyne receiver |
| | B) | a dual-conversion superheterodyne receiver |
| | C) | more tuned circuits |
| | D) | a TRF receiver |
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| 8 | |
A special version of the superheterodyne that converts the incoming signal directly to baseband is known as the |
| | A) | indirect conversion receiver |
| | B) | zero-IF receiver |
| | C) | dual-conversion receiver |
| | D) | special conversion receiver |
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| 9 | |
An electronic signal that is a mixture of many random frequencies at many amplitudes is |
| | A) | a harmonic |
| | B) | an overtone |
| | C) | noise |
| | D) | an infrared wave |
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| 10 | |
Which of the following indicates the relative strengths of the signal and the noise in a communication system? |
| | A) | signal-to-noise ratio |
| | B) | field strength |
| | C) | dB-to-noise factor |
| | D) | field level noise ratio |
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