4 1-28.   There are differences between low- and high-power transmitters.  The main difference is the high power transmitter contains a larger number of which of the following types of amplifiers? 1.   Oscillator 2.   Final power 3.   Intermediate power 4.   Intermediate frequency 1-29.   In an AM transmitter, audio frequencies are converted into corresponding electrical energy by which of the following components? 1.   An oscillator 2.   A microphone 3.   A modulator 4.   A headset 1-30.   In an fm transmitter, a varicap performs which of the following functions? 1.   It amplifies the outgoing signal 2.   It varies the oscillator frequency 3.   It demodulates the outgoing signal 4.   It multiplies the oscillator frequency 1-31.   If an oscillator has a fundamental frequency of 3,550 megahertz, what is the frequency of the third harmonic? 1.     5,325 megahertz 2.     7,100 megahertz 3.     9,875 megahertz 4.   10,650 megahertz 1-32.   If the fundamental frequency of an rf carrier is 1,000 kilohertz, what is the frequency of the fourth subharmonic? 1.   500 kilohertz 2.   333 kilohertz 3.   250 kilohertz 4.   200 kilohertz 1-33.   Oscillator output frequencies are raised to usable values by frequency multipliers.  To raise an oscillator frequency from 20 megahertz to 120 megahertz, what combination of frequency multipliers would be used? 1.   Two doublers 2.   A doubler and a tripler 3.   A doubler and a quadruplet 4.   A tripler and a quadruplet 1-34.   When an AM signal leaves the antenna of a transmitter, which of the following frequency components does the signal contain? 1.   The carrier 2.   The upper sideband 3.   The lower sideband 4.   All of the above 1-35.   In a single-sideband transmitter, selection of the desired sideband and suppression of the other is done by which of the following components? 1.   Mixer 2.   Filter 3.   Detector 4.   Oscillator 1-36.   When compared to a conventional AM signal, an ssb signal provides which of the following advantages? 1.   Improved frequency stability 2.   Increased receiver gain 3.   Reduced distortion 4.   Reduced bandwidth 1-37.   For ship-to-shore teletypewriter circuits, which of the following types of multiplexing is/are used? 1.   Time and/or phase 2.   Time and/or frequency 3.   Phase and/or modulation 4.   Frequency and/or modulation