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1993-03-09
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224H-2.1 D 8-2 Key word amplitude, ie.|amplitude modulation
What is the term for alteration of the amplitude of an
RF wave for the purpose of conveying information?
A. Frequency modulation
B. Phase modulation
C. Amplitude rectification
D. Amplitude modulation
*
225H-2.3 B 8-8 Key word phase, ie.|phase modulation
What is the term for alteration of the phase of an
RF wave for the purpose of conveying information?
A. Pulse modulation
B. Phase modulation
C. Phase rectification
D. Amplitude modulation
*
226H-2.4 D 8-8 Key word frequency, ie.|frequency modulation
What is the term for alteration of the frequency of an
RF wave for the purpose of conveying information?
A. Phase rectification
B. Frequency rectification
C. Amplitude modulation
D. Frequency modulation
*
227H-3.1 D 8-3 Key word amplitude, ie.|amplitude modulation
In what emission type does the instantaneous amplitude (envelope)
of the RF signal vary in accordance with the modulating AF?
A. Frequency shift keying
B. Pulse modulation
C. Frequency modulation
D. Amplitude modulation
*
228H-3.2 A 8-3 Each sideband bandwidth is equal to |the highest audio frequency modulating|the transmitter
What determines the spectrum space occupied by each group of
sidebands generated by a correctly operating double-sideband
phone transmitter?
A. The audio frequencies used to modulate the transmitter
B. The phase angle between the audio and radio frequencies
being mixed
C. The radio frequencies used in the transmitter's VFO
D. The CW keying speed
*
229H-4.1 C 8-6 Forty dB minimum
How much is the carrier suppressed in a single-sideband phone
transmission?
A. No more than 20 dB below peak output power
B. No more than 30 dB below peak output power
C. At least 40 dB below peak output power
D. At least 60 dB below peak output power
*
230H-4.2 C 8-6 All of the power can|go to the sidebands
What is one advantage of carrier suppression in a double-sideband
phone transmission?
A. Only half the bandwidth is required for the same information
content
B. Greater modulation percentage is obtainable with lower
distortion
C. More power can be put into the sidebands
D. Simpler equipment can be used to receive a double-sideband
suppressed-carrier signal
*
231H-5.1 A 8-6 SSB
Which one of the telephony emissions popular with amateurs
occupies the narrowest band of frequencies?
A. Single-sideband emission
B. Double-sideband emission
C. Phase-modulated emission
D. Frequency-modulated emission
*
232H-5.2 C 8-6 SSB
Which emission type is produced by a telephony transmitter having
a balanced modulator followed by a 2.5-kHz bandpass filter?
A. PM
B. AM
C. SSB
D. FM
*
233H-7.2 B 8-10 Phase modulation
What emission is produced by a reactance modulator connected
to an RF power amplifier?
A. Multiplex modulation
B. Phase modulation
C. Amplitude modulation
D. Pulse modulation
*
234H-8.1 D 8-6 Aids in demodulation
What purpose does the carrier serve in a double-sideband phone
transmission?
A. The carrier separates the sidebands so they don't cancel in
the receiver
B. The carrier contains the modulation information
C. The carrier maintains symmetry of the sidebands to prevent
distortion
D. The carrier serves as a reference signal for demodulation by
an envelope detector
*
235H-8.2 C 8-3 Carrier
What signal component appears in the center of the frequency
band of a double-sideband phone transmission?
A. The lower sidebands
B. The subcarrier
C. The carrier
D. The pilot tone
*
236H-9.1 C 8-3 Sum and difference, 7250 ± .8 kHz
What sidebands are generated by a double-sideband phone
transmitter with a 7250-kHz carrier when it is modulated
less than 100% by an 800-Hz pure sine wave?
A. 7250.8 kHz and 7251.6 kHz
B. 7250.0 kHz and 7250.8 kHz
C. 7249.2 kHz and 7250.8 kHz
D. 7248.4 kHz and 7249.2 kHz
*
237H-10.1 B 8-12 Bandwith is always two |or more times deviation
How many times over the maximum deviation is the bandwidth
of an FM-phone transmission?
A. 1.5
B. At least 2.0
C. At least 4.0
D. The bandwidth cannot be determined without knowing the
exact carrier and modulating frequencies involved
*
238H-10.2 D 8-12 BW = 2*(D + M) |BW = 2*(5000+3000)|BW = 16,000 Hz
What is the total bandwidth of an FM-phone transmission having
a 5-kHz deviation and a 3-kHz modulating frequency?
A. 3 kHz
B. 5 kHz
C. 8 kHz
D. 16 kHz
*
239H-11.1 A 8-5 In DSB AM, the amplitude of the |envelope varies in proportion to|amplitude of the modulating signal
What happens to the shape of the RF envelope, as viewed on an
oscilloscope, during double-sideband phone transmission?
A. The amplitude of the envelope increases and decreases in
proportion to the modulating signal
B. The amplitude of the envelope remains constant
C. The brightness of the envelope increases and decreases in
proportion to the modulating signal
D. The frequency of the envelope increases and decreases in
proportion to the amplitude of the modulating signal
*
240H-13.1 D 8-4 Overmodulation of a SSB transmitter |causes the signal to become distorted|and occupy more bandwidth
What results when a single-sideband phone transmitter is
overmodulated?
A. The signal becomes louder with no other effects
B. The signal occupies less bandwidth with poor high frequency
response
C. The signal has higher fidelity and improved signal-to-noise
ratio
D. The signal becomes distorted and occupies more bandwidth
*
241H-13.2 B 8-4 Overmodulation of a DSB AM transmitter|causes the signal to become distorted |and occupy more bandwidth
What results when a double-sideband phone transmitter is
overmodulated?
A. The signal becomes louder with no other effects
B. The signal becomes distorted and occupies more bandwidth
C. The signal occupies less bandwidth with poor high frequency
response
D. The transmitter's carrier frequency deviates
*
242H-15.1 B 8-12 Find mult. factor, MF = Fout/Fosc|MF = 146.52 MHz/12.21 MHz, MF = 12|Dosc = 5000/MF = 5000/12 = 416.7 Hz
What is the frequency deviation for a 12.21-MHz
reactance-modulated oscillator in a 5-kHz deviation,
146.52-MHz FM-phone transmitter?
A. 41.67 Hz
B. 416.7 Hz
C. 5 kHz
D. 12 kHz
*
243H-15.2 A 8-7 Mixer
What stage in a transmitter would translate a 5.3-MHz input
signal to 14.3-MHz?
A. A mixer
B. A beat frequency oscillator
C. A frequency multiplier
D. A linear translator stage
*
244H-16.4 A 8-13 An AF shift keyer shifts between two|tones and "at any instant", only one|tone is present in the output signal
How many frequency components are in the signal from an AF
shift keyer at any instant?
A. One
B. Two
C. Three
D. Four
*
245H-16.5 C 8-13 Higher keying speeds |require greater shifts
How is frequency shift related to keying speed in an fsk signal?
A. The frequency shift in hertz must be at least four times the
keying speed in WPM
B. The frequency shift must not exceed 15 HZ per WPM of
keying speed
C. Greater keying speeds require greater frequency shifts
D. Greater keying speeds require smaller frequency shifts
*
246I-1.3 C 9-7 A Yagi antenna has directivity, ie. it|discriminates against interference off|to the side or behind the antenna
Why is a Yagi antenna often used for radio communications on the
20-meter wavelength band?
A. It provides excellent omnidirectional coverage in the horizontal
plane
B. It is smaller, less expensive and easier to erect than a dipole
or vertical antenna
C. It discriminates against interference from other stations off to
the side or behind
D. It provides the highest possible angle of radiation for the HF
bands
*
247I-1.7 D 9-7 A Gamma match is easy to design and|use and it provides an unbalanced |feed point for coaxial cable
What method is best suited to match an unbalanced coaxial
feed line to a Yagi antenna?
A. "T" match
B. Delta match
C. Hairpin match
D. Gamma match
*
248I-1.9 A 9-11 Larger diameter elements
How can the bandwidth of a parasitic beam antenna be
increased?
A. Use larger diameter elements
B. Use closer element spacing
C. Use traps on the elements
D. Use tapered-diameter elements
*
249I-2.1 C 9-11 Four times, which is 6 dB
How much gain over a half-wave dipole can a two-element
cubical quad antenna provide?
A. Approximately 0.6 dB
B. Approximately 2 dB
C. Approximately 6 dB
D. Approximately 12 dB
*
250I-3.1 B 9-9 Lt = 1005/Fmhz, Lt = 1005/21.4|Ls = Lt/4, Ls = 46.96/4|Ls = 11.74
How long is each side of a cubical quad antenna driven
element for 21.4-MHz?
A. 1.17 feet
B. 11.7 feet
C. 47 feet
D. 469 feet
*
251I-3.2 B 9-9 Lt = 1005/Fmhz, Lt = 1005/14.3|Ls = Lt/4, Ls = 70.28/4|Ls = 17.57
How long is each side of a cubical quad antenna driven
element for 14.3-MHz?
A. 1.75 feet
B. 17.6 feet
C. 23.4 feet
D. 70.3 feet
*
252I-3.3 B 9-9 Lt = 1030/Fmhz, Lt = 1030/29.6|Ls = Lt/4, Ls = 34.78/4|Ls = 8.70
How long is each side of a cubical quad antenna reflector
element for 29.6-MHz?
A. 8.23 feet
B. 8.7 feet
C. 9.7 feet
D. 34.8 feet
*
253I-3.4 C 9-10 Lt = 1005/Fmhz, Lt = 1005/28.7|Ls = Lt/3, Ls = 35.02/3|Ls = 11.67
How long is each leg of a symmetrical delta loop antenna
driven element for 28.7-MHz?
A. 8.75 feet
B. 11.32 feet
C. 11.7 feet
D. 35 feet
*
254I-3.5 C 9-10 Lt = 1005/Fmhz, Lt = 1005/24.9|Ls = Lt/3, Ls = 40.36/3|Ls = 13.45
How long is each leg of a symmetrical delta loop antenna
driven element for 24.9-M Hz?
A. 10.09 feet
B. 13.05 feet
C. 13.45 feet
D. 40.36 feet
*
255I-3.6 C 9-10 Lt = 1030/Fmhz, Lt = 1030/14.1|Ls = Lt/3, Ls = 73.05/3|Ls = 24.35
How long is each leg of a symmetrical delta loop antenna
reflector element for 14.1-MHz?
A. 18.26 feet
B. 23.76 feet
C. 24.35 feet
D. 73.05 feet
*