The difference between the IF and the BFO frequencies is called
Ainformation signal
Bbeat frequency
Ccarrier signal
Dheterodyned signal
#263
A system that provides narrowband voice communications for land mobile services with nearly the quality acheived with FM systems and do it using less than one-third the bandwidth
ASSBFC
BDSBFC
CACSSB
DSSBAC
#264
It is a multipexing method that uses double-sideband suppressed-carrier transmission to combine two information sources into a single composite waveform
AQM
BWDM
CTDM
DFDM
#265
An SSB transmitter has an average output power equal to _______ of that PEP rating.
A1/4 to 1/3
B1/4 to 1/2
C1/5 to 1/2
D1/3 to 2/3
#266
Noise interferes mainly with modulating signals that are
ASinusoidal
BNon sinusoidal
CLow frequencies
DHigh frequencies
#267
Which of the ff is true about the NE566 IC
AIt is a VCO
BIts output is sinusoidal
CIt is an FM demodulator
DIt uses LC-tuned circuits
#268
Over a narrow range of frequencies, the PLL acts like a
ALow-pass filter
BBandpass filter
CTunable oscillator
DFrequency modulator
#269
The output of a PLL frequency demodulator is taken from the
ALow-pass filter
BVCO
CPhase detector
DNone of them
#270
It is also known as upward or downward modulation
Acarrier shift
Bamplitude variations
Cfrequency shift
Dphase shift
#271
Demodulating quadrature AM signal requires a carrier recovery circuit to reproduce the original carrier frequency and phase and two balanced modulators to actually demodulate the signals. This is called
Aasynchronous detection
Bquadrature demodulation
Csynchronous detection
Dquadrature detection
#272
Quadrature amplitude modulation is also known as _________
Aphase division multiplexing
Bphase division modulation
Cphase amplitude multiplexing
Dphase angle modulation
#273
For public safety transmitters, what is their maximum deviation value?
A25 kHz
B75 kHz
C5 kHz
D50 kHz
#274
What signal sensitivity do most good receivers have?
A2 microvolt
B1 microvolt
C3 microvolt
D5 microvolt
#275
How does the adder differ from the mixer?
Aadder must be linear to prevent heterodyning
Badder has more than two inputs
Cmixers are linear devices
Dall of these
#276
In stereo FM, of the total modulation, what percent in main channel?
A10 %
B25 %
C30 %
D45 %
#277
In stereo FM, of the total modulation, what percent in pilot subcarrier?
A10 %
B25 %
C30 %
D45 %
#278
Where is the de-emphasis added in stereo FM receiver?
Amatrix
Bbuffer
Cpilot carrier
Ddoubler
#279
A circuit used to select the desired output from a mixer
ATransformer
BResonant circuit
CFilter
DPhase-shift circuit
#280
What is usually used to demodulate SSB or CW signal?