2. Assume that you observe a digital waveform on an oscilloscope. The fact
that you find no change in waveshape of the received signal as compared with
the transmitted signal indicates that the
a. envelope delay is maximum.
b. carrier frequencies are identical.
c. limiters are clipping the signal peaks.
d. harmonic-frequency relationship is maintained.
3. When the phase shift of a circuit is directly proportional to a change in
frequency, the circuit exhibits the characteristic of
a. constant delay.
b. zero phase shift.
c. nonlinear rise of delay time.
d. linear relationship between amplitude and frequency.
4. Assume that a technician observes that a received digital pulse train is
identical with the original waveform. He can deduce from this waveform that
the
a. phase delay is proportional to frequency.
b. pulse delay time is proportional to frequency.
c. circuit has nonlinearity of delay with respect to frequency change.
d. higher order harmonics making up the digital pulses are all shifted the
same amount.
5. In the simple amplitude-frequency equalizer shown in figure 4-2,
midfrequency equalization is accomplished by adjustment of resistors R1 and R2.
Midfrequency equalization results from the fact that these resistors will
a. correct for amplifier response.
b. broaden the response curves by varying Q.
c. change the resonant frequencies of the tuned circuits.
d. modify the loss characteristic of the telephone line proper.
6. Assume that you are equalizing a long telephone line.
If you follow
recommended procedure you will measure level at the
a. amplifier input.
c. amplifier output.
b. equalizer input.
d. equalizer output.
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