E7C Impedance-matching networks: Pi, L,
Pi-L; filter circuits:
constant K, M-derived, band-stop, notch, crystal lattice, pi-section,
T-section, L-section, Butterworth, Chebyshev, elliptical; filter
applications (audio, IF, digital signal processing {DSP})
E7C01
(D)
How are
the capacitors and inductors of a low-pass filter pi-network arranged between
the network's input and output?
A. Two inductors are in series between the
input and output and a capacitor is connected between the two inductors and
ground
B. Two capacitors are in series between the
input and output and an inductor is connected between the two capacitors and
ground
C. An inductor is in parallel with the input,
another inductor is in parallel with the output, and a capacitor is in series
between the two
D. A capacitor is in
parallel with the input, another capacitor is in parallel with the output, and
an inductor is in series between the two
E7C02
(B)
What is
an L-network?
A. A network consisting entirely of four
inductors
B. A network consisting of
an inductor and a capacitor
C. A network used to generate a leading phase
angle
D. A network used to generate a lagging phase
angle
E7C03
(C)
A
T-network with series capacitors and a parallel (shunt) inductor has which of
the following properties?
A. It transforms impedances and is a low-pass
filter
B. It transforms reactances and is a low-pass
filter
C. It transforms impedances
and is a high-pass filter
D. It transforms reactances and is a high-pass
filter
E7C04
(A)
What
advantage does a pi-L-network have over a pi-network for impedance matching
between the final amplifier of a vacuum-tube type transmitter and a multiband
antenna?
A. Greater harmonic
suppression
B. Higher efficiency
C. Lower losses
D. Greater transformation range
E7C05
(C)
How
does a network transform one impedance to another?
A. It introduces negative resistance to cancel
the resistive part of an impedance
B. It introduces transconductance to cancel the
reactive part of an impedance
C. It cancels the reactive
part of an impedance and changes the resistive part
D. Network resistances substitute for load
resistances
E7C06
(B)
What
value capacitor would be required to tune a 20-microhenry inductor to resonate
in the 80-meter band?
A. 150 picofarads
B. 100 picofarads
C. 200 picofarads
D. 100 microfarads
E7C07
(D)
Which
filter type is described as having ripple in the passband and a sharp cutoff?
A. A Butterworth filter
B. An active LC filter
C. A passive op-amp filter
D. A Chebyshev filter
E7C08
(C)
What
are the distinguishing features of an elliptical filter?
A. Gradual passband rolloff with minimal
stop-band ripple
B. Extremely flat response over its passband,
with gradually rounded stop-band corners
C. Extremely sharp cutoff,
with one or more infinitely deep notches in the stop band
D. Gradual passband rolloff with extreme
stop-band ripple
E7C09
(B)
What
kind of audio filter would you use to attenuate an interfering carrier signal
while receiving an SSB transmission?
A. A band-pass filter
B. A notch filter
C. A pi-network filter
D. An all-pass filter
E7C10
(D)
What
characteristic do typical SSB receiver IF filters lack that is important to
digital communications?
A. Steep amplitude-response skirts
B. Passband ripple
C. High input impedance
D. Linear phase response
E7C11
(A)
What
kind of digital signal processing audio filter might be used to remove unwanted
noise from a received SSB signal?
A. An adaptive filter
B. A notch filter
C. A Hilbert-transform filter
D. A phase-inverting filter
E7C12
(C)
What
kind of digital signal processing filter might be used in generating an SSB
signal?
A. An adaptive filter
B. A notch filter
C. A Hilbert-transform
filter
D. An elliptical filter
E7C13
(B)
Which
type of filter would be the best to use in a 2-meter repeater duplexer?
A. A crystal filter
B. A cavity filter
C. A DSP filter
D. An L-C filter