Fig. 3 4 indicates high-frequency boost in an amplifier
accompanied by a lightly damped "shock" transient. In this
case, the sudden transition in the square wave potential
from a sharply rising, relatively high frequency voltage, to a
level value of low frequency voltage, supplies the energy for
oscillation in the resonant network. If this network in the
amplifier is reasonably heavily damped, then a single cycle
transient oscillation may be produced as indicated in Fig. 35.
Fig. 3 6 summarizes the preceding explanations and
serves as a handy reference.
Fig. 35. Effect of high-frequency boost and
good
damping
Frequency distortion, (amplitude
reduction of low-frequency com-
ponent). No phase shift.
B. Low - frequency boost (accentu-
ated fundamental).
C. High-frequency loss—No phase
shift.
D. Low-frequency phase shift.
E. Low - frequency loss and phase
shift.
F. High-frequency loss and low-fre-
quency phase shift.
G. High - frequency loss and phase
shift.
H. Damped oscillation.
I. Low-frequency phase shift (trace
thickend by hum-voltage).
Fig.
36. Summary of waveform analysis for square wave testing of amplifiers
25
