Tektronix TYPE L Instruction Manual page 22

o r two ranges, check the compensation of the
input attenuators. If the distortion occurs on
all ranges, firs t check the compensation of
the probe used. In signal tracing for high-
frequency distortion, consider the loading effect
o f the probe.
Distortion can be divided into two categories:
(1) low-frequency distortion, illustrated in Fig.
4-2 and (2) high-frequency distortion, illustrated
in Fig. 4-3.
(1 ) Any low-frequency distortion in the wave­
form w ill be produced by the X10 amplifier.
m
Fig. 4-2. (a) Low-frequency distortion caused by attenuation in X 10-am plifier, (b) Waveform distortion
from low-frequency overcompensation in X10-amplifier.
duced by excessive
R efer to the Circuit
explanation of this circuit.
Fig. 4-3. (a) Waveform showing insufficient high-frequency peaking,
high-frequency peaking.
4-6
a
low-frequency " b o o st".
Description fo r an
Maintenance - Type L Plug-In
(The main am plifier is dc-coupled, and its
response is therefore flat down to dc.)
Low-frequency attenuation w ill produce the
type of distortion illustrated in Fig. 4-2(a). This
type of distortion can be caused by cathode
and screen-bypass capacitors, and by coupling
capacitors. B efore attempting any component
replacement, however, be sure to check the
adjustment of the Lpw
(R6182), as explained
Procedure.
Over-compensation
illustrated in Fig. 4-2(b). This condition is pro-
(2 ) Insufficient high-frequency peaking,which
lim its the risetim e and consequently the band­
width, w ill produce the rounded-corner type
(b) Spiking caused by excessive
Freq. Adj. control
in the Calibration
of low frequencies is
b
AA