Tektronix T912 - Amplifier

operating
Instructions—
T912
See
Operating
Voltage on page
2-1
for 120
V/240 V
and HI/LO
switch information.
(1932) 1981-17A
Fig.
2-4.
Bottoin of
cabinet.
CH 2
DC BAL—
Screwdriver
adjustment. When
properly adjusted,
prevents trace
shift when
switching
between
adjacent
positions of the CH 2
VOLTS/DIV
switch.
B.
VERTICAL
AMPLIFIER
Input
Coupling-Selects
the
method
of
coupling
the
input
signal
to
the
vertical input
signal
amplifier.
AC:
Signals
are
coupled
capacitively.
Any dc
signal
component
is
blocked. Low
frequencies
are
attenuated (3
dB
down
at
about
1 Hz
using
a
10X
probe).
Ac
coupling
causes
tilting
of
square
waves
below
about
1
kHz.
Front Panel (Fig.
2-5)
VOLTS/DIV—
Selects the
vertical
deflection factor
in a
1-2-5
sequence (VAR
control must be in
detent
position to
obtain the
indicated deflection
factors).
Read
the
correct
deflection
factor
for
a
IX probe
from the
IX
position and a
10X probe from the
10X
position.
VAR—Provides
continuously
variable
uncalibrated
deflection
factors
between
the
calibrated steps
of
the
VOLTS/DIV switches.
Extends the
maximum
deflection factor
to 25
V/div in
the
10 V position.
Detent
position provides
calibrated
VOLTS/DIV
deflection factors.
GND:
Grounds
the
input of
the
vertical
amplifier
to provide
a ground
reference
display.
Connects
the
input
signal
to
ground
through
the
input
coupling
capacitor
and a
1 MO
resistor
to
allow
the input
coupling
capacitor
to
be
precharged
by the
input
signal.
DC:
All
components
of the
input
signal
are
passed
to the
vertical
amplifier.
Channel 1
or
Y Input—
Connector for
applying an
external
signal to
the vertical
deflection
system.
Provides
the Y
input in the
X-Y mode
when
CH 1
vertical
mode button
is
in.
2-4
REV B, DEC
1978