Hitachi V-355, Operation Manual

Page: 13 / 54

10
GND At this setting the input to the vertical axis ampli­
fier is grounded.
DC At this setting the input signal is directly con­
nected to the vertical axis amplifier and displayed
unchanged, including the DC component.
@@
VOLTS/DIV select switches
A step attenuator which selects vertical deflection fac­
tor. Set it to an easily observable range corresponding to
the amplitude of the input signal.
Multiply the reading by IO when the 10: 1 probe is used
in combination with the instrument.
@) @
VAR
PULL xS GAIN
controls
Fine tuning device used to vary the vertical deflection
sensitivity continuously. Attenuation of less than 1 /2.5
is obtained when this device is rotated in the reverse
direction of the arrow to the
full.
This control is used when comparing waveforms or when
measuring the rise time of a square wave in 2-channel
observation. Normally this control is left rotated in the
direction of the arrow to the
full.
When the knob is at
PULL position (pulled up state) the gain of the vertical
axis is magnified 5 times and the maximum sensitivity
becomes 1 m V /DIV.
@ @
UNCAL lamp
Light when VAR is out of CAL detent position.
@
POSITION controls
This knob is used to adjust the position of the vertical
axis.
The display rises with a clockwise rotation of this knob
and falls with a counterclockwise rotation.
POSITION
control
PULL INVERT
The same as CHI, but when the knob is at PULL posi­
tion (pulled up state), the polarity of the input signal
applied to CH2 will be inverted.
This control is conveniently used in the comparison of
two waveforms having different polarity or in the obser­
vation of the waveform of the difference between signals
of CHI and CH2 using ADD facility.
@
MODE
select switch
This switch is used to select the operation mode of the
vertical deflection system.
CH 1 Only the signal that has been applied to CH 1
appears on the screen.
CH2 Only the signal that has been applied to CH2 ap­
pears on the screen.