(2) Invert the signal applied to channel 2 by pulling the invert switch
located with vertical channel 2 controls.
(3) When the undesired components of both signals, opposite in polarity,
are added algebraically, adjust the channel 2 volts-per-division switch and
variable control to reduce the undesired signal.
The trigger control is a dial concentric with the mode switch (fig 2-8a).
The trigger control selects the source of internal triggering signal from the
vertical system. When the trigger control is set to normal, the sweep circuits are
triggered from the displayed channel(s). Also, the channel 1 signal is available
at channel 1 output connector, which is located on the side panel (fig 2-8b). If
the trigger control is set to the channel 1 only position, the sweep circuits are
triggered only from a signal on channel 1. No signal is available at the channel 1
Since the vertical controls of channel 1 (fig 2-8a) are duplicated in channel
2, we will cover only the vertical controls of channel 1.
Keep in mind that
channel 2 controls perform the same function.
a. Locate the channel 1 volts-per-division switch on the left side of the
front panel under the trace finder button.
When you select a position on the
volts/division control, you select a specific combination of frequency-compensated
attenuator networks through which the applied signal must pass.
To be specific, the variable control provides a
continuously variable deflection factor to at least 2.5 times the setting of the
Always turn the variable control clockwise to the
calibrated position when you adjust the vertical gain of that channel.
c. To check the vertical gain of the channel, the volts/division switch is
set to 20 mV, and a 0.1-volt signal from the calibrator is connected to the
channel's input jack.
If the vertical deflection does not measure exactly 5
divisions, turn the gain adjustment to obtain exactly 5 divisions of deflection.
The gain should be set with the volts/division switch set to 20 mV.
The step attenuator balance control (fig 2-8a).
You should make the gain
adjustment before making the step attenuator check.
a. To check the step attenuator balance, set the AC-GND-DC switch to GND, and
set the A sweep mode switch to automatic trigger to produce a free-running sweep.
b. When a vertical shift in the trace occurs as you change the volts/division
switch from 20 mV to 4 mV, an adjustment is required.
c. To make the step attenuator balance adjustment, position the trace to the
graticule centerline when the volts/division switch is set to 20 mV. Then rotate
the volts/division switch to 5 mV and adjust the step attenuator