Heathkit IO-4205 - Page 89

from Y1 to Y2 and the Y1-Y2 EXT-LINE switch
from Y1 to Y2.
( )
Now repeat the trigger zero adjustment for the
Y2 channel.
LOW-CAPACITY PROBE
NOTE: If you do not have a low capacity probe, disre-
gard
the following steps and proceed to "Final As-
sembly."
( ) Set
the Y1-Y2-CHOP-ALT switch to Y1 and the
TRIGGERING switches to Y1, AC, +, and
AUTO.
Set the TIME/CM switch to 200 ~J-S.
Set the Y1 VOLTS/CM switch to 0.05 and the
VARIABLE control fully clockwise.
( )
Connect a low-capacity probe to the Y1 INPUT
connector.
( )
Connect the probe to a 1 kHz square wave sig-
nal.
. ( )
Adjust the output of the generator to produce a
display that is 4 em high.
( )
Adjust the compensation capacitor on the probe
for a· proper square wave with no overshoot as
shown in Pictorial 6-7.
Set
the VOLTS/CM switch to 0.5.
Readjust
the generator output for a 4 em dis-
play .
( )
Adjust Y1 trimmer capacitor #1 for a proper
square wave. If you cannot make this adjust-
ment, readjust the probe capacitor and
capacitor #1 until the correct waveform is dis-
played.
Page 87
( )
Set
the VOLTS/CM to 0.05 and readjust the
generator output for a 4 em display again.
( )
Adjust trimmer capacitor #2 for a proper square
wave.
NOTE:
If necessary, repeat the previous steps until a
proper square wave is displayed.
( ) Repeat
the previous steps under "Low-Capacity
Probe" for the Y2 channel. However, whenever
Y1 is called for, insert Y2. If may be possible to
adjust channel Y2 without changing the probe
compensation capacitor. If this happens, then
you will be able to use the same probe on either
channel and will not need to make any adjust-
ments when using the probe.
( ) Disconnect
the Low-Capacity Probe.
PHASE ADJUSTMENT
( ) Change the Y1-Y2-CHOP-ALT switch to the
CHOP position.
( ) Change
the TIME/CM switch to the 2 IJ-S posi-
tion.
( ) Set
the four TRIGGERING switches to the EXT,
DC, +, and AUTO positions.
, ( )
Adjust the SWEEP V AR Y1 POS and Y2 , POS
controls for a
pattern similar to that shown in
Pictorial 6-10.
( )
Adjust the PHASE ADJ control (see Pictorial
6-5) so
there is no vertical trace information at
the beginning, between, or after any of the hori-
zontal trace lines.
( )
Turn off the Oscilloscope POWER switch and
unplug the line cord .
This completes the Calibration of the Oscilloscope.
Proceed to
the " Final Assembly" section of the Man-
ual.