Tektronix 2246 1Y, Service Manual

Page: 286 / 433

VOLTAGE/WAVEFORM SETUP CONDITIONS
WAVEFORMS
Test waveforms are shown on a page just before the
schematic diagram to which they apply. Normal con­
trol settings for the test oscilloscope are given in the
readouts shown in each waveform illustration.
Unless otherwise indicated near the waveform,
setup conditions for the oscilloscope under test are
as follows:
1. Set up the 2246 1Y or 2246 Mod A front-panel
controls as follows:
VERTICAL MODE
CH 1 COUPLING
CH 1 VOLTS/DIV
VERTICAL POSITION Controls
SCOPE BW
HORIZONTAL MODE
A/B SELECT
SEC/DIV
Trigger LEVEL
HOLDOFF
SLOPE
Trigger MODE
Trigger SOURCE
Trigger COUPLING
MEASUREMENTS
MENU Displays
A INTEN
READOUT
FOCUS
SCALE ILLUM
CH 1 (other
channels off)
DC
0.1 V
12 o’clock
On
A
A
0.1 ms
12 o’clock
min (CCW)
_ r
AUTO LEVEL
VERT
DC
OFF
OFF
10 o ’clock
12 o ’clock
for well de­
fined display
fully CCW
supply, first connect the power cord of the
2246 1Y or 2246 Mod A under test through an
isolation transformer, then connect probe
ground wire to ground “ P” (rear side of R2256).
See Figure 9-12 to locate ground “ P” .
WARNING
To
a v o id e le c tric s h o c k a n d in s tru m e n t
d a m a g e , a lw a y s c o n n e c t th e p o w e r c o rd o f
th e in s tru m e n t u n d e r te s t th ro u g h a n is o la tio n
tra n s fo rm e r w h e n v ie w in g w a v e fo rm s o r
m e a s u rin g v o lta g e s in th e lo w - v o lta g e p o w e r
s u p p ly .
DC VOLTAGES
Dc voltages shown the schematic diagrams are typi­
cal of a normally operating instrument. Voltages are
referenced to chassis ground, except in the isolated
portion of the Low Voltage Power Supply where they
are referenced to ground “ P” (at R2256 as shown
in Figure 9 -1 2). Make sure that the DMM leads are
floating (isolated from chassis ground) when
measuring voltages in this section.
TEST EQUIPMENT
The following test equipment is recommended for
obtaining waveforms and voltages from the 2246 1Y
and 2246 Mod A Oscilloscopes. Other similar equip­
ment types can also be used.
2. Connect the front panel PROBE ADJUST output
to the channel 1 input connector.
3. For all waveforms, except those obtained from
the Low-Voltage Power Supply, connect the test
oscilloscope probe ground wire to the chassis.
When obtaining waveforms from the power
1. Test Oscilloscope with 10X probe (s) —
TEKTRONIX 2246 1Y or 2246 Mod A.
2. Digital Voltmeter-TEKTRONIX DM 501 A.
3. Power-Line Isolation Transformer—Tektronix Part
No. 006-5953-00.