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Calibration Procedure—442 Service

Adjustment Procedure

Connect a 10X probe to the CH 2 input connector.

Connect the  probe tip to a  probe-tip-to-bnc adapter, the
adapter to a 50 Q bnc termination, and the termination to a
50 O  bnc  10X attenuator attached to the  high-amplitude
output  connector  of the  square-wave generator.  Set the
generator to  provide a 5-division,  1  kHz display.

Compensate the probe for the best front corner on

the displayed waveform.

e. ADJUST—R4397, C4397, C4396, R4396 (see Figure

4-9) and C114, R114 (see Figure 4-8), using a low-
capacitance alignment tool, for best front corner of the
waveform.

NOTE

For serial numbers B010409 through B022163, per
form parts g, h, and i and ignore parts f and j.

Set CH 2 VOLTS/DIV to 20 m (IX) and set the

generator for a 5-division display.

For serial numbers below B010409 and above

B022163 perform parts f, g, h, andj and ignore part i.

j. ADJUST—C4213 for the best flat top on the square

wave.

k. Set CH 2 VOLTS/DIV to .2 (IX), and set the

generator amplitude to provide a 5-division display.

ADJUST—C4204 for the best flat top on the dis

played square wave.

m. Disconnect the test equipment from the 442.

ADJUST—(For serial numbers below B010409 and

above B022163) C4155 (see Figure 4-9) for best front
corner of the waveform (use a low-capacitance alignment

tool).

g. Set VERT MODE to CH 2.

Move the 50 Q termination for the square-wave

signal from the Channel 1 input connector to the Channel
2 input connector.

6. High Frequency Compensation

a. Set:

VOLTS/DIV (CH 1 & CH 2)
VERT MODE
SEC/DIV
INTENSITY
LEVEL

2  m  (IX)
CH  1
.5  m

For a visible display
For a triggered display

Connect the square-wave generator fast-rise +

transition output through a 50 D cable, a 10X attenuator,

and a 50 Q termination to the Channel 1 input connector.

Set the generator for a 100 kHz, 5-division display

(set INTENSITY and POSITION controls for a visible
centered display).

Set SEC/DIV to .5

MAGNIFIER to X10 (button in)

and adjust LEVEL and INTENSITY for a visible, stable,

triggered, positive-going square-wave display. Set

Horizontal POSITION control to view the leading edge of

the square wave near the center of the graticule area.

ADJUST—(For serial numbers B010409 through

B022163) C4255 (see Figure 4-9) for best front corner of

the waveform (use a low-capacitance alignment tool).

CHECK—(For serial numbers below B010409 and

above B022163) for asquarefront corneronthe Channel 2
waveform similar to the Channel 1 waveform obtained in
part e.

INTERACTION—If either the Channel 2 waveform

or the  Channel  1  waveform  is not satisfactory,  repeat the
adjustments  and  checks  listed  in  parts  e  through  i  (as
appropriate for the serial  number of the instrument being
adjusted)  for  best  compromise  of  the  waveforms  for

Channel  1  and  Channel  2.  For  example, slightly readjust
C4396,  R4396,  C4397,  R4397,  Cl 14,  and  R114 along with
C4255 (if present) for best Channel 2 display; then change
signal  and  Mode  to  Channel  1  and  check  the  display.
Then,  if  necessary,  readjust  all  listed  components
(including  C4155,  if  present).  Repeat  as  required  to
achieve  best  display front corner for both  Channel  1  and
Channel  2.

I. Disconnect the test equipment from the 442.

4-22

R E V A M A Y 1980