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11.
Plug-In Extension, Type EP54
12. Low-capacitance insulated alignment tools.
13. Resistive shorting strap, approximately 16
inches long. (This may be made from two short
lengths
of insulated stranded w ire, a small
resisto r and two test-lead clips.
w ires to opposite ends of the resistor, attach
the test-lead
clips to the free ends of the
w ires, and tape the resistor. The small r e s is
tor (1/2-watt, 27£2 to lOOfi) serves as a fuse.
Adjustment Procedure
Lay the test oscilloscope on its right side
and remove the left-side and bottom panels.
Insert the Type L Unit and preset the o s c illo
scope and plug-in controls as follows (controls
not mentioned may be in any position):
Oscilloscope:
INTENSITY
HORIZONTAL DISPLAY
MAGNIFIER (5X MAG.)
Main Sweep Controls:
TIME/CM
VARIABLE, TIME/CM
TRIGGER SLOPE
TRIGGERING MODE
(TRIGGERING SOURCE)
S TA B ILITY
TRIGGERING LE V E L
Type L Plug-In Unit:
AC-DC
VOLTS/CM
V AR IAB LE , VOLTS/CM
Turn ON the POWER switch and allow adequate
warm-up
time
for
the instruments.
increasing the intensity, center the trace with
the VE R TIC AL POSITION and the HORIZONTAL
POSITION controls, using the Beam Indicator
neons as a guide. Rotate the INTENSITY con
tro l
clockwise
until the free-running trace
appears on the crt. Adjust the FOCUS, ASTIG-
5-2
(013-019)
MATISM
a sharp trace with adequate intensity. Allow
at least 15 minutes warm-up before making
any adjustment changes.
1 . Set Vertical Position R an ge Control
Solder the
at m id-range, use an insulated screwdriver
to
the
position to the center of the graticule.
2. Check Tubes for G as
the VOLTS/CM switch from .05 to .1 position.
Any shift in trace position should not exceed
2 mm.
input tube (V5832)
gas
checking fo r a purple glow in the center of
the tube.
surface
fully counter
however.
clockwise
gas. Return VOLTS/CM switch to .05 position.
NORMAL (" A" ,
INTERNAL
SWEEP)
3. Check Tubes for Microphonics
OFF
.5 MILLISEC
microphonics (physical vibration of electrodes
CALIBRATED,
fully clockwise
within
-INT. (-)
the oscilloscope trace). If the trace deflection
AUTOmatic
(IN T .)
phonics
(disabled in
section.
GAIN
AUTO.)
(disabled in
deflection
AUTO.)
DC
mine which tube is defective by the following
procedure: Turn off the oscilloscope and remove
.05 (black
the
numbers)
CALIBRATED,
fully clockwise
position at which microphonics were observed;
with
the tip of each tube and watch the crt for
Before
trace
4. Check DC Output Levels
Calibration Procedure - Type L Plug-In
and INTENSITY controls to obtain
With the VE R TIC AL
adjust the Vert.
side of the Type L , bringing the trace
While watching the trace on the crt, switch
If this
lim it is exceeded, a gassy
is
in each of the other tubes by visually
A blue fluorescence on the inside
of the glass does not indicate gas,
Replace any tube found to contain
Rap lightly on the front panel of the Type L
Unit
and watch the trace
a vacuum tube causing deflection of
exceeds 4 mm, a tube with excessive m icro
is
indicated
Switch the
AC and repeat the check. If the trace
is
more than 1 cm, a tube with
excessive microphonics in the X10 am plifier
section is indicated.
If these checks showed microphonics, deter
Type L Unit; install an EP 54 Plug-In
Extension and re-in sert the L Unit; turn the
scope on again; Set the AC-DC switch to the
a long flexible adjustment tool, stroke
deflection.
Replace
excessive microphonics.
With the trace centered, check thedc voltages
POSITION
knob set
Pos. Range control on
indicated.
Check for
for ringing type
in the main amplifier
AC-DC
switch to X10
any tubes with
AA
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