Maintenance
— Type
175
the
corresponding
position
of
the
HORIZONTAL
DISPLAY
switch.
An
incorrect
display
in
any
of
the
other measure
ments
indicates that
the
trouble
is
in
the
corresponding
posi
tion
of the
STEP
SELECTOR
switch.
A
small
consistent
error
at
all
positions
of
both
switches
indicates a
need
for
adjust
ment of the
internal
VOLTS/STEP
ADJ.
adjustment
[see
Calibration).
If
the
dots
are consistently
farther apart
in
the
VOLTS/STEP
positions
of
the
STEP
SELECTOR
switch
than
in
the
MA/STEP
positions,
this
indicates
that
R246
has
increased
in
value
or
the wiring
resistance of the
circuit
has
increased.
Conversely,
if the
dots
are
consistently
closer
together
in
the VOLTS/STEP position
of
the
STEP
SELECTOR
switch
than
in
the
MA/STEP
positions,
this
indicates
that
R246
has
de
creased
in
value
or
has
become
shorted.
HORIZONTAL
DISPLAY
Switch
(COLLECTOR
V
ce
Posi
tions)
After
you
have
verified
the
accuracy
of
all
the
BASE
V
be
positions
of
the
HORIZONTAL DISPLAY switch,
pro
ceed as
follows
to
check
the resistors
associated
with
the
COLLECTOR
V..„
positions
of
the
switch:
1. Set
the
Transistor
Selector
switch
to
TRANSISTOR
A,
the
PEAK
VOLTS
RANGE
switch
to
0-20,
and the
PERCENT
OF
PEAK
VOLTS
RANGE
control
to
0.
2. Set
the
HORIZONTAL
DISPLAY
switch
to
2
COLLECTOR
V
ce.
3.
Rotate
the
PERCENT
OF
PEAK
VOLTS
RANGE
con
trol
clockwise
until
you
obtain
exactly
10
divisions
of
hori
zontal
deflection
on
the
screen.
4.
Set
the
HORIZONTAL
DISPLAY
switch
to 5 COLLECTOR
V
ce
.
There
should
be
four
divisions
(:J~2%)
of
horizontal
deflection
on
the
screen.
5. Return
the
PERCENT
OF
PEAK
VOLTS
RANGE
control
to
0.
6.
Set
the
PEAK
VOLTS
RANGE switch to
0-100
and
the
PERCENT
OF
PEAKS
VOLTS
RANGE
control
for
exactly
10
divisions
of
horizontal
deflection.
7. Set
the
HORIZONTAL
DISPLAY
switch
to
10
COL
LECTOR
V
cs.
There should
be
five
divisions
(zr2%)
of
hori
zontal
deflection
on
the
screen.
(The
remaining
COLLECTOR
V
ce
positions
of
the
HORI
ZONTAL
DISPLAY switch
use
the same resistors
as the
BASE
V
c
„
positions
which
were
checked previously.)
VERTICAL
DISPLAY Switch.
In
checking
the
resistance
in
the
VERTICAL
DISPLAY
switch,
the
output
of
the Coltector
Sweep
circuit
is
applied
across
an
externally connected
resistor
at each
setting
of
the
VERTICAL
DISPLAY
switch.
The
voltage
across
the
resistor
is
displayed as
horizontal
deflection
and
the
current
through
the
resistor
is
displayed
as
vertical
deflection. The
slope
of
the
line
displayed,
as
the
Collector
Sweep
output
sweeps
between
zero
and a
selected
maximum
voltage,
should
indicate
the
value
of
the
external
resistance.
Any
deviation
from
the
proper slope
indicates
an
off-value
current
sampling
resistor
(assuming
that
the
resistances
in
the
HORIZONTAL
DISPLAY
switch
as
measured
previously
are all
correct).
To
check
the
resistances
in
the
VERTICAL
DISPLAY
switch,
proceed
as
follows:
1. Set
the
PERCENT
OF
PEAK
VOLTS
RANGE
control
to
0.
2. Set
the
COLLECTOR SWEEP POLARITY
switch
on
the
Type
175
to +.
3.
Connect
the
resistor
designated
in
Column
A
of
Table
II between
the
large
C
and
E
terminals
on
the
TRANSISTOR
A
side
of
the
transistor
Test
Panel
of
the
Type
175
using
the
high-current
test
cables.
4.
Connect
test
leads
from
the
ends
of
the
resistor
to
the
V,,,
EXT.
INPUT
binding posts
on
the
same
side
of
the
Tran
sistor
Test
Panel.
5.
Set the
Transistor
Selector
switch
to
TRANSISTOR
A.
6.
Set
the
PEAK
VOLTS
RANGE,
VERTICAL
DISPLAY,
and
HORIZONTAL
DISPLAY
switches
on
the
Type
175 to
the
positions
designated
in
columns
B,
C,
and
D
of
Table II.
7.
Adjust
the
POSITION
controls
on
the
Type
575
to
posi
tion
the
spot
to
the
lower
left
corner
of
the
graticule.
8.
Rotate
the
PERCENT
OF
PEAK
VOLTS
RANGE
control
clockwise
until
you
obtain
the
horizontal
deflection
specified
in
column
E
of
the table.
The
slope
of
the
line
(A
vertical
deflection
divided
by
A
horizontal
deflection)
should
be
within
2%
of
that
specified
in
column
F.
NOTE
In the
first measurement, you
may
not
be
able
to
obtain
the full
10
divisions
of
horizontal
deflec
tion
before
the
circuit
breaker
actuates.
However,
if
the
slope of the
displayed
lines
is
correct,
the
measurement
may
be considered to be
within
tolerance.
If
the
circuit
breaker
does
actuate,
re
turn
the
PERCENT
OF
PEAK
VOLTS
RANGE
control
to
0
and
wait
one
minute
for the
heating
element
in
the
breaker
to
cool
before
resetting
it.
9. Return
the
PERCENT
OF
PEAK
VOLTS
RANGE
control
to 0
after
each
measurement.
10.
Continue
in
like
manner
down
the table, inserting
the
proper
resistor
and
setting
the
controls
as
designated,
and
check
for
adequate
deflection
and
proper
slope
on
the
Type
575
screen.
If
any
of
the
slopes
are
not
correct,
or
if
ad
equate
horizontal
deflection
cannot be
obtained,
make
a
note
of
it
(whether
the
slope
is greater
or
less
than
specified)
and
go
on
to the
next measurement.
If
the
slope
is
correct
for
the
first
few
measurements
in
Table
II,
but
is incorrect for
the
remaining
measurements,
this
indicates
that
one
of
the
current-sampling
resistors
has
changed
in
value.
It
will
generally
be
the
resistor
associated
with
the
VERTICAL
DISPLAY
switch
position
at
which
the
in
correct
slope first
occurred
as
you
progressed
down
the
table.
If
the
slope
is
greater
than
specified,
the
resistor
has
increased
in
value;
if
the
slope
is
less
than
specified, the
resistor
has
decreased
in
value.
Insufficient
horizontal
deflection
in
the fifth and/or
seventh
measurements
of
the
table
(1
and
2
positions
of
the
VERTI
CAL
DISPLAY
switch,
respectively)
indicates that
the
internal
resistance
of
the
Collector
Sweep
circuit
itself has
increased
beyond
its
proper
value.
In
this
case,
check
T702
and
the
associated
rectifier
diodes as
described
in
the
paragraph
on
Troubleshooting
the
Collector
Sweep Circuit.
®i
Summary of Contents for 175
Page 4: ...VWTICM OINltAlO TRANSISTOR CUM TRACfR UB l COUlClO r hokizoniai VCKIJ O lUnK Hix M Type 575 z ...
Page 6: ...NOTES ...
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Page 54: ...Recalibration Type 575 C706 Fig 5 3 Left Side View 5 6 ...
Page 56: ...NOTES ...
Page 100: ...INPUT AMPLIF1E ...
Page 104: ...TYPE 575 TRANSISTOR CURVE TRACER ...
Page 108: ...OSCILLATOR 4OOV UNREG TYPE 575 TRAN5I5TOR CURVE TRACER AB ...
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Page 119: ...Type 175 Tent S N 570 PARTS LIST CORRECTION Change to Q233 151 0137 00 2N21U8 MIO 298 1165 ...