Maintenance
—
Type 175
are numbered
differently).
As
with
the
Type
575,
the
volt
age
drop
across
the
current-sampling
resistor
(R244
in
the
Type
175,
R246 in
the Type 575
should
increase
from
zero
by
0.5
volt
steps
regardless
of the
position
of
the
STEP
SELECTOR
switch.
The
maximum
current
which
must
be
supplied
by
the
Step
Amplifier
power
supplies
in
the
Type
175
is
12
amperes as compared
to
2.4
amperes
in
the
Type
575.
Note
also
that
the
Type
175
Step Amplifier
has
a
VOLTS/STEP
ADJ.
adjustment at
its
input,
the
setting
of
which
can
affect
the
amplitude
of
the
signal
throughout
the
circuit.
Throughout
the procedures,
the
Type
175
and
Type
575
should
be
connected
together
for
combined
operation,
as
described
under
Operating
Instructions,
and
turned
on,
un
less
otherwise noted.
For
a
complete
checkout of
all
switches,
the
procedures
should
be
performed
in
the
order
presented.
If
you
merely
wish
to
check
the
operation
of
one
of
the
switches,
you
may
check
it
separately
as
long
as
you
realize
that,
in
these
procedures,
an
off-value
resistor
in
the
HORIZONTAL
DISPLAY
switch
can
make
any
of
the
other
switches
(except
the
SERIES
RESISTANCES
switch)
ap
pear
faulty.
Troubleshooting
the
Collector Sweep Circuit
The
cause
of
insufficient or
no
output
voltage
from
the
Collector
Sweep
circuit
can
be
isolated
by
continuity
checks
through
the
circuit.
Verification
of
sufficient
output
can
be
made
by
measurements
described
later
in
the
procedure
for
checking
the resistors
of
the
VERTICAL
DISPLAY
switch.
Checking
Switch
Resistance
The
following
procedures tell
you
how
to
check
the
re
sistors
in
the
HORIZONTAL
DISPLAY, STEP
SELECTOR,
VERTICAL
DISPLAY,
and
SERIES
RESISTANCE
switches
of
the
Type
175 for proper
values.
Since
the
Type
575
and
the
Type
175
are
essentially
self-checking, this
can
be
done
by
measurements
observed
on
the
screen
of
the
Type 575.
In
each
measurement,
the
faulty
resistor
can be
determined
by
comparing
the
position
of
the
switch
in
which
a
faulty
indication
is
obtained
with
the
appropriate
schematic
dia
gram.
To
perform
the
measurements,
you
will
need
four
precision (1
%)
resistors
of
the
following
values
and
ratings.-
100
ohms,
1
watt;
2 ohms,
50
watts; 0.05
ohms,
1000
watts;
and
10
ohms,
500 watts.
These
resistors
will
be
referred
to
in
the
procedure
by
their
resistance
values
only.
HORIZONTAL
DISPLAY
and
STEP
SELECTOR
Switches.
To
check
the
resistors
associated with
the
HORIZONTAL
DISPLAY
and
STEP
SELECTOR switches,
proceed
as
follows:
1.
Connect
the
resistor designated
in
the
first
column
of
Table
1
between
the
E
and
B
binding posts
to
the
TRANSI
STOR
A
side
of
the
Transistor
Test
Panel
of
the
Type
175.
2.
Set
the
STEP
SELECTOR
and HORIZONTAL DISPLAY
switches
to
the
positions
shown in
the
second
and
third
columns
of
the
table.
3.
Set
the Transistor
Selector
switch
to TRANSISTOR
A
and
the
STEPS/FAMILY
control
(on
the
Type
575)
fully
clock
wise.
The
display
on
the
Type
575
screen
should
contain
the
number
of
dots per
division
shown
in
the
fourth
column
of
the
table.
4.
Continue
in
like
manner
down
the
table,
inserting
the
proper
resistor
and
setting
the
controls
as
designated,
and
check for
the
proper
number
fo
dots
per
division
in
the
dis
play
for
each
measurement.
(Remove
the
resistor
for
the
last
five
measurements on the
table.)
If
an
incorrect
display
first occurs
in
the
second,
fourth,
sixth,
of
eighth
measurement
of
the
table,
the
trouble
is
in
TABLE
I
Resistor
(between E
and
B
posts)
STEP
SELECTOR
switch
HORIZONTAL
DISPLAY
switch
(BASE
V
b„)
Dots
per
division
100
<2
1
MA/STEP
.1................
1
100
22
1
MA/STEP
.2
2
100
22
2
MA/STEP
.2
1
100
22
2
MA/STEP
.5
5
dots
per 2 divisions
100
22
5
MA/STEP
.5
1
100
22
5
MA/STEP
1
2
100
22
10
MA/STEP
1
1
100
22
10
MA/STEP
2
2
100
o
20 MA/STEP
2
1
2
22
50
MA/STEP
.1
1
2
<2
100
MA/STEP
.2
1
2
22
200
MA/STEP
.5
5
dots
per 4 divisions
2
22
500
MA/STEP
1
1
2
22
1000
MA/STEP
1
1
dot
per
2
divisions
open
.02
VOLTS/STEP
.1
'
5
open
.05
VOLTS/STEP
.1
2
open
.1
VOLTS/STEP
.1
1
open
.2
VOLTS/STEP
.2
1
open
.5
VOLTS/STEP
.5
1
6-6
®2
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 ...
Page 26: ...NOTES ...
Page 48: ...NOTES ...
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 ...
Page 115: ... 300 ...
Page 119: ...Type 175 Tent S N 570 PARTS LIST CORRECTION Change to Q233 151 0137 00 2N21U8 MIO 298 1165 ...
