Maintenance—Type
3B5
tion
is
very
helpful
in
locating
troubles.
See the
Circuit
Description
section
for
complete
information.
Troubleshooting
Aids
Diagrams.
Circuit
diagrams
are
given
on foldout
pages
in
Section
9.
The
component
number
and
electrical
value
of
each
component
in
this
instrument
are
shown
on
the
diagrams.
Each
main circuit is
assigned
a
series
of
com
ponent
numbers. Table
4-1
lists
the main
circuits in
the
Type
3B5
and
the
series
of
component
numbers
assigned
to
each.
Important
voltages
and
waveforms are also shown on
the
diagrams.
The
portions of
the
circuit mounted
on
circuit
boards
or cards are
enclosed
with
a blue line.
Switch
Wafer
Identification.
Switch
wafers
shown
on
the
diagrams
are
coded
to
indicate
the
position
of
the
wafer
in
the
complete
switch
assembly.
The
numbered
portion
of
the
code
refers
to
the
wafer number
counting from
the
front,
or
mounting
end
of
the
switch,
toward
the
rear.
The
letters
F
and
R indicate
whether
the
front
or rear
of
the
wafer
performs
the
particular
switching
function.
For
example,
a
wafer
designated
2R
indicates
that
the
rear of
the
second
wafer
is
used
for
this
particular
switching
function.
TABLE
4-1
Component
Numbers
Component
Numbers
on
Diagrams
Circuit
1-139
Sweep
Trigger
140-299
Sweep
Generator
300-399
Delay
and
Timing
Circuit
400-499
Readout
Logic
500-599
Horizontal
Amplifier
600-699
Seek
Circuit
700-899
Counter Circuit
900-939
Operating
Mode
Power
940-969
Delayed
Sweep
Magnifier
Control
970-999
Readout
Board
Circuit
Boards
and
Cards.
Fig.
4-6
through
4-13
show
the
circuit
boards
and
cards
used
in
the
Type
3B5.
Fig.
4-5
shows
the
location of
each
board
within
the
instrument.
Each
electrical
component
on
the boards
is
identified
by
its
circuit
number.
The circuit
boards
and
cards are
also
outlined
on
the
diagrams
with
a blue
line.
These
pictures
used
along
with
the
diagrams
will aid in
locating
the
com
ponents
mounted
on
the
circuit
boards
and
cards.
Wiring
Color-Code.
All
insulated
wire
and
cable
used
in
the
Type
3B5
is
color-coded
to
facilitate
circuit
tracing.
Signal
carrying
leads
are
identified
with
one
or
two
colored
stripes. Voltage
supply
leads are
identified
with
three
stripes
to
indicate
the
approximate
voltage using the
EIA
resistor
color code.
A
white
background
color
indicates
a
positive
voltage
and
a
tan
background
indicates
a
negative
voltage.
Table
4-2
gives
the
wiring
color-code
for
the
power-supply
voltages
used
in
the
Type
3B5.
Resistor
Color-Code.
In
addition
to
the
brown
composi
tion
resistors,
some
metal-film
resistors
(identifiable
by
their
gray
or
blue
body
color)
and
some
wire-wound
resistors
(usually
light blue or
gray-green)
are
used
in
the
Type
3B5.
The
resistance
values
of
wire-wound
resistors
are printed
on
the
body
of
the
component.
The
resistance values
of
com
position
resistors
and
metal-film
resistors
are
color-coded
on
the
components
(some metal-film resistors
may
have
the
value
printed on
the
body)
with
the
EIA
color-code. The
color-code is read starting
with
the
stripe
nearest
the
end
of
the
resistor.
Composition
resistors
have
four stripes
which
consist
of
two
significant
figures,
a
multiplier
and
a
tolerance
value
(see
Fig.
4-1).
Metal-film
resistors
have five
stripes
consisting
of
three
significant
figures,
a
multiplier
and
a
tolerance
value.
Power
Supply
Wiring
Color-Code
TABLE
4-2
Supply
Background
Color
1st
Stripe
2nd
Stripe
3rd
Stripe
4-300
volt
white
orange
black
violet
4-125
volt
white
brown
red
brown
-12.2
volt
tan
brown
red
black
—
100
volt
tan
brown
black
brown
Capacitor
Marking.
The
capacitance values
of
common
disc
capacitors
and
small
electrolytics
are
marked
in
micro
farads
on
the
side
of
the
component
body.
The
white
ce
ramic
capacitors
used
in
the
Type 3B5
are
color
coded
in
picofarads
using
a modified
EIA
code (see Fig.
4-1),
Diode
Color
Code.
The
cathode
end
of
each
glass-
encased
diode
is
indicated
by
a
stripe,
a
series
of
stripes
or
a
dot.
For
most
silicon
or
germanium
diodes
with
a series
of
stripes,
the
color-code
also
indicates
the
type
of
diode
and
identifies
the
Tektronix
Part
Number
using
the
resistor
color-code system
(e.g.,
a diode
color-coded
blue-brown-
gray-green
indicates
diode
type
6185
with
Tektronix Part
Number
152-0185
-00).
The
cathode
and
anode
end
of
metal-
encased
diodes
can
be
identified
either
by
the
diode
symbol
marked
on
the
body
or
by
the
flared
end
at
the
anode.
Troubleshooting Equipment
The
following
equipment
is
useful
for troubleshooting the
Type
3B5.
1. Transistor
Tester
Description:
Tektronix
Type
575
Transistor-Curve
Tracer
or
equivalent.
Purpose:
To
test
semiconductors
used
in
this
instrument.
2. Volt-ohmmeter
Description:
20,000
ohms/volt.
0
—500
volts
DC.
Accurate
within
3%.
Test
prods
must
be
well
insulated.
Purpose:
To
check voltages
and
for
general
troubleshooting
in
this
instrument.
3.
Test
Oscilloscope
Description:
DC
to
20
MHz,
50
millivolts
to
50
volts/divi-
sion
with
10X
probe.
Purpose:
To
check
waveforms
in
this
instrument.
4-2
Summary of Contents for 3B5
Page 4: ...Fig 1 1 Type 3B5 Automatic Programmable Time Base unit Type 3B5...
Page 15: ...Operating Instructions Type 3B5 TYPE 3B5 CONTROL SET UP CHART Fig 2 2 Control set up chart 2 7...
Page 48: ...CO I o Fig 3 13 Delay and Timing Circuit logic block diagram Circuit Description Type 3B5...
Page 61: ...GO i GO GO Fig 3 22 Seek Ciicuit Logic block diagram Circuit Description Type 3B5...
Page 70: ...u k KJ Fig 3 29 Circuit conditions for Manual Mode operation Circuit Description Type 3B5...
Page 71: ...w K w Fig 3 30 Circuit conditions for Seek Mode operation Circuit Description Type 3B5...
Page 72: ...w I u U Fig 3 31 Circuit condition for External Mode operation Circuit Description Type 3B5...
Page 88: ...Maintenance Type 3B5 Fig 4 9 Location of components on Logic Card 4 14...
Page 89: ...u Oi Fig 4 10 Location of components on Counter Card Maintenance Type 3B5...
Page 92: ...NOTES I...
Page 104: ...NOTES...
Page 106: ...Calibration Type 3B5 Fig 6 1 Recommended calibration equipment...
Page 160: ......
Page 176: ...J400 RtADOUT BOARD 3B5 PLUG IN A READOUT...
Page 182: ...397 R E A D O U T B O A R D 10 6b READOUT BOARD...
Page 184: ...FIG 1 FRONT SWITCHES TYPE 3B5 AUTOMATIC PROGRAMMABLE TIME BASE...
Page 185: ...FIG 2 CHASSIS REAR 3 GS to TYPE 3B5 AUTOMATIC PROGRAMMABLE TIME BASE...
Page 186: ...OPTIONAL ACCESSORIES...
