1. Attenuator
Compensation
The
attenuator
is
compensated
to
make
the
ac
attenuation equal
to
the
de
attenuation.
a.
Connect the
square-wave
generator
to
INPUT
1.
b.
Set
the
square-wave
generator to
1
kc
and
view
five
or
six
cycles
on
the
screen.
c.
Set
the
VOLTS/CM
switch
to
the
positions
indicated
and
adjust
each
capacitor
in
the
following
table
for
a
square
corner
on
the
square
wave.
The
capacitors
are
identified
by numbers
on
the
chassis
just
above
the
attenuator
switch.
VOLTS/CM
.1
.2
.5
5
.2
CAPACITOR
C306
C312
C316
C320
(Serial
Number
101-1000)
VOLTS/CM
CAPACITOR
C306
.5
C312
1
C316
10
C32O
2. Input-Capacitance
and Probe Adjustment
The
probe
is
used to
set
the
input
capacitance
of
all
the
attenuator
positions
to
the
same value.
a.
Connect
the
probe
to
INPUT
1.
b.
Connect
the
output
of
the
square-wave
generator
to the
probe.
c.
Set
the
VOLTS/CM
switch
to
the
positions
indicated
and
adjust
each
capacitor
in
the
following
table
for a
flat top
on
the
square
wave.
VOLTS/CM
CAPACITOR
.05
.1
.2
.5
Probe
Trimmer
C305
C311
C315
5
C319
(Serial
Number
101-1000)
VOLTS/CM
CAPACITOR
.1
.2
.5
1
10
Probe
Trimmer
C305
C311
C315
C319
High-Frequency
Compensation
The
vertical-amplifier
high-frequency
com
pensation
is
adjusted
by
means
of
six
inductors
and
the
delay-line
trimmers.
These
adjust
ments
should
be
quite
stable.
Minor
adjust
ments
may
be
required
as tubes
are
changed,
however.
A
square-wave
generator
having a
risetime
of
12
millimicroseconds
or
better
should be
used
when
making
these
adjustments.
The
Tektronix
Type
107
is
recommended.
The
Tektronix
Type
105
is
satisfactory
if
pre
cautions are
taken
to
obtain
the
best
risetime
possible.
Refer
to
the
instruction
manual
for
these
instruments
for
information
on
the
proper
termination of the interconnecting
coaxial
cable.
a.
Connect
the
output
of
the
square-wave
generator to
INPUT
1.
b. Set
the square-wave generator
to
250
kc.
c.
Set
the
VOLTS/CM
switch
to
.05,
CALI
BRATED
(.2,
CALIBRATED
Serial
Num
ber
101-1000).
d.
Set
the
square-wave generator amplitude
for
about
4-cm
of
deflection.
e.
Set
the
TIME/CM switch
to
.5 /uSEC/CM.
f.
Set
the
TRIGGER
SELECTOR
controls
to
AC,
-1NT.
and
display
the
square
wave.
Misadjustment
of
the
coils
or
trimmers
will
be
indicated
by
spikes
or
wrinkles
starting
at
the top
corner
of
the
square
wave
and
extending
for
.5 microseconds
along
the
square
wave.
Disregard
the
bottom
of
the
square
wave.
g.
Start
with
C486
and
C485
located
near
the
neck
of
the
ert
and
work
toward
the
front
of
the
delay
line,
removing
any
wrinkles
which
are
present. Adjust
L485
and L486 in
sequence, leaving
them
AA
Recalibration
Procedure
- Type
515/515A
5-3
