Wavetek 132 Instruction Manual page 7

20.
Verify
that
NOISE
FREQ HZ
vernier control
provides
approximately 10:1 variation
in
clock
frequency
at
the
NOISE
CLOCK
connector
(rear panel).
21.
Rotate function
selector to
/
"
!
position
and
check
to
assure oscilloscope displays
analog
noise.
22.
Check
to assure
SEQUENCE LENGTH
push
buttons vary the
length
of the
sequence
of
analog
noise.
(Use
NOISE
SYNC
connector on
rear panel.)
23.
Connect
oscilloscope external trigger
cable
to
FUNCTION SYNC
connector
(rear panel)
and
Set
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il
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i
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24.
Set
S/N
—
N/S
(d B
)
selector to
—10
position
and
vernier control
fully
ccw.
25.
Depress
MODE
— FM
push button and check
to assure square
waveforms
are
frequency
modu-
lated
by analog
noise.
26.
Release
MODE
— FM
push button and
depress
MODE —
S/N
push button.
Check
to assure
square
wave and
analog noise are
mixed.
27.
Depress
MODE
—
N/S push button and
rotate
S/N
—
N/S
(dB) selector
ccw
through each
position,
checking
for
reduction
in
signal
level.
28.
Verify
that the
S/N
—
N/S
(dB) vernier attenu-
ates
the
signal
approximately 10 dB between
each
step of the
S/N
—
N/S
(dB)
selector.
OPERATING CONTROLS
The
operating controls and
electrical
connections
for
the
Model 132
are
shown
in
Figures 2-1
and
2-2.
Each
of the following paragraph
numbers corresponds
to
a
number
appearing
in
Figure
2-1,
front panel, or
Figure
2-2, rear panel.
The
listing
below
discusses
each
control
and
its
function.
FRONT PANEL
1.
FREQ
HZ/PWR OFF —
Selects
one
of
six
dec-
ade
ranges
from
X10
to
X1M
for generator
frequency. This value multiplied by
the
fre-
quency
dial
setting
(3)
gives
the output frequen-
cy of the generator.
Extreme ccw
rotation
will
place the switch
in
the
PWR OFF
position, turn-
ing off
all
power
to the function
and
noise
generators. This control has
no
affect
on
the
noise frequency.
2.
FREQ VERNIER
—
Allows
precision electronic
control of the
signal
output frequency.
A
full
turn
of
the control
is
approximately
equal
to
1%
of
full scale.
When
turned
to
the
full
cw
position
(CAL),
settings
on
the
main
dial will
be
cali-
brated.
3.
Frequency
Dial
—
Allows
coarse control of the
signal
output
frequency.
4.
Frequency
Index
—
Indicates
the
frequency
dial
setting
(3)
by
reading the
dial
position
opposite
the
scribe line
on
the
frequency
index.
The
in-
dex
is
illuminated
when
power
to
the
unit
is
on.
5.
Function
Selector
—
Selects the desired function
or noise output.
To
select
!
\j
,
'V
,
or
1
|j
waveforms,
or
JjJ
T_
or
nr
noise, the
FUNC
push button
(7)
must
be depressed.
6.
OUTPUT VERNIER
(dB)
-
Provides
vernier
control of
0 through
—20
dB
from
the
OUTPUT
ATTEN
(dB)
setting (12).
This
is
the
fine ad-
justment
for the
output
signal
and
will
attenuate
signal
and
noise.
MODE
7.
FUNC —
When
depressed,
this control allows
the
selected
waveform
or
noise, as
determined
by the position of the function
selector
(5),
to
be present
at
the 50fi
OUT
connector
(11).
This push button must
also
be
in
the depressed
position
for the
frequency modulation
mode
(
10
).
8.
S/N
—
Depressing
this
push button
allows
a
calibrated
amount
of analog noise
to
be added
to the selected
signal,
either
/
\j
,
'v
,
or
HL wave.
The
signal-to-noise ratio
(S/N)
is
determined by
the
S/N
—
N/S
(dB) attenuator
control
(13).
When
in
this
mode,
the
peak
to
peak
signal
amplitude
is
reduced
internally, since
adding
noise to the
signal
would
overdrive the
output
amplifier.
9.
N/S
—
Depressing this
push button
allows
a
calibrated
amount
of the
selected
signal, either
'\y
, ,
or
r
"|_j
wave,
to be
added
to
the
analog
noise.
The
noise-to-signal ratio (N/S)
is
determined by
the
S/N
—
N/S
(dB) attenuator
control
(13).
When
in
this
mode,
the peak
to
peak
signal
amplitude
is
reduced
internally, since
adding
the
signal
to the noise
would
overdrive
the output amplifier.
4