Wavetek 132 Instruction Manual page 11

b.
For
increasing
frequency sweep with
positive
dc
input,
set dial
to
lower frequency
limit.
c.
For
decreasing frequency
sweep
with
nega-
tive
dc
input, set dial to
upper frequency
limit.
6.
To
sweep
the
audio range
from 20
Hz
to
20
kHz,
set
the controls to
20 Hz
as follows:
a.
Set the
main
dial
to 0.02.
b.
Set the frequency
vernier to the
full
ccw
position.
c.
Introduce
a
0
to
+5 V ramp
into
the
VCG
input'connector.
The
maximum
frequency which
may
be obtained,
when
using the
VCG
input,
is
the range
multiplier
times the
value
at
the
top
of the
dial (2.0).
The
minimum
fre-
quency
is
the range multiplier times the value
at
the
bottom
of the
dial
(0.002
—
frequency
vernier
must
be
in
ccw
position).
Verify
this
using the
nomograph
in
Figure
2-3.
MAIN
DIAL
VCG
IN
50HOUT
SETTING
VOLTAGE
FREQUENCY
Figure 2-3
-
VCG
Voltage-to-Frequency
Nomograph
In
example
1,
the
dial
is
set
at 1.0
and 0
voltage
is
applied
to
the
VCG
input.
Extend
a straight line
from
1.0 (dial setting)
through 0
voltage
(VCG
voltage)
and
obtain a
dial
frequency
of
1.0.
For
the
total
output
frequency, multiply the range by
1
with the
same
dial
setting.
Example
2
shows
the
results of using
a
ramp
from
—1
volt to
+2.5
volts for the
VCG
voltage. This
results
in
a
swept output from
0.6 to 2.0
on
the
dial.
Remember
to multiply the
dial
times
the range.
Operation
as a Calibrated Signal-to-Noise Source
1.
Select the desired
siqnal
waveform
bv
settina
function
selector to
f
\j
,
A^
(
or
Tl-
2.
Set
frequency
dial
and
FREQ
HZ
range
multi-
plier
for desired
signal
output frequency.
3.
Depress
MODE
—
S/N
push
button.
4.
Select noise
bandwidth by
setting
NOISE
FREQ
HZ
control to desired range
and
fine adjusting
bandwidth by
turning the noise
frequency
Hz
vernier control.
5.
Select desired
SEQUENCE LENGTH
by
de-
pressing appropriate
push
button.
6.
Select
signal-to-noise ratio
by
setting
S/N
—
N/S
(dB) control to appropriate attenuation
position
and
fine adjusting
attenuation
to desired
value
with
S/N
—
N/S
vernier control.
7.
Select
total
output amplitude by
setting
OUT-
PUT
ATTEN
(dB) control to appropriate
atten-
uation position and
fine adjusting
signal
to de-
sired
amplitude with
OUTPUT VERNIER
(dB)
control.
Operation
as
a
Calibrated Noise-to-Signal Source
1.
Select the desired
signal
waveform
by
setting
function
selector to
r
\j
,
A^
f
or 1l
2.
Set frequency
dial
and
FREQ
HZ
range
multi-
plier for desired
signal
output
frequency.
3.
Depress
MODE
—
N/S
push
button.
4.
Select noise
bandwidth by
setting
NOISE
FREQ
HZ
control to desired range and
fine adjusting
bandwidth by
turning the noise
frequency
Hz
vernier control.
5.
Select desired
SEQUENCE LENGTH
by
depres-
sing
appropriate
push
button.
6.
Select
noise-to-signal ratio
by
setting
S/N
—
N/S
(dB) control
to
appropriate attenuation
position
and
fine adjusting attenuation
to desired
value
with S/N
—
N/S
vernier control.
7.
Select
total
output amplitude by
setting
OUT-
PUT ATTEN
(dB) control to appropriate
atten-
uation position and
fine adjusting
signal
to de-
8