Wavetek 132 - Section 2 Operation - Controls Continued; Sequence Length Controls; Rear Panel Connections

amplitude remains
constant, thus
giving cali-
brated 0
to
—50
dB
signal-to-noise
ratios. In the
N/S
mode,
the signal
is
attenuated
with the
noise
remaining
unchanged,
thus giving noise-
to-signal
ratios
from
0
to
—50
dB.
The steps
for
this
control are
indicated
in
black
numerals on
the front
panel.
14.
S/N
—
N/S
(dB)
Vernier
—
Allows a
calibrated
fine adjustment
of the S/N
—
N/S (dB) step
at-
tenuator
( 13).
This
control is
continuously
vari-
able over at
least
a
10 dB
range.
When added to
the coarse
control
(13),
this
amount
equals the
total S/N
or N/S
ratio.
Approximate values
ot
attenuation are indicated
in
red numerals on the
front panel.
15,
NOISE FREQ HZ
—
This range
control
selects
the clock
frequency, or
bandwidth
for the
digi-
tal, or analog noise, respectively. When using the
digital noise function, clock frequencies from
160
Hz
through
1.6
MHz (indicated in black
numerals
and letters on the front panel)
are
available. When
using analog noise or the S/N,
N/S
modes, the bandwidth of the analog noise
may
be
selected
from
10 Hz to 100 kHz (in-
dicated in red numerals
and
letters on the
front
panel). In
the
FM mode, this control
establishes
the bandwidth
of
the analog
noise
used for
fre-
quency modulation. There are four
detent
posi-
tions
with an overlapping
vernier control
(16).
With the
vernier
in the
full
cw position, the
clock frequency, or bandwidth, is
equal to the
value printed
to the
right of
the detent mark.
16,
NOISE FREQ HZ
Vernier
—
As
mentioned in
number
15,
this
control
provides
a
continuous,
fine
control between the detent
positions
of
the
coarse
control. When
in the full
cw position,
the clock frequency, or
bandwidth, is equal
to
the
value
appearing at the right of
the detent
mark.
As
the
knob is rotated
ccw,
the
clock
frequency, or bandwidth,
is decreased. In the
full
ccw position, the actual value will
be
at
least 10:1 (and
as
much
as
100:1)
lower than
the value
to the
right of
the detent
mark.
17. VCG IN
—
This connector allows
external
volt-
age control of function
generator
frequency.
Up
to 1000:1 frequency change
may be obtained.
A positive voltage increases
frequency
and
a
negative voltage
decreases frequency.
Refer
to
"Operation
as
a
Voltage Controlled
Generator.”
SEQUENCE
LENGTH
18.
2
10
—
1
—
Depressing this push
button will
provide
1,023
counts of
the
selected
clock fre-
quency,
or
bandwidth,
determined
by
the
NOISE FREQ HZ
controls (15
and
16),
for
generation
of
a
digital,
or
analog noise pattern.
At the end of each
sequence,
the pattern is
automatically repeated.
19. 2
15
—
1
—
Depressing this push button will
provide
32,767
counts of the selected clock
frequency,
or bandwidth, determined by the
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generation
of
a
digital, or analog noise pattern.
At the
end
of each
sequence, the
pattern
is
automatically
repeated.
20. 2
20
—
1
—
Depressing this push button
will
provide
1,048,575
counts of
the
selected
clock
frequency, or bandwidth, determined by
the
NOISE
FREQ
HZ controls
(15
and
16),
for
generation of
a digital,
or analog noise pattern.
At the end
of
each sequence, the pattern is
automatically repeated.
REAR PANEL
21.
DC
OFFSET
—
This control
adjusts
the
±5 V
base
line
above or
below ground (±2.5
V offset
into
50^2
load).
The OFF position
gives
normal
vertical
symmetry. Peak amplitude is limited
by
the dynamic range of the amplifier
output.
22. FUNCTION
SYNC
—
This connector provides a
synchronizing
signal output at the same
fre-
quency of the
main
generator; that is, at the
same frequency
as
the sine,
triangle or square
wave.
The amplitude is greater
than 1 V
peak to
peak
square wave into open circuit at 600^2
output impedance.
23. NOISE
SYNC
—
This connector provides
a
syn-
chronizing
output
signal for monitoring the dig-
ital or analog
noise. A sync signal
is
generated at
the
beginning of each repetitive
cycle for the
selected
sequence
length
of digital
or
analog
noise.
24.
NOISE
CLOCK
—
This connector
provides an
external
output
of
the basic clock frequency
used
to generate
the digital
sequence
and
analog
noise.
6