Signal Termination; Continuous Operation - Wavetek 183 Manual

@
VCG
lnput Connector
DC voltage excursions
of 0 to t5
volts
at
the
VCG
lN
connector control frequency
within
the
selected range. Positive inputs
increase frequencies
set
by
the frequency
dial @
and
range
control
@
,
and negative
inpu ts
deirease the
f
requencies.
lnput
impedance
is
5
ke).
Frequency excursions
of
1000:
1
are possible.
3.2
OPERATION
Operation
is
discussed
in terms of
the
f
ive
generator
modes:
continuous, triggered, gated,
sweep
and XCG
(crystal
con-
trolled) plus VCG (voltage
controlled).
3.2.1
Signal
Termination
Proper signal termination, or
loading,
of the generator
con-
nectors
is
necessary
for
its specified operation. For
example,
the proper termination
of
the
main
output is
shown
in
figure 3-6.
Placing the 50S) terminatclr,
or
50S)
resistance,
in
parallel
with
a higher
impedance matches the receiving
instrument
input
impedance
to
the
generator output
im-
pedance, thereby minimizing
signal
ref
lection
or power
loss
on the line due to phase angle
mismatch.
MODE
L
183
RECEIVING
I
NSTR UM
E
NT
Figure
3-6.
Signal
Termination
The
input
and
output
impedance of the generator connectors
are listed below:
3.2.2
Continuous Operation
Basic,
or
continuous, operation
of
the generator
involves
turning
on
power,
selecting
a
continuous
output
mode,
selecting
a
waveform, and setting the
output
signal
frequency
and amplitude. When
operation
is
critical, allow
a one-half
hour warm-up period. The following
steps demonstrate
use
as a basic
function
generator:
Step
Control/Connector
1
5OQ OUT
2
PU LSE
OUT
GEN MODE
WAVEFORM
SYMM ETRY
FREO
Frequency
Dial
FREO VERNIER
AMPLITUDE
AMPLITUDE
VARIABLE
DC OFFSET
Setting
Connect
circu
it (refer
to
paragraph 3.2.1l,.
Use
for
external
synchro-
nization, if required.
CONT.
Choose one
of the
lef
t-hand
set
of
waveforms.
lf
dc
or
dc
of
fset is
desired,
use
right-hand
set.
NO
RMAL
or desired
asyrn-
metry.
(Affects
frequency
calibration.)
As
desired
for
frequency
range.
As
desired
for
exact
fre-
quency.
CA
L,
u
nless higher
than
normal frequency
accuracy
is
required
at
a
non-XCG
frequency,
in
which
case,
monitor with
a
frequency
cou
n
ter.
As desired.
As desired
(20 dB
range).
As
desired (step
4,
right-
hand
set of
waveforms
must be chosen). CW posi-
tive offset,
CCW
negative
offset.
See
figure 3-7 for
restrictions.
Connector
50r)
Our
TR
IG
IN
PU
LSE
OUT
(TTL)
SWP
OUT
VCG
IN
GCV OUT
lmpedance
50Q
10
kr)
600[2
5kr}
1
ks)
11
*The
PU LSE
OUT connector
can
drive up
to
20 Transistor-Transistor
Logic
(TTL)
loads
(low
level between 0V
and
0.4V, and high
level
between 2.4V and
5V).
3-5
OUTPUT
IMP EDAN CE
OUTPUT
AMPLIFIER
(SIGNAL
LOAD
)
sosl
LoAD
RG58
OR
EOUIVALENT
EFFECTIVE
CIRCUIT
R ES
ISTANC
E