Description
The
RCA
WO-33A
is a 3-inch oscilloscope de-
signed for
"on-location"
and
service-shop use in
servicing color
and
black-and-white television re-
ceivers, Hi-Fi
equipment,
PA
and
sound reenforcing
systems,broadcast
station
and
remote equipment,
communications
and
industrial electronic equipment.
A novel feature of
the
WO-33A is
the
Vertical
Input
Attenuator
which
automatically switches
the
amplifier from
Wide
Band
to Narrow Band
when
in
the
three
highest
gain positions.
Another
important
feature of
the
WO-33A
is
the
exceptionally
high
gain in its vertical amplifier.
There
is enough sensitivity
to
provide a useful dis-
play of signals from low-level microphones, phono-
pickups
and
other
weak
signals found in radio/TV
receivers, audio amplifiers, etc.
A voltage-calibrated, frequency-compensated ver-
tical-input attenuator,
an
internal calibrating-voltage
source,
and
a
graph
screen scaled directly in volts
make
it
possible
to
use
the
WO-33A as a visual
voltmeter.
The
unique
system of calibrating the
graph
screen provides for scaling voltages directly
from
the
screen.
The
measurement
procedure
is
very
similar
to
that
employed
with
a vacuum-tube volt-
meter. A calibrating voltage
is
automatically applied
to
the vertical amplifier
when
the
bandwidth
control
is
set
to
the
calibration position. This switch also dis-
connects internally
the
input
and
attenuator
circuits,
making
it
unnecessary
to
remove leads
and
probes
from
the
external circuit
under
test. These unique
facilities make voltage calibration
and
measurement
a simple, almost
automatic
procedure.
The
sweep-frequency control
is
continuously
adjustable from 15 cps
to
75
Kc.
The
sweep oscil-
lator has excellent stability
at
high sweep rates, a
fast retrace,
and
adequate
linearity throughout its
frequency range.
The
over-all frequency range of
the
oscillator
is
divided
into four basic ranges; a
vernier adjustment,
which
overlaps
the
basic sweep
ranges, provides exact
adjustment
of
the
sweep fre-
quency.
The
amount
of sync signal
fed
to
the
sweep
oscillator may
be
adjusted
by
means of a front-panel
• 4 •
control. Sweep synchronization is exceptionally
stable throughout
the
sweep range
of
the oscillator.
A
phase
control is provided for varying
the
phase
of the internal sweep voltage
when
the
"LINE"
position of
the
H/SWEEP
SEL
cOlltrol
is
used, en-
abling
the
WO-33A to
be
phased
with
an
external
line-frequency sweep oscillator.
To
facilitate its use,
the
WO-33A is
equipped
with
a specially designed single-unit
probe
and
input
cable. This accessory,
the
WG-349A
DirectiLow-
Capacitance Probe
and
Cable, is provided
with
a
blue
input
lead
and
a yellow input lead.
When
the
blue
input
is used,
the
test signal
is
fed directly
to
the
vertical-input terminal.
When
the
yellow
input
is
used, a special high-impedance circuit
in
the
probe
is
connected in series with
the
test point
and
the
'scope. This high-impedance circuit presents
an
over-
all
input
resistance of 10 megohms
and
an
input
capacitance of approximately 10
ppf
to
the
test
cir-
cuit. This feature reduces circuit-loading effects
and
permits use
in
circuits which would not function
properly
if
loaded
down
by a conventional oscillo-
scope.
The
WO-33A
can
be
used to trouble-shoot
and
signal
trace
all sections of
both
black-and-white
and
color-TV receivers. The voltage-calibrating facil-
ities,
wide
band-pass,
and
high-impedance
input
characteristics make possible observations
and
meas-
urements of color-burst signals
and
othe'; critical,
,.
high-frequency waveshapes in circuits
which
are
sensitive to loading effects.
The
size
and
weight
of the WO-33A make
it
an
especially portable instrument, useful
in
such
appli-
cations as industrial maintenance
and
trouble-shoot-
ing, general waveform analysis, adjustment of
radio
receivers
and
transmitters, square-wave
and
general
testing of audio equipment, peak-to-peak voltage
measurements,
and
observation of
vacuum-tube
characteristics.
The
WO-33A is a versatile
and
re-
liable instrument, well suited to applications
which
require a
dependable
oscilloscope.
Specifications
NOTE:
Performance
figures
are
for
a line
voltage
of 117
volts,
60
cps.
Frequency
Response:
Electrical
Vertical Amplifier:
Wide-Band Positions (5.5 cps to 5.5
Mc)
..................................................... flat within - 3
db
High-Sensitivity Positions:
20
cps
to
150
Kc
..................................................... .
3 cps to 1.5 Mc .................................................... .
Horizontal Amplifier (3.5 cps to 350 Kc)
Deflection
Sensitivity:
Vertical Amplifier:
At
V
INPUT
connector .......................................
With
WG-349A Blue
Lead
With WG-349A
Yellow
Lead
..............
(Wide-Band)
Positions
rms
p-p
0.10
0.3
0.10
0.3
1.0
3.0
. ..... flat within - 3
db
flat within - 6 db
.... flat within - 6 db
(High-Sensitivity)
Positions
rms
p-p
.003
0.01
volt/in
.003
0.01
volt/in
.03
0.1
volt/in
Horizontal Amplifier
(at
H
INPUT
terminal)
Rise
Time
(Vertical Amplifier):
.......................................................................................... 0.9
rn1S
volt/in
5.5-Me
Positions
0.1 psec
Input
Resistance
and
Capacitance:
Vertical Amplifier:
At
V
INPUT
connector ......................... ................. ............... ...................... 1 megohm shunted by approx. 50
f.Lpf
With
WG-349A Blue Lead ...................... ....... ........ ........ ......
...
...
...... 1 megohm shunted by apf)fox. 90
f.Lf.L
f
\Vith \VG-349A Yellow
Lead
.................... . ................................. 10 megohms shunted by
ap~rox.
10
pf.Lf
Horizontal Amplifier
(at
H
INPUT
terminal) .................................................... . .....
io
megohms
EXT
SYNC
Input
Terminal........................ . .................................................................... 250 K to 55 K
Sweep
Oscillator:
Frequency Range (continuously adjustable)
Sync ................................... .
Sync
Range.
Maximum
AC
Input
Voltage
(at
Lo-Cap
Probe):
(In
presence of 400 volts
dc)
............................ .
Phase-Control
Range
.............................................. .
Power
Requirements:
Voltage ....
Average
Power Consumption .................................... .
1-6BR8
1-6BK7A
Tube
Complement
2-12AT7
Height
Width
1-6X4
Mechanical
8
31f1
14
6
1111
12
• 5 •
Length
Weight
15 cps to 75
Kc
........................ External; ± Internal
...
To
4.5 Mc
.....
600 p-p volts
o to 160 degrees
105-125 volts, 50-60 cps
. ...........
50 watts
1-6C4
1-3AQPl
.......
lOW'
14 lbs
To Next Page
Loading...