Kenwood FG-273 User manual

CGOOMNA
FUNCTION GENERATOR
G-273
INSTRUCTION MANUAL
KENWOOD CORPORATION
3833

TABLE OF CONTENTS
INTRODUCTION
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FEATURES
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PRECAUTIONS
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SPECIFICATIONS
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OPERATOR’S
CONTROLS
AND
INSTRUTONS
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A product ot
KENWOOD
CORPORATION
17-5, 2-chome, Shibuya, Shibuya-ku, Tokyo 150, Japan

INTRODUCTION
The MODEL FG—273 Sweep/ Function Generator
provides of a function generator, pulse generator, Sweep
oscillator, and frequency counter.
FEATURES
Wide—band design : seven ranges cover full oscillation
frequency from 0.02 Hz to 2 MHz
Selectable output of sine waves, square waves, and
triangular waves through one—touch operation.
TTL/CMOS square wave output connector facilitates
using TTL—level and CMOS-—level output square waves
as the signal source for experiment of a digital circuit.
The symmetry Function varies symmetry of saw—tooth
waves and pulse waves.
It can invert the wave polarity.
Equipped with a 6—segment LED oscillation frequency
display
and
a
counter
covering
the
range
from
5
Hz
to
10 MHz.
Applying
voltage
from
0
to
+10
V
to
the
VCF
IN
connector
implements
external
sweep
as
well
as
output
frequency
control.
10.
The log sweep and linear sweep function provides
sweep frequency control up to max. 1000: 1. Sweep
frequency is variable from 0.5 Hz (2 seconds) to 50
Hz (20 milliseconds ).
Sweep
control
is
implemented
by
applying
sweep
signal
to
the
VCF
connector
from
an
external
device.
DC
voltage
(0
to
£10V)
can
be
overlaid
upon
output
waveform.
Combined
use
of
the
—20
dB
and
—40
dB
ATTENUA—
TOR
pushbuttons
and
the
continuous
attenuator
provides
maximum
attenuation
over
60
dB.
A small and light-weight case with convenient
carrying
handle,
which
also
serves
as
a
tilting
stand.

PRECAUTIONS
Do
not
use
the
FG—273
Function
Generator
under
the
3.
Do
not
repeat
switching
on
and
off
the
Generator.
following
conditions
:
—
Places
exposed
to
the
direct
sun
light
4.
Follow
the
instructions
in
section
“MAINTENANCE”
—
Very
hot
and
humid
rooms
if
the
supply
voltage
is
to
be
changed.
~
Rooms
with
excessive
mechanical
vibrations
—
Near
devices
which
irradiate
strong
magnetic
forces or pulse voltage
The
FG—273
operates
immediately
after
turning
on
power.
For
accurate
measurement,
however,
wait
until
it
warms
up
sufficiently
after
pressing
the
POWER
switch.

SPECIFICATIONS
<FREQUENCY CHARACTERISTICS >
GENERAL
Output Waveform « « « « Sine wave, square wave,
triang! wave, pulse wave, TTL
/CMOS~-level square wave, &
ramp wave
Oscillation Frequency Range « * 0.02 Hz to 2 MHz
7 ranges (1/10/100/1k/10k/
100k /1M)
Frequency Accuracy (1) « *Max. + 1/4 digits (Digital
display to output frequency )
Frequency Accuracy (2) * «+ 5% of full scale (0.2H to
2MHz) ( Frequency dial to
output frequency )
External Frequency Control ( VCF)
Input Voltage + * « « * 0 to +10 ; frequency
increases with positive
voltage, max. + 20 V (DC +
AC peak )
Frequency Variable Range « * * 1000: 1 or more
Symmetry Variable Range « * * * 1:1 to 40:1 or more
DC Offset > > © ¢ «© © £10V (open circuit)
+5V (into 500)
continuous variable
Polarity * * * © © © © Inverted or non—inverted
SINE WAVE
Distortion * * * * * * 1% or less (10 Hz to 100 kHz)
Output Frequency Response * * * Within + 1.0 dB up to
100 kHz (into 500 , at max.
output )
Output * * ¢ © ¢ © © © Variable
SQUARE WAVE
Symmetry « « « * © °* 3% or fess (at 100 Hz)
Rise/
Fall
Time
* * «
*
100
ns
or
less
(at
max.
output
level )
Output * « ¢ * * « « « Variable
TRIANGL WAVE
Linearity «+ * * * ¢ ¢ © 1% or less (at 100 Hz)
Output * * * ¢ ¢ ¢ « « Variable

TTL OUTPUT
Rise/Fall Time «¢ ¢ «© » © 25 ns or less
Output * °° *¢ «++ «© «TTL level
CMOS OUTPUT
Rise/
Fall
Time
«¢
« « »
*60
ns
or
less
Output
«*
+
+
«
©
«
© ©
©
Continuous
variable
from
+5
V to +15 V (High)
<SWEEP CHARACTERISTICS >
Internal
Sweep
* ¢ ©
©
©
©
Linear
or
logarithmic
Sweep
Frequency
*
+
« *
*
0.5
Hz
(2
sec)
to
50
Hz
(20
m
sec),
continuous
variable
Sweep
width
«
+
© ©
*
+
©1:1
to
1000:
1,
peak—peak
variable
and
continuous
variable
External
sweep
*
° *
©
©
»
By
means
of
VCF
input
6
<FREQUENCY
COUNTER
CHARACTERISTICS
>
Frequency
Range
+ *
«5
Hz
to
10
MHz
(10sec,
1
sec,
0.1
sec,
&
0.01
sec)
Accuracy
*
*
© ©
©
© «
Reference
clock
accuracy
£1
count
Stability
+
+ +
+ +
+
++
2x10
or
less(0
to
40°C)
Input
Sensitivity*
*
*
*30mV
r.m.s.
(5Hz
to
10
MHz)
Max.
Input
Voltage
*
°
150V
r.m.s
(at
1kHz)
Input
Impedance
«
«
«
*0dB:
Approx,
500kQ
—20 dB : Approx, 1IMQO
<OUTPUT
CHARACTERISTICS
>
Output
Voltage
+
*
*
*
20
Vpp
or
more
(
open
circuit
)
10
Vpp
or
more
(into
50©
)
Attenuator
*
*
*
+ *
»—20dB/—40dB
step,
or
continuous
variable
Impedance +« * ¢ © «© © §900+10%

<POWER SUPPLY >
Input
Voltage
* * *
*
°
100/120/220/240
VAC
+
10%
(Max.
250V
AC)
Frequency °° * * © ° * 50/60 Hz
Power
Consumption
*
¢
Approx.
20
VA
<ENVIRONMENTAL
CONDITIONS
>
Storage
Temperature
*
*~—20
to
60°C,
70%
or
less.
Operating
Temperature*
0
to
40°C,
80%
or
less
With
Specifications
+*
*
23
+5
°C,
70%
or
less
<SIZE & WEIGHT >
Dimensions
(WHD)+
*
240x
64x
190
mm
Weight» > ***-**° 1.8kg
< ACCESSORIES >
Instruction Manual « * 1
AC cables se 2222 1
Fuse (0.3AT)***e° 1
(0.2A) eeeee |

FRONT PANEL
OPERATOR’S
CONTROLS
AND
INSTRUCTIONS
OOM)
O®
©
OOOO
©
oooO6
Fig. 1
23)

@ POWER Pushbutton
Pressing this pushbutton turns on power. Counter
display lights up to indicate power is on.
(2) Counter Display
Digitally displays internal oscillation frequency or
frequency of external input signal.
@) OVER LED
Lights up when reading on the counter display
overflows.
@) GATE LED
Flashes when the gate is operating.
©),@) Hz/kHz LED
Indicate the unit of frequency, Hz or kHz, as well as
the decimal point when 10s, 1s, 0.1s, or 0.01s is
selected with the gate time selector switch assembly@.
@ FREQUENCY Control
Variable potentiometer varies frequency within the
range selected with the Freqoency RANGE selector
switch assembly @. The dial is scaled from 0.2 to 2.0.
SWEEP WIDTH/ PULL ON Control
Pulling the knob selects internal sweep. Rotating it
controls sweep width.
Pushing the knob selects external sweep, which is
implemented when external sweep voltage is applied
to the VCF input connector.
SWEEP RATE / PULL LOG Control
Controls sweep rate (sweep frequency) of the internal
sweep oscillator.
Pulling the knob selects logarithmic sweep.

10
ct) DUTY/PULL INV (Symmetry Adjustment/Polarity Selector) Knob
Controls symmetry of output signal.
Clockwise rotation varies the duty ratio from 1:1 to 40:1.
This
adjustment
makes
pulse
wave
of
square
wave,
ramp
wave
or
saw—tooth
wave
of
triangle
wave,
and
asymmetric
sine
wave
of
sine
wave.
Pulling this knob inverts the phase polarity.
Note : Note that controlling this knob changes frequency.
Counterclockwise
Counterclockwise
Clockwise
Clockwise
Rotation
Rotation
Rotation
Rotation
TTL Wave —
Fig.
2
Effect
of
INVERT
Pushbutton
with
respect
to
DUTY
Contro!
Knob
Setting

@) OFFSET/PULL ADJ Control
Pulling this knob admixes DC voltage with output signal.
Clockwise rotation admixes positive voltage.
Counterclockwise rotation admixes negative voltage.
Fig.
3
iillustrates
several
types
of
waveform
with
the
OFFSET
knob
pulled
and
50—ohm
load
connected.
Zero DC offset at max. signal level
Offset limit for non-—clipping signal
Positive DC offset Negative DC offset
Excessive offset
5V
Positive DC offset Negative DC offset
Fig.3 Application Example of DC Offset
11

(2) PUSH TTL Knob (CMOS Level Control Knob)
12
Pulling the contro! varies the level of CMOS square
waves from 5Vpp to 15 Vpp continuously.
Rotating the knob, if it is depressed, causes no
variation in the level of TTL square waves.
AMPLITUDE Control
Rotating this control varies amplitude of output
waveform.
Frequency Range/Gate Time Selector Switch Assembly
Selects the following seven ranges of oscillation
frequency or four ranges of gate time :
X11: 10s 0.2Hz to 24Hz
X10: 2Hz to 20 Hz
X100: 1s 20Hz to 200 Hz
X1k: 0.2 kHz to 2 kHz
X10k : 0.1s 2kHz to 20 kHz
eae e |} 0.018 20 kHz to 200 kHz
X1M: : 0.2MHzto 2 MHz
COUNTER EXT Selector Pushbutton
Pressing the pushbutton (button engaged ) selects
external input frequency. Another press (button
released ) selects internal oscillation frequency.
dé) COUNTER —20 dB Pushbutton
Pressing the pushbutton attenuates counter input
signal by 20 dB.
4),48) ATTENUATOR Pushbuttons
Pressing these pushbuttons attenuates output signal
by 20 dB and 40 dB respectively.
FUNCTION Selector Switch Assembly
Selects
output
waveform
out
of
sine
wave
(“_),
triang! wave (“ ), and square wave (“,).
TTL/CMOS Output Jack
Outputs TTL—level or CMOS square waves.
EXT COUNTER Input Jack
Input jack for measuring frequency of external signal.
VCF Input Jack
By
applying
voltage
to
this
jack
in
the
state
where
the
WIDTH
pushbutton
@)is
depressed
(button
engaged
),
frequency
of
output
signal
can
be
varied.
Application of voltage from 0 to 10V varies
frequency up to max. 1000:1.
OUTPUT Jack
Outputs
sine
wave,
triang!
wave,
or
square
wave
selected
with
the
FUNCTION
selector
switch
assembly
,

REAR PANEL
Fig. 4
@ Power Connector
Connector for supplying AC power.
Use the dedicated power cord.
@® Fuse Holder
Fuse holder for AC power supply.

MAINTENANCE
1. Fuse Replacement
If the fuse has blown out, find out and eliminate the cause.
Then,
replace
it
with
a
new
fuse.
Use
a
0.3
A
slow—blow
fuse
for
supply
voltage
of
100
to
120
V,
or
a
0.2A
fuse
for
supply
voltage
of
220
to
240
V.
Fuse
holder
is
provided
on
the
rear
panel
of
the
unit.
2. Changing Supply Voltage.
WARNING
:
Prior
to
opening
the
case,
be
sure
to
disconnect
the
power
cord
from
the
socket.
2-1 How to Remove Case
To
open
the
case,
turn
the
unit
upside
down,
and
remove
four
screws
from
the
case
base
plate.
(See
Fig.
5.)
Then,
lift the base plate to detach it.
2-2 How to Change Supply Voltage
The
FG-273
is
available
for
supply
voltage
of
100,
120,
220,
and
240
VAC,
50/60
Hz.
To
change
the
supply
voltage,
remove
the
case
(in
accordance
with
item
2—1
above),
and
reconnect
the
voltage
selector
plug
on
the
printed
circuit
board
in
the
unit
to
a
desired
voltage
position
on
the
voltage
terminal
board.
(See Fig. 6.)
14

Power transformer
Screws (4)
Rubber shoe
Fig. 5 Disassembly and Assembly of Case
.
LP Voltage selector plug
Voltage terminal board
Fuse side
Rear side
|
|
Front side
Fig. 6 Internal selection of Supply Voltage
16