GwInstek GFG-3015 quick start guide:
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To clear all settings (RESET):
To RESET the signal generator: press "SHIFT" and
then "RS-232/DEFAU." This will set the signal generator to a
10 KHz sine wave with 5 V peak output (if no load). This will
also clear any other unusual settings a previous user might
have made.
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To control the MAIN output:
The MAIN output can produce signals up to 15 MHz with up to
10 volts peak-to-peak open circuit voltage. The actual (peak-
to-peak) open circuit source voltage for the MAIN output
is TWICE the displayed amplitude. If the load resistance
attached to the signal generator is 5000 Ω or more, then
just set the displayed output for HALF of the desired peak-to-
peak output voltage. For example, if you want a sine wave
such s 4.00sin(1000*2*pi*t) volts, which is an 8 V peak-to-
peak sine wave, set the amplitude to 4 Vpp.
The MAIN output has an internal 50 Ω Thevenin resistance
in series with it. (The 50 Ω resistor is inside the signal
generator. You cannot avoid it.) If the load attached to the
signal generator is less than 5000 Ω, then this resistance may
cause the signal voltage at the MAIN terminals to be less than the
open circuit voltage. In fact, if the load is 50 Ω, that is,
matched to the signal generator, then the displayed peak-to-peak
amplitude is the correct terminal voltage and the peak-to-
peak open circuit voltage is, as always, twice the displayed amount.
WAVEFORM:
1.) First, be sure "modulation" and "trigger" are not turned on.
Look in the lower left corner of the display for the "MOD/SWP"
rectangle. In there look for the "ON/OFF" display. The little
circle should be dark. If there is a green indicator lit, press
the large grey "MOD ON" button to turn the modulation off.
2.) To the left of the "MOD/SWP" box on the display there is a
"TRIG" box. If the "ON/OFF" indicator here is not dark, press
the white "TRIG ON" button to extinguish the indicator.
3.) Look along the very top row of the display. The waveform is
displayed here just to the right of the word "FUNC." A sine,
triangle, or square wave may be selected by pressing the large
grey "FUNC" button. Every press of the "FUNC" button changes the
waveform.
4.) Press "DUTY." The word "DUTY" blinks in the display to
indicate that you may now change the duty factor. Normally you
will want a 50% duty factor and normally that will be the
default--in which case you may go on to the next step. There are
two ways to change the duty factor when the "DUTY" indicator is
blinking in the display:
Press number buttons and then "DEG %." (The units are %.)
or
Rotate the knob.
The duty factor may be anything from 20% to 80% at
frequencies up to 1 MHz. Above 1 MHz duty factors other
than 50% are not supported but can be set, usually causing
frequency errors.
FREQUENCY:
Press the large grey "FREQ" button. The word "FREQ" blinks in
the display to indicate that you may now change the frequency.
There are two ways to change the frequency:
Press number buttons and then a units button such as
"MHz dbm" or "KHz Vrms" or "Hz Vpp"
or
Rotate the knob.
The frequency may be anything from
0.01 Hz to 15.0 MHz
AMPLITUDE:
Press the large grey "AMPL" button. The word "AMPL" blinks in
the display to indicate that you may now change the amplitude.
There are two ways to change the amplitude:
Press number buttons and then a units button such as
"MHz dbm" or "KHz Vrms" or "Hz Vpp"
or
Rotate the knob.
The amplitude may be set for:
0.01 Vpp to 10.0 Vpp or
0.01 Vrms to 5.00 Vrms or
-32.9 dBm to +26.9 dBm
The above assumes the offset is zero. (See OFFSET, below.)
The output voltage is only accurate if there is a 50 ohm load
connected. If the there is no load or if the load is greater
than 5000 ohms, then the output will be twice the
displayed amount. (e.g. you set 5.00 Vpp. With no load you
will actually have 10.00 Vpp.)
OFFSET:
Press the large grey "OFFSET" button. The word "OFFS" blinks in
the display to remind you that you may change the DC offset.
There are two ways to change the DC offset.
Press number buttons and then "Hz Vpp"
or
Rotate the knob.
The magnitude of the offset decreases the maximum available
amplitude and vice-versa. The sum of the magnitude of the
offset plus half the peak-to-peak amplitude (as displayed on
the face of the signal generator) must always be less than or
equal to 5.00 volts. (If you enter the amplitude in volts RMS
or dbm then a more complicated relationship holds. Distortion
is also possible if the equivalent peak voltage and the offset
magnitude add up to more than 5.00 V.)
The maximum range of the offset is
-4.99 V to 4.99 V
if the amplitude is set to to its minimum, 0.01 Vpp.
The offset voltage is only accurate if there is a 50 ohm load
connected. If the there is no load or if the load is greater
than 5000 ohms, then the offset will be twice the
displayed amount. (e.g. you set a 2.00 V offset. With no
load you will actually have a 4.00 V offset.)
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How to use the KNOB
Generally, the knob will change the quantity indicated by a
blinking word on the display. Pressing the white "<<" or ">>"
buttons allows you to control which digit changes when you turn
the knob. Pressing "HOLD" disables the knob. When the knob is
disabled, "HOLD" is illuminated in the upper right corner of the
display. (The keypad still works when "HOLD" is on.) Press
"HOLD" again to re-enable the knob.
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To control the MOD output
The MOD output can be used as a second signal generator. It is
of lower quality than the MAIN output. The maximum frequency
is limited to 10 kHz. The amplitude is not adjustable. It has
an open circuit voltage of about 4 Vpp and a thevenin equivalent
source resistance of about 10 kΩ.
Note: To use the MOD output you usually DO NOT want to
turn the "modulator" on. Turn the modulation on if and only
if you want the MAIN output to be modulated by the MOD output.
If you do not understand what this is, you do not want MOD on!
Look in the lower left corner of the display for the
"MOD/SWP" rectangle. In there look for the "ON/OFF" display.
The little circle will be dark if the modulator is off. If it
has a lit green indicator, press the large grey "MOD ON" button
to turn the modulation off. (Unless you really do want the
modulator on.)
WAVEFORM
Look in the lower left area of the display for the "MOD/SWP" box.
The selected waveform is displayed here or "EXT" is displayed.
1.) If "EXT" shows, press "SHIFT" "RATE (MOD INT/EXT)" to
extinguish the "EXT" display and show a waveform instead.
2.) To change the waveform, press "SHIFT," then "SPAN (SOURCE)."
Every press of these two buttons changes the waveform. You
may select sine, triangle, or square waves.
3.) Press "SYM." "SYM" blinks in the display to indicate that
you may change the duty factor of the MOD output. Usually
you will want 50% duty. There are two ways to change the
duty factor of the MOD output.
Press number buttons and then "DEG %." (the units)
or
Rotate the knob.
The duty factor may be anything from 10% to 90%.
FREQUENCY
Press "RATE". "RATE" blinks in the display to indicate that you
may change the frequency (rate) of the MOD output. There are two
ways to change the frequency:
Press number buttons and then a units button such as
"MHz dbm" or "KHz Vrms" or "Hz Vpp"
or
Rotate the knob.
The frequency may be anything from
0.01 Hz to 10.0 KHz
AMPLITUDE
Not adjustable. Always close to 2.0 Vpp into a 10 kohm load or
4.0 Vpp into an open circuit.
OFFSET
Not adjustable. Always zero.