Hi. I'm Chang.
I'm the Product Marketing Manager at Keysight Technologies.
Today, I will show you some unique capabilities of our Waveform Generators.
In this example,
I'm going to show you how easy to create two-tone signals
using a Trueform Waveform Generator.
I have a speaker connected to my function generator.
And in this video, you will be able to hear the signal tone
that I'm creating
and the noise that I will be
adding to the signal in the second portion.
This is a unique capability to this Waveform Generator.
Let me show you how to do it.
I will start by creating the first DTMF tone,
digit number one on the phone keypad.
The DTMF digit number one
consists of two frequency tones mixed together.
The first frequency tone is at 697 Hertz.
This single sinusoidal tone signals
is what it sounds like...
-Let's now add the second sinusoidal tone signal
at 1209 Hertz.
We do that with the Modulation menu.
There is a modulation type called “Sum”.
Within “Sum”,
we can set the frequency of the second tone and the amplitude.
So,
let’s set the frequency at 1209 Hertz.
We will set the amplitude at 100% compared to the first tone.
Now,
you can see the dual tone signal.
So, we have the dual tone signal created now.
Now, let's put some additive noise into the dual tone signal
we have just created.
We can do that by using channel two
to create the noise.
We will turn on the noise.
The noise is set at 1 Volt peak-to-peak.
-We will use the dual channel mode operation
to add the noise for channel two to the dual tone signal
we created in channel one.
We simply combine the two channels.
And now I have added
the noise to the dual tone in channel one.
So, let's look at the oscilloscope.
You can see just a little bit of noise on that waveform at this point.
Now, let's add under the noise.
-Let's increase the amplitude of the noise
just to show you a little bit more clearly.
So now, you can see that there is more noise on this signal.
You have the ability to adjust the level of the noise
on your two-tone signal.
Now, let's listen to this dual tone
with the noise.
You would notice that,
for us with our human hearing,
it mostly sounds like a dual tone.
However, electronic instruments
are much more sensitive
and are able to detect that noise.
So, with this noisy real world two-tone signal,
you can use it to test telecommunication receivers.
Particularly, for the DTMF receivers
which are mainly used at the telephone switching centers,
to detect the dialed numbers.
DTMF receivers
are also used in call centers,
IVR systems and security systems.
These systems can be used in industry application.
Thank you.