Siglent SDG2042x arbitrary function generator

[F6FLT]

Hi all

Almost every time electronic circuits are used, I see many of us who have designed a circuit specifically to generate a particular signal, such as pulses, sin, bursts...
I understand that for those who want to save money or who are not especially involved or interested in electronics in the long term.
For the others, investing in an arbitrary function generator is the perfect solution that will save a lot of time, while improving accuracy, versatility and reliability.

My goal here is only to provide a feedback on my equipment and a highly economical tip...

In some Chinese brands, the devices are part of series and all those of the same series are materially the same. Only the firmware limits the possibilities of the devices as you go down in the series.
On the EEV blog, I found a way to change the firmware of the Siglent 2042X generator. That's why I bought it recently:
https://www.siglent.eu/sdg2042x.html

It is the first of the 2000 series, its maximum frequency is 40 MHz. But the top of the series is the SDG2122X which goes up to 120 MHz:
https://www.siglent.eu/sdg2122x.html

I applied the EEV blog firmware to my SDG2042x 40 MHz and got a SDG2122X 120 MHz (see pictures)! Only the serial number was lost. We can put the old one back but I didn't succeed, my skill in linux is limited and anyway there is no technical interest in doing so.

My tests confirmed the 120 MHz operation, there is no attenuation at this frequency (one can even increase to 145 MHz but with level reduction, the theoretical maximum frequency being 150 MHz due to the DAC converter at 300 MSa/s (it is specified "1.2 GSa/s" but it is at the price of 2 additional bits added to the real 14 bits DAC to smooth transitions).

Connected to a PC via ethernet or USB, any waveform can be supplied to the device. We use dedicated software to generate waveforms and transfer them, but we can also generate them from an Excel file, that is what I did.
Thus, for example, I was able to generate the shortest possible pulse for this device, with an arbitrary duty cycle (which is not possible if only the standard "pulse" signal of the generator is used).
I also used it to produce a multi-sin signal to generate several carrier frequencies and transmit simultaneously in LW, MW, SW radio bands and also in FM on the second channel of the Siglent, all carriers being modulated from an external input.

This kind of device is really all we need in electronics to experiment! Note that I am in no way related to this brand, I have no personal interest in advertising it. I'm just satisfied (it's rare enough to report it  ).

[ayeaye]

Yes that's right, generating signal is always a problem, so signal generator were a bless. Siglent is also the cheapest reasonable tools one can get in europe at least. Too expensive and only a dream for me though.

What you used it for though, finding a resonant frequency. I noticed that is is no problem to see the resonant frequency even when using only square pulses, as the oscillation on the resonant frequency shows just everywhere. Why i found the resonant frequency important, was to choose the right length of the pulse, so it charges the capacitance during the pulse, and discharges during the back-emf. see my ngspice simulation  https://overunity.com/17861/bifilar-pancake-coil-overunity-experiment/210/ .

[Turbo]

You can just program a $4 micro to do all of that and more.
Embedded is the right word.

[F6FLT]

What do you mean by "all of that and more"?

[ayeaye]

You can just program a $4 micro to do all of that and more.

For signal generation? An arm microcontroller can do that, but it's a hell of difficult to program it. And arduino, one needs to make a dac for it, 16 resistors? Just whatever way, too much work to do just to generate a signal, when a function generator can do all that out of the box.

My solution so far though is to only use positive square pulses, which i generate with arduino, and a transistor, looks like enough for everything by now. But this of course is because of my poverty, if i had plenty of money, i undoubtedly bought a signal generator.