Recommend to a Friend
Fully usable AWG at a very low price
4.0
It's quite amazing how, as technology progresses, you can get cheaper and cheaper test equipment. This time, it comes from the guys at Siglent.
This generator, cost-wise, is cheaper than the Rigol competitor (and it has a higher resolution DAC and more sampling memory). You can buy the 10MHz version for the cost of a similar DDS from some other brands. So, it's cheap. Is it good?
Well, mostly, it is:
The box comes with the most basic accessories, that is, a quick start guide, a CD, an IEC power cord and an USB cable. There's no BNC cables included, so buy your own. I recommend you get BNC cables stocked by Tequipment (not backordered) to avoid delays in your order. The quick start guide did not mention what's in the package. I had to get home and read the full PDF manual in the CD to check if my package was complete. I repeat, the box comes with:
*CD
*Manual
*According to the manual, a warranty card.
*USB cable
*IEC power cord
*The instrument
Great. When I opened the package I noticed the instrument looks very small. Which is nice. It didn't look that small in the photos. It looks small because the buttons are small, but they still, they are separated and have a nice feel to them. They can be pressed with your thumbs if you wish. The screen is readable as well.
There's a single knob. When you use it in software, the knob has no acceleration, that it, it increases the values but doesn't hurry up even after you spent a lot of time turning it. Also, the knob can be pushed but it seems to have no function that I know of.
Another thing that gets me is that, on the front panel, the colors of the output are light blue and yellow-orange, but in the user interface it's green and yellow. It's close enough, but it gets me. Channel 1 is on the right, which is not normal.
The rubber feet are very grippy, the instrument doesn't slide around, there is no fan on the 5 and 10MHz units, all silent. The tilting bail is okay, but is tricky to move. The case can stand up vertically as well.
Finally, on the back there are 4 BNC connectors, these are for a 10MHz reference input and output, external modulation input and generator sync/trigger output. They are not isolated. The modulation input is not protected from overloads, do not exceed /- 6V. This is an oversight, they could at least have some clamping diodes (I hope they actually have them).
Now moving on to the user interface. It was easy enough for me to figure it out. It normally defaults to the same setting when you power it up, but that can be changed so that it remembers its last setting. It's quite typical user interface for a China design. You can store and recall configurations, load built in arbitrary waveforms, load arbitrary waveforms from a PC (more on this later). You get a preview of the waveform on the screen, even for arbitrary waveforms. I found no way of importing a CSV into the device from the USB port. I think all AWGs should import CSV and not only the export format of the brand's oscilloscopes. However, you can import generic CSVs from the PC, but I know this will be inconvenient for many people.
The software included for the PC, EasyWave, is very very basic. The waveform editing capabilities are limited. I would mostly use it for the equations editor. If I needed to create a waveform point by point, or needed to clip, resize or rearrange a waveform, I would use a different program, and import the CSV into Siglent's program. Let's hope that, as Siglent grows they will create a better PC software for all their AWGs and scopes. The device implement the USBTMC protocol, and it supports GPIB commands over that protocol. If you have experience with this, you could get away with your own software, but let's face it. This is a tool, not a project. Let's hope we get better software as Siglent grows as a company.
Moving on to the performance of the instrument. I have tested sweeps extensively. It the trigger output works as intended. There are internal and external sources for triggering the generator, including triggering the sweep by pressing a button on the device. Sweeping was the main reason I went for this and not a cheaper analog generator.
The sweeping can range from uHz (ridiculously low) up to the full bandwidth.
Speaking of bandwidth, there was barely any loss at the full bandwidth for the sine wave, so the -3dB point is higher than the claimed bandwidth, at least in my unit.
There is a known issue with low frequency square waver, where there can be jitter. Some users traced it down to a comparator inside the instrument, which had too little hysteresis for the low frequencies. A workaround is to use the pulse function. It should be the same, except you can't do sweeps.
I measures the rise time of the pulse and the square waves to be a little over 50MHz.
One important thing to know about modulation, the built in carrier frequency generation can be rather low, even for audio applications. AM modulation, for example, only goes up to 1kHz. A workaround it to use the second channel and the external modulation input as the modulation source. Of course, you lose the second channel. The external modulation input seems to me sampled at 500ksps for AM modulation, (a sample every 2?s), giving you a bandwidth of 250kHz, theoretically. Realistically, it's only usable at 50kHz, where you can see that the amplitude of Ch1 changes in 10 steps (evidently there is no filtering going on, aliasing can, and does happen). At 250kHz a sine wave on Ch2 gives you an AM modulated square wave on CH1.
Now instead of AM, I did FM, with an FFT on my oscilloscope to visualize the frequency steps. I used 1Mhz frequency deviation on a 5MHz wave. This time, with a 500kHz modulation, I see peaks at 4 and 6MHz. Basically FSK. So, this confirms that the sampling rate of the modulation input of the generator is 500ksps.
I also saw 2nd order harmonics on the modulation, but I cannot say where they come from, it could be my test setup, which is not the best. I'm not equipped to measure distortion.
One nice feature is that it can modulate adn sweep arbitrary wavefroms just like if they were sine waves, which is excellent.
The instrument also comes with burst capabilities, which I haven't tested.
Other functions it can generate, apart from the ones I've mentioned, include, ramps (triangle waves) up to 300kHz, white noise,
Conclusion:
Overall, for the price, it's a very good tool. It's an excellent alternative to an analog generator of a similar price. It has two channels! Sweep, modulation, burst, noise, arbitrary waveforms.
It does have some quirks but try the workarounds I suggested.
If you're really short on money, you could consider the SDG800 series (1Ch only, and doesn't have the square wave issue), but this SDG1000 is obviously better if you can afford it.
If your only purpose is to use it for arbitrary waveforms, you should think a little about how you're going to make your waveforms. Try the software first. For all other purposes it's excellent for the price, beats the competitors.
And don't forget the BNC cables. :)
Ivan747 on
Dec 29, 2014
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