My Siglent SDG2042X True Arbitrary Function Generator

For the search for a decent signal generator I had no strictly fixed budget, but kept  rather certain requirements in my mind. It should be a 2-channel device with a clean (THD) behaviour.

Bandwidth wise almost everything higher than a few MHz suffices. A sensible GUI wouldn´t be bad either.

In this device categroy also it became quickly clear that A-brands do offer fantastic stuff, but much costier than I was willing to pay for. So I looked around at the two ´better´chinese suppliers Rigol and Siglent. Similar to the oscilloscopes the Siglent´s looks alone appears much better and more professional.

Sorry Rigol, but your frontplates and displays simply look childish and unprofessional. Shadings on the display characters like with the DG1000Z are simply stupidic chichi reducing the readability and useability. Siglents SDG1000X series is way ahead in this regard. The layout of the operating controls and the fonts are clean, clear, logical and the display is crisp and sharp.

Regarding their paper form both entry series were on par ... but then I took another look at the higher class and discovered the SDG2000X series of Siglent.

Well, the decision for the smallest of the three, the SDG2042X came fast.

Beeing 16Bit generators they allow for higher dynamics and signal purity  than the 14Bit generators.

The two channels of the Siglent are truely identical (Rigol´s aren´t). A very high samplerate and loads of memory for complex signal brought down to a round figure.

Furthermore I can control the Siglents not only via LAN but also from my Siglent scope via direct USB cable connection. This allows for the generation of Bode plots. Also in cooperation with the oscilloscope can you store and replay oscilloscoped waveforms on and from the function generator at any time.

As it turned out the three SDG2000X brethren differ only(!) in the software defined bandwidth for the sinus waveform. They are identical in all other respects. On Your wish the SDG2042X can be upgraded in bandwidth to 80Mhz or 120MHz with a software key (or hacking). You know, this isn´t even necessary, because the hardware is full bandwidth anyway and the generator is a Arbitrary- and DDS Generator. There´s a fully sufficient workaround in that one ´draws´ and stores a exact 10-cycle sine waveform snippet with the associated software EasyWave. This waveform can be replayed with up to 12MHz frequency. Factually the generator then puts out sine signals of up to 120MHz. Basically You can do the same with any other waveform too, but with squares You quickly reach ranges where the curves become too rounded.

Regarding the signal quality the generator clearly dives down below the 0.1% THD mark.

Due to specialized algorithms the risetime of pulses and squares stays minimal, just a few ns.

With common DDS generators the risetime increases with decreasing frequency.

The possibilty to couple both channel outputs in several ways allows for a useage as curve tracer and component tester also ... more on this in the section Curve Tracer.

As already noticed with the Multimeter the signal generator´s front face layout and display also bears great similarities to actual Keysight devices. Keysight´s 33500B model range with 20Mhz and 30MHz models would be the equivalent to the SDG2000X series. The prices for those soar between 2,560€ and 2,820€ ex.VAT, over 5x as much as the SDG2042X.

I very much doubt that the differences in capabilities and signal quality are equally large as the price differences. I am happy with my signal generator in any case.

Siglent is here too a OEM for TeledyneLeCroy and others.

Siglent  <----> TeledyneLeCroy

SDG2042X = T3AFG40

SDG2082X = T3AFG80

SDG2122X = T3AFG120 ... as usual the TLC devices are almost double in price.