-
Hi All
I am looking for an Arbitrary Waveform Generator and Rigol looks like a reasonable value for money. Never worked with them close before, only simple sine wave sources. The primary intended application - HF (ham radio) and Audio experiments. The price tags are quite close, screen on DG4000 is much better and I see it as a bonus. Output Frequency wise they look identical and what confuses me - Arbitrary Waveform Length: 8Mpts vs 16kpts. How a higher model can have smaller count? Do they use different algorithm? Would I be able to digitize a voice/sound block good enough to run through an experimental setup (for audio projects)?
What is the general opinion around DG1000Z vs DG4000 for the same frequency?
Thanks a lot.
-
I'm sure other will chime in with more technical details but if digitizing and replaying voice is the main purpose I'd guess the 1062Z is the more suitable one due to the much longer waveform length. At 44.1kHz the DG4062 would only give you 375ms worth of audio while the DG1062Z would give you like 3 minutes....
With that said the 4062 series offers higher sample rate (500 vs 200MSa/s) and twice the output amplitude at (5Vpp vs 2.5Vpp into 50ohm) at 60MHz. It also more types of modulation.
One limitation in the 4000 series that has bitten me (I've got a 4162) is that you can't change the dutycycle of the square or pulse output without ending up with "gaps" in the output. I don't know if the 1000Z series is the same.
-
Thank you for you input, H.O
you are right, 375ms does not look great
Frequency sweep in audio band will help somehow and I have a feeling that bigger collection of modern modulations in conjunction with greater sample rate may be a serious argument.
Thanks again.
I hope to hear more opinions.
-
After looking into Pros and Cons ended up buying DG4102
for relatively small difference in $$$ between DG4062 and DG4102. It does all I need at this moment without hacking. Vendor gave me quite interesting note saying that firmware specs upgrade voids my warranty. Never planned though 
.
Cheers,
-
One limitation in the 4000 series that has bitten me (I've got a 4162) is that you can't change the dutycycle of the square or pulse output without ending up with "gaps" in the output. I don't know if the 1000Z series is the same.
Not quite sure what you mean by 'gaps', but the DG4000 series enforces a minimum pulse width and rise/fall time based on the frequency of the waveform. I guess this is because of the limited amount of sample memory available, or limited processing power to generate samples on the fly. For example, a 1kHz pulse limits the minimum pulse width to 3.125us. There is a work around if you need shorter pulses - simply set the frequency to an arbitrarily high value, enabling a very short pulse width, then enable a 1 cycle burst and use the burst period to achieve the desired frequency. E.g. Configure a 10MHz, 8ns pulse, enable Burst at 1cycles, 1ms period - now you have a 1kHz pulse waveform with an 8ns width.
Achieving finer resolution of the duty cycle for a square wave can be achieved the same way by manipulating the frequency of the square wave and using the burst period to set the actual frequency.
Another limitation I've found with my DG4062 is that the external modulation inputs seem to be digitally sampled at about 8bit so the dynamic range isn't that great. A Tek AFG3000 seemed to work as if it were analogue in the same application (phase modulating a 1-10kHz sine wave) -
Quote
Not quite sure what you mean by 'gaps', but the DG4000 series enforces a minimum pulse width and rise/fall time based on the frequency of the waveform.
No, I'm not talking about the limitation of not being able to set the dutycycle to "extreme" values. I'm talking about the fact that the output "stops" for a brief (~6ms) period whenever you change the dutycycle. I'll attach an images showing what happens, here I'm changing the dutycycle of the squarewave output from from 20% to 80% but the amount of change has nothing to do with it and the behaviour is the same on the pulse waveform.
Depending on what you're doing this can be a real showstopper and it's important to be aware of. I certainly wasn't when I bought mine and, as I said, it has caused me some grief. Like when testing a H-bridge for a motor controller, that didn't work very well when the "carrier" disappears for like 120 PWM cycles everytime the dutycycle changes.
-
I'm talking about the fact that the output "stops" for a brief (~6ms) period whenever you change the dutycycle. I'll attach an images showing what happens, here I'm changing the dutycycle of the squarewave output from from 20% to 80% but the amount of change has nothing to do with it and the behaviour is the same on the pulse waveform.
Many of the modern digital waveform generators (and some sold as function generators) have this same problem, it appears as though they use the arbitrary waveform memory and update it with a new "image" each time you adjust the controls, hence the gap in the output waveform.
Depending on what you're doing this can be a real showstopper and it's important to be aware of. I certainly wasn't when I bought mine and, as I said, it has caused me some grief. Like when testing a H-bridge for a motor controller, that didn't work very well when the "carrier" disappears for like 120 PWM cycles everytime the dutycycle changes. -
I also stumbled across a similar problem when generating signals to simulate an R/C (radio control) PPM signal, see here: https://www.eevblog.com/forum/testgear/annoying-bug-in-rigol-dg4000-series-function-generator/msg916154/#msg916154
It's amazing that the ugly and rather crude Hantek HDG2000 series AWGs don't show this problem (but several others instead... ). I'm not sure if I would recommend to get an AWG from Rigol at all. I don't know much about the DG1000Z series but from hear-say on this forum and elsewhere, the Siglent SDG2000X series is a decent alternative, even at a little lower price than the DG4000 competitor (and providing some hacking potential... 
).
Cheers,
Tom
-
Ahh, gotcha. This is a perfect application for the external modulation inputQuoteNot quite sure what you mean by 'gaps', but the DG4000 series enforces a minimum pulse width and rise/fall time based on the frequency of the waveform.
No, I'm not talking about the limitation of not being able to set the dutycycle to "extreme" values. I'm talking about the fact that the output "stops" for a brief (~6ms) period whenever you change the dutycycle. I'll attach an images showing what happens, here I'm changing the dutycycle of the squarewave output from from 20% to 80% but the amount of change has nothing to do with it and the behaviour is the same on the pulse waveform.
https://www.eevblog.com/forum/testgear/rigol-dg1062z-vs-dg4062/?action=dlattach;attach=369077
Depending on what you're doing this can be a real showstopper and it's important to be aware of. I certainly wasn't when I bought mine and, as I said, it has caused me some grief. Like when testing a H-bridge for a motor controller, that didn't work very well when the "carrier" disappears for like 120 PWM cycles everytime the dutycycle changes. Most if not all of the DG4000 competitors have the same problem. From memory the Tek AFG3000B does it too, but the dead time is smaller.
-
I also stumbled across a similar problem when generating signals to simulate an R/C (radio control) PPM signal, see here: https://www.eevblog.com/forum/testgear/annoying-bug-in-rigol-dg4000-series-function-generator/msg916154/#msg916154
It's amazing that the ugly and rather crude Hantek HDG2000 series AWGs don't show this problem (but several others instead... ). I'm not sure if I would recommend to get an AWG from Rigol at all. I don't know much about the DG1000Z series but from hear-say on this forum and elsewhere, the Siglent SDG2000X series is a decent alternative, even at a little lower price than the DG4000 competitor (and providing some hacking potential... ).
Cheers,
Tom
No need to prejudice one models behaviour based on different model, when we can measure...
From 10% to 50% duty cycle, DG1032Z.....
I can't see any discontinuity...
Regards,
Sinisa
-
DG1032Z
Duty cycle 20%/80%.
I can't see any discontinuity...
At 1,0 MHz, there is no discontinuity.
At 1,1 MHz, 3.5 ms gap.