Rigol DHO914S bode plot with external waveform generator - Page 1
Forum section: electronics / testgear

author: ptluis
author_rank: Frequent Contributor
timestamp: March 13, 2025, 04:46:04 pm
content: Is it possible to bode plot on this scope using an external AWG ?For example Siglent SDG2122X?Will DHO914S be able to bode plot at frequencies around 100MHz? Obviously not with the internal awg, but with an external one?Thank you

author: TheoB
author_rank: Regular Contributor
timestamp: March 13, 2025, 10:33:33 pm
content: Have a look herehttps://github.com/tband/dho-remoteThat will work at any frequency but 100MHz seems a bit high for Bode plots using 1M interfaces. You quickly get some phase rotation due to difference between two channels. A calibration is probably needed.This is more the domain of a vector network analyzer (50 Ohm based ports). Nowadays they are very affordable like the LiteVNA 64.

author: ptluis
author_rank: Frequent Contributor
timestamp: March 14, 2025, 12:15:46 am
content: Quote from: TheoB on March 13, 2025, 10:33:33 pmThanks for the link, it looks a nice tool but I don't have an dho series scope, I'm still deciding what could be the best option for my needs at the moment.Concerning the 100MHz frequency I'm trying to build some bandpass filters and have been using fft to get a close to real viewable "graphic" of the frequency response. I though on buying an all in one solution like the MSO5074 but the AWG only goes to 25MHz and since I have access to a Siglent SDG2122X I thought it would be nice if it works with this small new scopes.I'm also looking at the tinySa ultra but seems there are multiple versions and from what I understand they are related to max sweep frequency capability.

author: thm_w
author_rank: Super Contributor
timestamp: March 14, 2025, 12:31:13 am
content: So step back, what is the purpose of the bode plot?DHO900 is a dumb thing to buy, if you want to buy DHO800 and an external gen, or siglent with matching gen.As long as you have two devices that can be controlled with Python, any devices can be used.tinySA ultra is explained here:https://www.eevblog.com/forum/testgear/tinysa-ultra-launched/msg5775969/#msg5775969The 407 has better noise floor, upper frequency is higher, but I don't think those would matter to most people on a smaller budget. Cost is a lot more.

author: Fungus
author_rank: Super Contributor
timestamp: March 14, 2025, 02:19:19 am
content: Maybe there's a way to do it, maybe there isn't, but DHO914S has no advantage over DHO804 in this situation and costs a lot more

author: 2N3055
author_rank: Super Contributor
timestamp: March 14, 2025, 07:42:56 am
content: DHO900 is a weird device with all kinds of weird compromises and caveats.If you already have Siglent SDG2122X just buy SDS804xHD and have ready made top class Bode plot out of the box.For the money difference, you can buy an external logic analyser and one of small VNA devices and have a complete lab that will give you lots of capability.

author: ptluis
author_rank: Frequent Contributor
timestamp: March 14, 2025, 12:20:41 pm
content: Quote from: thm_w on March 14, 2025, 12:31:13 amRight now for low, high and bandpass filters, and some power supply feedback loops analysis. I don't have a fixed field of work, now is this in a month from now could be something else, that's why I'm looking for an all in one solution, at least with the most features possible available, and with the capability to be connected to batteries meaning portable. I sold most of my bench lab equipment because I'm converting to portable/mobile equipment, there's not much offer in this field (mobile) with many features available. I've been renting equipments because i was constantly buying/swapping/selling. And now it's time to buy something more all in one if you know what I mean.

author: ptluis
author_rank: Frequent Contributor
timestamp: March 14, 2025, 12:27:14 pm
content: Quote from: 2N3055 on March 14, 2025, 07:42:56 amEverything is considered but the major problem is that I also need the equipment to allow being powered by batteries, like these dho8xxx or 900 series. The SDG2122X is rented, can't find a 100MHz AWG battery powered, I've seen rigol has some new SG900 pro but honestly haven't had the time to read more about it.

author: 2N3055
author_rank: Super Contributor
timestamp: March 14, 2025, 01:15:35 pm
content: Quote from: ptluis on March 14, 2025, 12:27:14 pmThat is tough call. If it has to be Rigol, then go with DHO800. That one at least is very inexpensive and has basic sampling done right.Good luck.

author: ptluis
author_rank: Frequent Contributor
timestamp: March 14, 2025, 03:44:15 pm
content: Quote from: 2N3055 on March 14, 2025, 01:15:35 pmI've been using Siglent and GW-Instek equipments for the last couple of years, I still own some, but Rigol will be my first time if i decided for that.

author: TheoB
author_rank: Regular Contributor
timestamp: March 14, 2025, 05:09:58 pm
content: I have both the LiteVNA64 and the tinySA Ultra. Although the SA also has a frequency generator it does not work as tracking generator (it's spectrum analyze OR signal generator). So for filter analysis go for a (battery powered) VNA. The NanoVNA might be a cheaper option (50$) depending on the frequency range you want to cover.The DHO series can be battery powered but they do need a lot of power (35W), so it will not last long. On the other hand, it is possible to run from a batteryIf battery operation is an important factor you could consider a more portable solution (HDS272S for instance?)With the DHO804 you get a lot of bang for bucks as it can be upgraded easily to the the DHO914 with all the options. The signal generator and Bode option is missing, but that is said to be of low quality. Go for Siglent.

author: hfleming
author_rank: Regular Contributor
timestamp: March 14, 2025, 05:23:49 pm
content: Battery powered? Do you mean USB-C? What is wrong with just taking a UPS or battery+inverter along with mains-powered equipment in the field?

author: ptluis
author_rank: Frequent Contributor
timestamp: March 14, 2025, 08:02:05 pm
content: Quote from: TheoB on March 14, 2025, 05:09:58 pmMy option here is to build a 12V custom battery pack. From what I've been reading the first PS supplied with the dho800 had a fixed voltage without any PD negotiation so it shouldn't be a problem.Concerning battery+ inverter that's what I've been using its ok for some situations not so good for others due to noise introduced by the inverter. Not forgetting the dimensions and weight of these units.Regarding spectrum analyzer I'm choosing tinySA ultra because I want to analyze wifi networks at 2.4GHz, 5GHz and 6GHz