| Products > Test Equipment |
| buy a better oscilloscope than the Siglent SDS1104X-E |
| << < (11/19) > >> |
| BillyO:
--- Quote from: 2N3055 on August 15, 2023, 08:26:50 am ---For instance I will take simpler device, that is reliable and works well, over a device that was developed by marketing department and has impressive list of "features" in datasheet but none of it works as it should... --- End quote --- You mean like these: http://hantek.com/products/detail/17182 And these: http://www.fnirsi.com.cn/product/704340100322037760 :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD :-DD |
| Performa01:
… so in my last posting I've shown the absolute worst case – and was curious if someone would jump at it. That's not happened, so here I'll show a more realistic use case. In my last posting, I've used 1 meg input impedance and left the input open, which would be equivalent to a x10 probe at low frequencies. In any real power supply noise measurement we would either use a direct coax connection (total input impedance <50 ohms) or a x1 probe (total input impedance is a couple hundred ohms) – especially when looking for very low noise levels like 600 µV. While the termination doesn't make a significant difference at higher frequencies when it comes to noise, it is still important at low frequencies. This time I use 50 ohms input impedance (the result would be the same if we choose 1 meg input impedance and use an external termination up to a few kiloohms). Furthermore, there's no need to worry about aliasing, even when we lower the FFT-sample rate a bit. If the noise from the PS has high frequency content, then we need a wide FFT bandwidth hence also a high FFT sample rate anyway. If it's really just low frequency noise, then a low sample rate is sufficient. Aliasing would only fold down the scopes own noise, thus rising the intrinsic noise level of the measurement, but because of the strong 1/f characteristic it absolutely doesn't matter if a higher frequency part with <5 nV/√Hz gets added to the measurement. Consequently, I've now chosen 10 ms/div horizontal time base for a lower frequency limit of 10 Hz and a FFT sample rate of just 25 MSa/s. SDS2354X Plus_Noise_50_10ms_20kHz_10bit As we've seen before, 600 µVpp would be equivalent to 212 µVrms or -60,46 dBm and the OP could analyze noise and spurs in his scenario as long as the FFT plot does not exceed that level. As we can see from the attached graph, even at just 100 Hz, the measured level is still -91 dBm (this time for 45 Hz bandwidth), that leaves plenty headroom for analyzing a -60.46 dBm signal. |
| Fungus:
--- Quote from: Martin72 on August 15, 2023, 09:25:57 pm --- --- Quote ---Look again, it's much more than "touch screen bolted onto legacy interface". --- End quote --- If you only watch videos and pictures, you might not get the right impression. In reality, the creation and positioning of the windows was a difficult, annoying and not always as functional as intended matter. --- End quote --- But it was there, it could do it. You could have a 3D view alongside a normal view. --- Quote from: Martin72 on August 15, 2023, 09:25:57 pm ---This ultimately drove me into the arms of siglent. What they offer is not super fancy, but it works as intended. --- End quote --- You'd have a point if they were both the same price, but they aren't. If price isn't an issue, if you simply want the "best" then why stop at Siglent? R&S make some very nice devices. --- Quote from: Veteran68 on August 15, 2023, 11:21:16 pm ---Thanks to sub-$500 oscilloscopes, now any semi-serious hobbyist or maker can afford a scope. Since those people are likely a majority of this forum, I'd say $3000 for a scope (while certainly cheap for commercial use) is still WAY out of reach of most of them. I certainly won't pay that for my personal use. --- End quote --- Yep. For the stated task, ie. measuring noise on a power supply, the Rigol HDO is perfectly capable. |
| Fungus:
--- Quote from: Veteran68 on August 15, 2023, 11:21:16 pm ---What mood is that, exactly? --- End quote --- The mood I usually see is a "BMW owners club" mood. BMW owners justify spending more on their cars by going on and on about how fast they are and how they handle in the corners, how every other brand is somehow "compromised", etc. It all makes sense on paper but the simple fact is that most people just want to get around the place at normal speeds and carry shopping twice a week. A Ford Fiesta can do that perfectly and isn't missing any basic features like aircon or wheels. Don't believe me? Siglent owners give the exact same excuses for not owning an R&S as BMW 3-series owners give for not owning a 5-series or 7-series. Maybe when somebody asks "what 'scope should I buy?" we should start out by asking them what car they drive and answer accordingly. I predict these threads will be a lot shorter if we do that. --- Quote from: Veteran68 on August 15, 2023, 11:21:16 pm ---Thanks to sub-$500 oscilloscopes, now any semi-serious hobbyist or maker can afford a scope. Since those people are likely a majority of this forum, I'd say $3000 for a scope (while certainly cheap for commercial use) is still WAY out of reach of most of them. I certainly won't pay that for my personal use. --- End quote --- Yep. |
| Performa01:
--- Quote from: Fungus on August 16, 2023, 06:05:48 am ---If price isn't an issue, if you simply want the "best" then why stop at Siglent? R&S make some very nice devices. --- End quote --- Oh yes ... "the best". You sure have massive experience with R&S scopes. It would be very interesting how you manage to do the measurements I've shown above with just 128kpts FFT length? As always, I miss the demonstration and measurement results to back up your claims... --- Quote from: Fungus on August 16, 2023, 06:05:48 am ---Yep. For the stated task, ie. measuring noise on a power supply, the Rigol HDO is perfectly capable. --- End quote --- Here also ... have you ever tested one? If so, why not show us the results, so everyone can see this "perfect capability" with their own eyes? I do not doubt that it can do it, but seeing is believing... |
| Navigation |
| Message Index |
| Next page |
| Previous page |