Recent Posts

1

Test Equipment / Re: Choosing between entry-level 12-bit DSOs

« Last post by KungFuJosh on Today at 11:24:46 pm »

There are many things that seem to point to the Siglent SDS804X HD as the obvious choice (2G sample rate; better math functions; more USB ports; fewer bugs?). However, to the extent that I have been able to follow the discussion above, at least some of the advantage of the Siglent seem to be tied to more advanced topics than I expect ever to get into. (Yes? No?)

Don't think that way. My actual use case is ridiculously simple (compared to the abilities of my scope) audio work. I usually feed a 1kHz sine wave into a piece of audio gear to trace issues (if there are any). Otherwise I will use the Bode function to get details of other audio gear. However, being on this forum, I have learned a LOT more and used significantly more functions that the scope has. People discuss things, I try it out, and if I didn't understand before, chances are now I might understand it a little better. I got the Batronix demo board and learned a lot from that too. There's always potential for more, but only to the limit of the tools you have.

Meanwhile, there are some features that the Rigol brings to the table that I find attractive, including the slimmer size, possibility of powering from a battery pack, HDMI output, easy addition of wifi capability. VESA mount might also be valuable for my limited workspace.

The only two benefits IMO to the Rigol are the VESA mount and the HDMI output. That's it. If those things are more important to you than actual measurement ability, then it's an easy decision. However, even the VESA mount can be done for Siglent with the help of 3D printing and a little creativity.

I am getting ready to read back through the extended threads that detail performance, bugs, desired features, etc. for each of the units, but in the meantime, I have three specific questions:

The last feature I noted for the Rigol leads to the first specific question for this post: Have I understood correctly that there is no way to add wireless to the Siglent other than through the ethernet port?

Incorrect. Almost any wireless bridge adapter can be connected to any device with an ethernet port. There are some specific small wifi bridge adapters which have been tested and work great for scopes without WiFi. There's also the possibility that Siglent might add direct WiFi dongle support in the future after tautech annoys them about it enough.

Second specific question: I seem to recall reading something that suggested that the probes that come with the Rigol 804 are better (? or have a higher BW rating?) than those provided with the Siglent. Is that true, and should I care?

Might be true, depending on which model you get. However, you shouldn't care. I exclusively use 3rd part probes from Probe Master. Some people also like Testec. While the supplied probes are usually sufficient, I like what I like. 😉

Third specific question: I think I would likely want to "hack" either of these units up to 100MHz and greater memory depth. From what I am seeing, this seems to be easier for the Rigol than for the Siglent - true? (This also connects to the previous question - if I want to hack up to 100Mhz, are the probes going to make that less successful with one vs. the other?)

Opposite. It's much easier for the Siglent. Siglent can go up to 200MHz and actually has a high enough sampling rate to support that. Rigol can go to 100MHz (or 125MHz) but is severely limited by its sampling rate. Siglent also has better memory depth.

There are specific posts in this thread covering most of this, but a summary doesn't hurt.

Rigol Pros: HDMI, VESA mount, WiFi built in.

Siglent Pros: Speed, memory, sampling rate, stability, superior Bode and FFT, etc. Also amazing documentation in Performa01's demo thread for the SDS800X HD.
VESA mount and WiFi can be added to the Siglent, HDMI cannot.

For adding WiFi, personally I would probably try the GL.iNet GL-MT3000. Others have used the less expensive TP-Link N300 and the TP-Link AC750 would also be an option.

Thanks,
Josh

2

General Technical Chat / Re: Questions about Adelaide Australia

« Last post by SmallCog on Today at 11:22:26 pm »

I've been pondering things for you to do, we don't really have a science and technology museum here, despite being quite a technical city.

We have Codan making radios, Redarc doing DC power equipment, and many other global defense brands present doing all sorts of stuff that would be interesting if we could actually hear about it.

There is however a temporary museum display happening of radio equipment, much of it brands that were manufactured here in Adelaide.

https://www.eventbrite.com.au/e/history-festival-exhibit-of-vintage-radios-more-bookings-not-required-tickets-878560236317

This display moves around, I'm not sure when you're visiting but hopefully it will be available somewhere to view when you're here.

Definitely put aside a day to explore the various institutions along North Terrace in the city. Well worth having a look at our museum, art gallery, and state library, all of which are free to enter.



https://guides.slsa.sa.gov.au/c.php?g=410288&p=2795746

If you like good food and wine then you're in the place for that, Adelaide Hills, Barossa Valley, McLaren Vale are all within an hour of the city center and have world class offerings.

3

Test Equipment / Re: Siglent SSA 3021X... Ooops

« Last post by Joel_l on Today at 11:17:54 pm »

Except that when using the antenna analyzer, I made no changes to any SA setting.

As far as what the SA is reading, thinking about it, it's all good. The SA knows what the attenuation is set to, so can always display the power being applied to the input port.

I did test my external attenuator and it is indeed bad.

The only potential issue left is why when using the antenna analyzer did I initially get several high SWR readings, when I tried the Smith chart I got the overload warning, then things worked fine. I did not change any SA settings during these tests with the antenna analyzer.

The SA still acts odd sometimes, so I think I will still replace those switches.

4

Projects, Designs, and Technical Stuff / Re: Accurate sine wave in terms of amplitude

« Last post by Majorassburn on Today at 11:17:46 pm »

What could be a proved single opamp for a wien oscillator?

Anything with sufficient frequency response, and output voltage swing, and drive capability.

Since you still haven't bothered to tell us those parameters, how do you expect us to help you?

In addition, ponder the second paragraph here.

More thread-choking negativity and useless crap from tggzzz. 
He's a real thread-killer if I ever saw one!

Your question about op amps?  I use T.I. OP07's with excellent results in my low frequency sine wave oscillators.
Data Sheet link: https://www.ti.com/lit/ds/symlink/op07c.pdf?ts=1714331934514&ref_url=https%253A%252F%252Fwww.google.com%252F

Also, check out the numerous TI App Notes for oscillator designs with sample circuitry you might use as starting points. Best Regards.

5

General Technical Chat / Re: Russia and China to Build a Nuclear Plant on the Moon.

« Last post by soldar on Today at 11:17:08 pm »

Which was what I meant to convey, but stuffed it up.
I was thinking about how the moon presents the same side to us, & that there was always some part of the moon lit by the sun.
I neglected the fact that we don't see all of the same side, all of the time.

The far side of the moon or the occult side of the moon, as opposed to the near side of the moon or the visible side of the moon.

6

RF, Microwave, Ham Radio / Re: fake MPF102s from AliExpress

« Last post by G0HZU on Today at 11:13:12 pm »

Farnell still have stock of the BF256B JFET in the TO-92 plastic package. The price here in the UK is £0.40 each but Farnell sell them for less than $0.20 each in the US.
This is a process 50 JFET like the MPF102 but made to a tighter tolerance for Idss.

7

Power/Renewable Energy/EV's / Re: DIY Battery Bank from Recycled 18650

« Last post by FinOminal on Today at 11:12:12 pm »

more pics from their add on facebook

8

Projects, Designs, and Technical Stuff / Re: Passing 2 wires into a hot water cylinder

« Last post by ejeffrey on Today at 11:07:29 pm »

Thermowells have a number of big advantages that make them the overwhelming choice.  They precent the hot liquid from attacking the sensor, wires or insulation.  They prevent the sensor from contaminating the liquid (important if it's food!) and avoid nooks and crannies that can trap liquid and make it difficult to clean.  It's much easier  to remove and replace broken sensors or just take them out to calibrate. There are enough advantages that it's the most common way to do this and thus the easiest.

If you really need a feed through, swagelock fittings can be used for this.  Just use a solid rod the right diameter for the ferrule and connect to it on both sides.

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Projects, Designs, and Technical Stuff / Re: Linear acceleration of stepper motor

« Last post by moffy on Today at 11:03:10 pm »

Just an FYI for Andre, there is a project that might suit called GRBL: https://github.com/grbl/grbl
which runs on an Arduino, it takes GCode commands and controls the stepper motors, it is used quite extensively and would probably suit your application.

10

Power/Renewable Energy/EV's / DIY Battery Bank from Recycled 18650

« Last post by FinOminal on Today at 11:00:24 pm »

Someone on facebook is selling these:

I attempted to let the seller know this is a dangerous build, but they don't seem to care.

I thought it would be worth while getting opinions (technical and rational) from the community so they can see that it's not just me being annoying.

What are your thoughts on using random batteries that are soldered together in this way?