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Projects, Designs, and Technical Stuff / Re: more modern version of tl494?
« Last post by xavier60 on Yesterday at 11:59:37 pm »
I have a strong preference for the UC3525.
It is reassuring to see in the internal block diagram, the steering flip-flop being clocked directly by the oscillator and also the latch at the comparator's output.
Not so for the TL598 despite the claims. The extra opamp might seem useful but can be difficult to achieve fast current limiting with it.
With the UC3525, I implement fast pulse-by-pulse limiting by pulling down the soft-start pin.
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Beginners / Re: Question about use of Differential using scope USB port
« Last post by David Hess on Yesterday at 11:41:03 pm »
A differential probe *must* be grounded to the oscilloscope to control its common mode input voltage.  If it was isolated, then its common mode voltage could drift out of range and present a safety hazard itself.  So the connection to the USB port is not a concern because the probe will be grounded through the BNC connection anyway.

Manufacturers who make oscilloscopes that have galvanically isolated inputs warn about using differential probes with them unless they can be separately grounded to the oscilloscope.
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No, because I order from Digikey/Mouser/Farnell.
When there are so many cases of wrong cross sections, i would be very curious not caring about big names.

I've never measured explicitly, but if you told me you bought genuine belden wire from and authorized distributor and it was smaller than what it says on the box I'd be surprised and I would go measure some of the wires in my shop.  The fact that 5 different wires purchased from random resellers on Amazon or eBay were counterfeit it doesn't surprise me at all.
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Test Equipment / Re: Troubles with HP-8903B
« Last post by Tony_G on Yesterday at 11:37:26 pm »
Great response SRB - Way more useful than my quick, "here is what my working one looks like" post.

Look forward to the results here.

TonyG
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Test Equipment / Re: Siglent SSA 3021X... Ooops
« Last post by tautech on Yesterday at 11:35:37 pm »
Have you considered working through some of the performance verification steps in the service manual ?
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Test Equipment / Re: SDS800X HD Wanted Features
« Last post by KungFuJosh on Yesterday at 11:28:49 pm »
Any advanced user with some active Math channels.
A few more words would have been useful, and would have sounded much nicer...

From the guy who always tells me he prefers short answers to long winded ones. 😉😉
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GCC can do static stack usage analysis. Just add "-fstack-usage" to the build flags, then GCC spits BINARY.su file with data.
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Well, conflating "non-visible" with "dark" was a case of ostrich policy.

"There is no dark side of the moon really. Matter of fact it's all dark."
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There is also Smoothieware for LPC17xx (ARM Cortex-M3) licensed under GPL v3.
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Test Equipment / Re: Choosing between entry-level 12-bit DSOs
« Last post by KungFuJosh on Yesterday 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 party 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, support, 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
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