New (toy?) DSO+LCR meter - Fnirsi DSO-TC2 (june 2022)

[KungFuJosh]

No, this figure shows the weather on Mars or something similar

The weather is only 0.11 ohm on Mars?? No wonder them billionaires can't resist going there.

I also have some sympathy for this little device because it looks cute, but if we're honest, it's not really good at anything.
Max 100kHz? A $3.90 DIY SG can do 1 MHz with adjustable amplitude.

A $62 DSO1511G has a 2MHz Signal Generator.

Range doesn't make a thing good or bad. The question is what is it good for. I test audio equipment, and that's almost always a 1K sine wave. So it would be perfectly acceptable for that. I don't expect it to compare with my SDG2122X, and I don't expect the scope to compare with my Siglent scope either. But as toys go for $50, it's pretty cool.

I'd say it's okay at a few things. The AWG is okay for the range I actually need. I'll probably almost never use it for that anyway. The DSO is okay for basic uses or screwing around, also won't likely use it much. I mostly bought the thing because I like the transistor tester, which appears to be at least as good or better than the TC1. The rest is just extra fun stuff.

Two things I like better about the TC3 than the TC1: 1. nicer screen, 2. last test persists on the screen instead of the device shutting itself off. That's useful if you need to record data for comparison.

My curiosity will make me try the TC3's DSO when I find something with a parasitic oscillation, just to see how it performs on something useful. Maybe won't even be able to see the PO based on the frequency range, but that won't make trying less fun. 😉

[Aldo22]

@KungFuJosh

If it helps you, then good for you.
If you have better equipment and it's just a toy for you, then good for you.

I just don't think that $50 for the TC3 is a very good investment for someone who wants cheap basic equipment, because in the end it just doesn't do enough for that money.
I wouldn't recommend it to anyone who wants basic equipment for less than $100.

Of course, it's not so expensive that you would seriously regret buying it, but there are better devices out there for just a little more money.
And honestly, I find the worst thing about the TC2/TC3 is not even the very limited bandwidth but the almost-1-button operation of the oscilloscope drives me nuts. 

[KungFuJosh]

Of course, it's not so expensive that you would seriously regret buying it, but there are better devices out there for just a little more money.
And honestly, I find the worst thing about the TC2/TC3 is not even the very limited bandwidth but the almost-1-button operation of the oscilloscope drives me nuts. 

Yeah, it's pretty goofy to operate in scope mode. It's also a little disappointing that you can't control (or I haven't bother to figure out how to control) the signal generator while using the scope mode. In scope mode it just puts out the square wave to calibrate probes.

I think it's hard to recommend many products under $100 that do most of the features. I'd say the TC1 is a much better investment for transistor testing. There are lots of similar signal generators in that price range. But I've never seen a scope I thought was really useful for less than at last $250, but personally nothing I like under $500.

As I said, for me it's just a toy. Good for me. 😉

[Aldo22]

Hi  KungFuJosh

I think it's hard to recommend many products under $100 that do most of the features. I'd say the TC1 is a much better investment for transistor testing. There are lots of similar signal generators in that price range. But I've never seen a scope I thought was really useful for less than at last $250, but personally nothing I like under $500.

Opinions differ on what a "useful" scope is. 
But we're talking about entry level / lowest budget here.

What I can tell you with certainty is that a DSO1511G is at least a 20 times better scope than the TC2/3 in every aspect for only about $10 more.
It has dedicated buttons for time base and vertical sensitivity. That alone is a relief.

Of course, it's not a $200+ scope, and it shouldn't be compared to those, and maybe the specs are a bit "optimistic", but compared to the TC2/3 it's very usable.
Check out the video from "Adrian's Digital Basement".
He simply uses it as a tool to repair the C64. The video is fun to watch.

https://www.eevblog.com/forum/testgear/dso1511e-review/msg4507981/#msg4507981

[ober]

I'm not 100% sure, but it looks like Chinese friends ported Karl-Heinz's original code to the STM platform.

This comment was about the DSO-TC2.  The DSO-TC3 also seems to have some porting effort behind it.
The results, unfortunately, are not pretty.

Here is a "10 µF" ceramic capacitor in a TC1 and in the DSO-TC3.  Note that the TC3 hallucinates an additional pin!
(You get the same hallucination about the third pin independent of where you put the actual pins.)

Apparently the DSO-TC3 measures itself...  (And note the Rds and Cg values :-)

[indman]

Apparently the DSO-TC3 measures itself...  (And note the Rds and Cg values :-)

Dear authors Markus Reschke and Karl-Heinz Kübbeler have been developing, refining and polishing the code for years, but you want the Chinese toy to work as well as the original AVR project. This will not be in the near future, porting successfully code to another platform to take into account all the subtleties and nuances of ARM is a very difficult task.

[Aldo22]

Is it true that the DSO-TC3 no longer has the PWM output up to 10MHz?
This was one of the more useful hidden features of the DSO-TC2.

[slavoy]

TC-3 has 1-100kHz PWM output @3.3V

[Aldo22]

TC-3 has 1-100kHz PWM output @3.3V

Thanks.
The TC3 seems to have a signal generator with different waveforms.
The TC2 has PWM generators in two places:
- One in the oscilloscope context. This is only capable of PWM up to 80 kHz. It works in parallel to the oscilloscope mode.
- One in the tester menu. This one can do PWM up to 10 MHz!

I didn't notice this feature for a long time, but it's quite remarkable as an add-on function for such a toy.
It seems to have been removed from the TC3, right?

Attached is a screenshot of the PWM output at 5MHz/75% duty of the TC2.
The screenshot is of course not from the oscilloscope of the TC2, which can not display this frequency range (It's from my DSO2512G)

[slavoy]

It seems to have been removed from the TC3, right?

Yep, you get only 1kHz square for the probe compensation when in scope mode.