Wow! $123 Hanmatek DOS1102 initial comments

[rhb]

Amazon was offering these recently for $123 discounted from $169.  I didn't need it, but bought one because it was cheap.  I'm stunned!! Most sellers ask well over $200 which is too much relative to the competition.  But at $160-170 it's a no brainer for a first scope.  I was able to use it without reference to the manual except for how to save a screen dump.

This is an very good basic 100 MHz DSO.  Risetime is 2.8 ns which corresponds to 125 MHz, but it's at the cost of 16% overshoot.  In other words, the filter slope is too steep.  An external 100 MHz LPF would provide Tek quality overshoot.

Notably it runs on 5 V and there is a lot of room inside for a LiPo pack, so I plan to hack it for battery power. 

I had the display in dot mode when I saved the screen shot and persistence was off. Source is one of Leo's 40 ps pulsers.

Edit:  Added additional screen shots of various things.  Very impressed with the FFT.

Have Fun!
Reg

[BillyO]

The more interesting option is the DOS1104 for $170.

But the real question is what is the support for these?  You really haven't put it through the mill here.  Are there bugs?  Will they ever get fixed?  Where are the service centers?  What are the triggering options like?  Will it decode serial streams?  What options can I add on later?

These are in that middle ground where your spending enough money to need answers to those questions.  If someone buys a $35 scope and it's a POS, then no big deal.  But a $132 or $170?  That's 1/3 the way to getting a real scope that does come with support and serviceability.

Good examples of this middle ground are the FNIRSI "100MHz" scopes and the Hantek nightmares.  Then there is Uni-T.  They build much better stuff than FNIRSI or Hantek, but have -20% support .. even though they charge near premium prices.

I'm a full believer that having some scope is better than having no scope, but over $100 I begin to worry about how well my money has been spent.

[Kosmic]

Hanmatek  DOS1102 and DOS1104 are Owon SDS1102 and SDS1104 rebrand.

Their weak point is probably the memory. 10K for the DOS1102  and 20K for the DOS1104.

[Aldo22]

Is this scope better than the Hantek DSO2C10 in any specific aspect (features / performance)?

[rhb]

I have a Hantek handheld junk scope replaced by an Owon HDS272S which is a proper scope with limited controls.  By which I mean I can service a radio with it.

I just returned  a Tooltop ET120M.  I was expecting to return this also, but it is too good.  So unless I discover a show stopper I'm keeping it.

Trade dress looks like Owon's. It's not as feature rich as more expensive scopes, but it has what I use most and it  does the job.  I plan to add as many 18650s as will fit and make it fully portable.  The 10k depth is the only complaint.  I've got a12 bit Owon with 10 million but crappy UI.  I'll have to compare the two side by side.

The Fnirsis are  30 MHz scopes for the same money as the DOS1102.  I know nothing about the Hantek you mention.

Have Fun!
Reg

[rhb]

Here's  comparison of a Rigol DS1102E vs the Hanmatek DOS1102 showing a 1 MHz signal 100% AM modulated at 50 kHz.

Which one would you prefer?

[ebastler]

Here's  comparison of a Rigol DS1102E vs the Hanmatek DOS1102 showing a 1 MHz signal 100% AM modulated at 50 kHz.
Which one would you prefer?

Did the comparison involve time travel? 

Yeah, I know Rigol still offers the DS1102E. But why?

[Aldo22]

Which one would you prefer?

The Hantek DSO2C10 for $130. 

[rhb]

Well, That doesn't look as if it's modulated for starters.   But hey, if you like it, go for it.

But here are some more comparisons.  3928 is the spectrum analyzer mode for the Instek mixed domain version.

[rhb]

And a couple more.

I'd like to note that it's a *lot* easier to adjust the Hanmatek which quite astounds me.

So 2 Rigols, an Owon and an Instek.  The latter was well over $2k.

I should note the first photos were with a 1 MHz carrier and 50 kHz modulation.  The later ones are a 10 MHz carrier with 50kHz sidelobes.

[ebastler]

I'm not sure I understand the settings you chose for many of those screenshots. If you modulate with 50 kHz, what does an FFT with 5 or 6 MHz/div tell you? I think you want to choose a much longer record and hence finer spectral resolution to properly show the sideband peaks.

Overall it is not an ambitious test -- due to the 100% modulation depth the sidebands are very clearly seen. Only scopes which are limited to a very short FFT length, and hence poor spectral resolution, should struggle. I have attached another example for the venerable DS1054Z, with settings I would choose. (You can't see the carrier and modulation frequencies in the time domain anymore if you want a record length with decent spectral resolution.)

[rhb]

Now try it with a 10 MHz carrier.  The Hanmatek is aliased like mad.  I was quite surprised at the result.  The only way I can see it is possible when the DS1102E fails is the clock and trigger are more stable.

However, my main point was the DOS1102 really is a 100 MHz DSO under $200.  That's half of what my DS1102E cost.

My current focus is getting amy shop lighted and wired, building an 11' x 16' Faraday cage built for my lab and building a 2nd 6 bay 6' rack to hold all the stuff.  I have a 40 year history with DSP and an insane (~$1 million ca 1995) lab suite.   I plan to have some fun dissecting what the various models are doing.

Have Fun!
Reg

[ebastler]

Now try it with a 10 MHz carrier. 

That still works alright, but it's pushing the capabilities of the DS1054Z. And a lot of knob-twiddling and stabbing in the dark are involved, since it is not transparent at all how many points are actually used in which setting.

I don't mean to brag about the 1054Z; it's not a very braggable piece of kit... Just wanted to point out that the FFT test does not tell that much about the scopes' capabilities.

On a related note: Has intensity grading reached those low-end scopes yet? That would be a deciding factor for me whether I would recommend a model to a beginner. And for digital/embedded projects: Can they decode and trigger on the basic serial protocols -- RS-232, I²C and SPI?

[rhb]

Interestingly, my DS1202-ZE can't reproduce your plot.  I'm about to check for software updates.  I can't set the center frequency at 10 MSa/s above 8 kHz.

More after an update.  BTW the Hanmatek required a self-cal to produce an accurate FFT.

[ebastler]

I think I'm on the latest firmware. It identifies as 04.05 SP2 in the system info.

You are running the FFT in "memory" mode, right -- not from the trace (screen) buffer only? If I recall correctly, the scope always falls back to "trace" mode upon power-on, which is rather useless.

[rhb]

Not sure.  I haven't used the DS1202-ZE since I got it. So highly likely user error.  I'll check.  I bought it when they introduced them at $300.  I had to see.

For $300 a 24 MSa 200 MHz DSO is worth having for rare problem.  Same with my Owon XDS2102A 12 bit, 10 MSa scope.  I actually don't care if they are utter crap as a scope, I bought them for  deep one shots.  They are high speed data loggers.

Edit:

Here's a better measurement of risetime with infinite persistence.  0.35/2.48e-9 = 141 MHz.

[Aldo22]

Well, That doesn't look as if it's modulated for starters.   But hey, if you like it, go for it.

Sorry, I misunderstood (learning  ).
Is the attached screenshot what you meant?

[rhb]

Which one would you prefer?

The Hantek DSO2C10 for $130. 

This is the post I was referencing. The last 2 plots are the correct analog to what I was doing

The width of the FFT bins is 1/(n*dT).  The maximum frequency is 1/(2*dT).  The 10k buffer works because it's aliased.  As I reduce the sample rate the sidelobes spread out as T=n*dT increases.

A proper waterfall display has been on my "To Do" list for quite a while.  Time for me to grind my way through the math and replicate the Instek SA software so other OEMs can include the feature in DSOs and SDRs.

I was comparing to all the DSOs I had handy.  And a 1GHz LeCroy is probably not a fair comparison nor was it handy.  The DS1102E was my first DSO.

The Hanmatek appears to be the Owon minus the internal SMPS.  The DOS1104 has 5 mV/div instead of the 20 mV/div of the DOS1102.  I ordered a DOS1104 from Aliexpress for $206 for the sake of the greater sensitivity.

I bought a Hantek 3 in 1 which was very poor.  Replaced it with an Owon HDS272S which is a proper scope with limited controls.  I had always assumed that Hanmatek was a step down from Hantek, so I was quite surprised when I measured the risetime.

Have Fun!
Reg

[Aldo22]

The last 2 plots are the correct analog to what I was doing

Thank you!

I had always assumed that Hanmatek was a step down from Hantek, so I was quite surprised when I measured the risetime.

I compare the Hantek DSO2C10 with the Hanmatek DOS1102 because it is in a similar price range and also has 2 channels and about 100MHz bandwidth.
Here are two more screenshots from the Hantek:
Rise time measured with a Si5352 and sensitivity.

Have Fun!