New oscilloscope from Fnirsi DPOS350P

[Etrius]

This thing got on my nerves.  When I have connected the generator at 50MHz, with a probe from the oscilloscope, to its generator, x10, it shows 1.12V.  When I switch to x1 it shows 0.328V.  The generator is at 1V.

I think this is normal. The probes supplied with the DPOS350P reach up to 10MHz when set to 1X. To go beyond that, you need to set them to 10X and calibrate them.
Personally, I think that an error in measurement  is acceptable (1V -> 1.12V)

[Ivont]

This thing got on my nerves.  When I have connected the generator at 50MHz, with a probe from the oscilloscope, to its generator, x10, it shows 1.12V.  When I switch to x1 it shows 0.328V.  The generator is at 1V.

I think this is normal. The probes supplied with the DPOS350P reach up to 10MHz when set to 1X. To go beyond that, you need to set them to 10X and calibrate them.
Personally, I think that an error in measurement  is acceptable (1V -> 1.12V)

Thank you.   I won't return it.   It turned out that the error was coming from the probes, just like you said.   In the video I tested it with bnc. https://youtube.com/watch?v=LHqEyywe3LY

[Etrius]

With my DPOS350P, I detect the same waves as your video. Only the voltage values ​​have a slightly greater error than your readings. However, when displaying 50Hz on my 1013D, I detect a perfectly square wave.

[Ivont]

The probe works best at 132pf. And for the rectangular signal, 50Hz, you can see, in the video, the other oscilloscope also shows, like fnirsi.    I have two more, they show the same thing.

[Ivont]

I checked, after adjusting to 132pf, and it turned out that the signal has improved on both divisions.

[Etrius]

What do you mean you set the probe to 132pF?
I don't think it's possible to change the capacitive load with the supplied probes.

[Ivont]

I'm talking about tuning the probe trimmer.    This is the tuning capacitor.    I used an LCR meter.    I had a really big problem.    It stopped charging.

[Ivont]

This thing got on my nerves.  When I have connected the generator at 50MHz, with a probe from the oscilloscope, to its generator, x10, it shows 1.12V.  When I switch to x1 it shows 0.328V.  The generator is at 1V.

I think this is normal. The probes supplied with the DPOS350P reach up to 10MHz when set to 1X. To go beyond that, you need to set them to 10X and calibrate them.
Personally, I think that an error in measurement  is acceptable (1V -> 1.12V)

. Do you have such signal ripples.

[Ivont]

I use an oscilloscope generator. With Bnc-Bnc the ripples decrease, but are observed when the amplitude of the oscilloscope generator is reduced. With the oscilloscope open and touching the housing of the MS9714 integral with a finger, they become more visible.

[Ivont]

I am using an oscilloscope generator.    In Bnc-Bnc, curls decrease, but three decreases in amplitude are observed.    With the oscilloscope open and a finger touching the MS9714 integral, it increases.  the ripples I see superimposed on one period at 5MHz are 25.

[Etrius]

Do you have such signal ripples.

I hadn't noticed, but when I stop it, I see these ripples too. When the trigger is in AUTO I only see flickering
Thanks for pointing that out

I am using an oscilloscope generator.    In Bnc-Bnc, curls decrease, but three decreases in amplitude are observed.    With the oscilloscope open and a finger touching the MS9714 integral, it increases.  the ripples I see superimposed on one period at 5MHz are 25.

I haven't done any noise testing, and I haven't opened the oscilloscope yet. I'm curious to see what's inside, but I don't have time yet.

[Ivont]

I'm talking about tuning the probe trimmer.    This is the tuning capacitor.    I used an LCR meter.    I had a really big problem.    It stopped charging.

Today I am making a detailed video about all possible channels.  It will include all bugs and defects.  Apparently this is the right one.    This will restore the balance in nature.  They don't understand that it's not all about money.  Something is wrong with them.  They do not want to communicate and thus cut the branch they are sitting on.

[mishail71]

Let them go to hell!!! And far away!!!
FNIRSI is complete crap!!!

[Ivont]

Let them go to hell!!! And far away!!!
FNIRSI is complete crap!!!

I wanted them to refund 1/2 of the money, but they wouldn't agree.

[PlainName]

Wanting a 50% refund smacks of someone trying a fast one, and it's not surprising they wouldn't go for it. If you're really unhappy, a return for full refund is the way to show you're serious.

Having said that, just last week I got a 50% refund on something I was unhappy with. But in that case I'd originally asked for a full refund and license revocation, and they talked me into accepting a 50% refund and keep the license. Had I led with a request for that same 50% it would have gone nowhere.

[Ivont]

Fnirsi replied that there is still work on the new firmware and it will be released on the official site. "We are still optimizing the firmware for the DPOS350P".

[Evi]

Did not use for device some time. Today I noticed that battery does not charging.
Anybody know how the charging system consrtucted?

....
Stupid! I forget about 12V for charge.

[Ivont]

I'm talking about tuning the probe trimmer.    This is the tuning capacitor.    I used an LCR meter.    I had a really big problem.    It stopped charging.

Read the entire comment.

[KiethWallace]

You must use the original charger.

[Ivont]

You must use the original charger.

I used the original charger.  It's with the oscilloscope.  I have not used any other because I have none and no other should be used.

[KiethWallace]

Is there any way to do a proper frequency calibration? I see no built in method and cant find anything online. I know I can come up with a hardware solution, but I shouldn't have to do that.

Problem: Generate 10Mhz with this scopes DDS generator and then look at it with a calibrated frequency counter. Mine is almost 3000hz off. Up the frequency to 20Mhz and I find the generated signal off by double. Bump it up to 50mhz, well...you will see.

This doesn't just effect the generator - it makes it impossible to trust the frequency of the spectrum, and - you probably guessed it - the timing is actually hosed on the scope as well.

Obviously I am suspecting the base crystal is not calibrated from the factory. With this is mind, I am betting I am not alone in the frequency being off. So much for that amazon ad saying +/- 1hz accuracy. Unfortunately there is no use case that I have for such an inaccurate device.

Maybe I need to forget this and just return it to amazon as defective?

Im curious as to how far off other peoples units are?


I am certainly open to being wrong about the only option being a hardware fix, if someone can tell me how to adjust the base crystal frequency through some hidden service menu or something.

Anyone?

[KiethWallace]

[/quote]I used the original charger.  It's with the oscilloscope.  I have not used any other because I have none and no other should be used.
[/quote]

Perhaps you have a failed battery?

Regards

[Ivont]

I used the original charger.  It's with the oscilloscope.  I have not used any other because I have none and no other should be used.
[/quote]

Perhaps you have a failed battery?

Regards
[/quote]I replaced the damaged resistor and now it works.  It lasts for 2 hours.

[Ivont]

About the frequency, I can't help you.  Changed the probe, but barely.

[Grandchuck]

Is there any way to do a proper frequency calibration? I see no built in method and cant find anything online. I know I can come up with a hardware solution, but I shouldn't have to do that.

Problem: Generate 10Mhz with this scopes DDS generator and then look at it with a calibrated frequency counter. Mine is almost 3000hz off. Up the frequency to 20Mhz and I find the generated signal off by double. Bump it up to 50mhz, well...you will see.

This doesn't just effect the generator - it makes it impossible to trust the frequency of the spectrum, and - you probably guessed it - the timing is actually hosed on the scope as well.

Obviously I am suspecting the base crystal is not calibrated from the factory. With this is mind, I am betting I am not alone in the frequency being off. So much for that amazon ad saying +/- 1hz accuracy. Unfortunately there is no use case that I have for such an inaccurate device.

Maybe I need to forget this and just return it to amazon as defective?

Im curious as to how far off other peoples units are?


I am certainly open to being wrong about the only option being a hardware fix, if someone can tell me how to adjust the base crystal frequency through some hidden service menu or something.

Anyone?

I don't know of any way to calibrate it.  However, your unit seems off:
https://www.eevblog.com/forum/testgear/new-oscilloscope-from-fnirsi-dpos350p/msg6118553/?topicseen#msg6118553