New toy(?) scope Fnirsi DPOX180H, claimed 180MHz/500MSps (May 2023)

[BillyO]

Подскажите какая микросхема отвечает за смещение для калибровки.Появилось остаточное напряжение на индикаторах.Что то вышло из строя.Штатная калибровка не помогает.Всё остальное работает.Или можно уже выкинуть осциллограф?Снимок без щупа.

This is an English language site.  If you want more eyes on your question you can easily use a translator to pose it.  See below...

Tell me which microcircuit is responsible for the offset for calibration. Residual voltage has appeared on the indicators. Something has gone wrong. Standard calibration does not help. Everything else works. Or can I throw out the oscilloscope? A picture without a probe.

BTW, the offset in that TINY image you posted looks minimal.  Personally, on an ultra cheap scope like this I would not worry about it.

[Kon]

В испытаниях использовались ПЧ DELTA VFD-E на 24 ампера и вентилятор 11KW 22 ампера.На снимках видно частота модулированного напряжения определяется только при сжатии сигнала,если растянуть сигнал частота определяется скорее с несущей частоты.На первых двух снимках используется автоматическая синхронизация(AUTO),на остальных обычная(NORMAL).

[Kon]

пока не могу выложить снимки ограничение по объёму

[Aldo22]

пока не могу выложить снимки ограничение по объёму

Пожалуйста, пишите сообщения на английском языке.
Это англоязычный форум.
Я тоже не очень хорошо знаю английский, но не все могут писать на своем родном языке.
---------------
Please post in English.
This is an English speaking forum.
I don't know English well either, but not everyone can post in their native language.

[Kon]

Снимки.Если нужны снимки импульсов несущей частоты напишите опубликую.

[Kon]

Это снимки с DSO2512 который тоже участвовал в этих испытаниях и синхронизирован только в авто(AUTO).Первые полярные снимки измерены относительно - и + постоянного напряжения VFD-E

[Kon]

Продолжение

[Kon]

Похоже dso2512 на низких частотах работает лучше DPOX180H.

[Kon]

схема от dso2512 может поможет разобраться с ёмкостью входа. удачи.

[jbenam]

Hello everyone, just signed up after lurking for a few years. I have been wanting to purchase an oscilloscope for years but I can’t justify spending more than a hundred bucks for what’s pretty much an hobby.

I like repairing old computers (and maybe CRTs?) and I don’t think I will ever have to go higher than 100MHz.

If so is this oscilloscope a good suggestion for retro repairs or is there something better suited?

Thanks for your help!

[tunk]

Zeeweii has two similar models with somewhat lower specs, the DSO2512G and DSO3D12. Both are cheaper.

Edit: Both has threads on this forum.

[jbenam]

Zeeweii has two similar models with somewhat lower specs, the DSO2512G and DSO3D12. Both are cheaper.

Edit: Both has threads on this forum.

Thank you for your suggestions.

Not sure if it’s my country or anything but from here both cost the same as a DPOX180H from Banggood.

From what I can understand the DPOX180H looks like the better choice?

If so I don’t mind waiting a few weeks for a superior product, unless there are better alternatives for ~120EUR? (I have already tried searching the forum but didn’t find much)

Thanks!

[Aldo22]

Not sure if it’s my country or anything but from here both cost the same as a DPOX180H from Banggood.

ZEEWEII Official Store is here: https://www.aliexpress.com/item/1005003085753955.html


At the moment (next 20 hours):

Totale parziale
95,99€
Salvato
- 10,00€
Totale
85,99€
Prezzo IVA inclusa, Spedizione gratuita

[RAPo]

Be carefull with high voltage CRT's. If you really want to that be sure the whole setup (DUT,scope and probes) is safe.
If you want to see AV-signals (coming from a computer to a display) I advise you to buy a scope with a so called video trigger.
Neither the DPOX or the Zeewei have that trigger type.
Two channel at least 50MHz  is the starting point I think.

Hello everyone, just signed up after lurking for a few years. I have been wanting to purchase an oscilloscope for years but I can’t justify spending more than a hundred bucks for what’s pretty much an hobby.

I like repairing old computers (and maybe CRTs?) and I don’t think I will ever have to go higher than 100MHz.

If so is this oscilloscope a good suggestion for retro repairs or is there something better suited?

Thanks for your help!

[jbenam]

It says 91.30EUR here. Not sure what it is going on with AliExpress’ pricing algorithm.

Anyway while 90EUR is better than 120EUR, my budget can reach 120EUR. If the FNIRSI is a better unit when it comes to build quality, support and features I will gladly spend 40EURs more.

100MHz might be necessary for some Pentium 1 boards, though? Most of the time I will work with sub-50Mhz boards.

Sorry if I am asking a lot of questions but I have put off getting an oscilloscope for 4-5 years because I keep thinking that I shouldn’t be posting such inane questions on a forum like Eevblog, but I am sure that no one better than you guys can advise me with the right purchase

ZEEWEII Official Store is here: https://www.aliexpress.com/item/1005003085753955.html


At the moment (next 20 hours):

Totale parziale
95,99€
Salvato
- 10,00€
Totale
85,99€
Prezzo IVA inclusa, Spedizione gratuita

Ehh, too much trouble for something I wouldn’t touch that much (not a big fan of high voltage). I don’t want to spend more than this and at this point I guess that video triggers don’t come on cheap oscilloscopes.

Be carefull with high voltage CRT's. If you really want to that be sure the whole setup (DUT,scope and probes) is safe.
If you want to see AV-signals (coming from a computer to a display) I advise you to buy a scope with a so called video trigger.
Neither the DPOX or the Zeewei have that trigger type.
Two channel at least 50MHz  is the starting point I think.

[RAPo]

This a very helpful forum. Ask questions like you want. The people that will respond are questions also (like the million dollar question:why and wherefore is the scope needed?) This process is maybe a bit confronting but it really helps for you descion.

[Aldo22]

It says 91.30EUR here. Not sure what it is going on with AliExpress’ pricing algorithm.

Strange. Is that with or without "2€ di sconto ogni 15€ (max 10€)"?
You will see the final price when you add it to the cart.

If the FNIRSI is a better unit when it comes to build quality, support and features I will gladly spend 40EURs more.

It's probably not that simple.
Both have advantages and disadvantages.
The DSO2512 has a video output so you can view the signal on a larger screen and also view/save it on your computer via an adapter.

The Fnirsi DPOX has better specs, but on the Zeeweii DSO2512 the software is quite mature and the device actually hardly causes any annoyance.
I don't have a Fnirsi DPOX. There are people here who have both devices.
Maybe they can give you some more advice.

In any case, the DSO2512 is cheaper than the DPOX.

[Rooster Cogburn]

Hello everyone, just signed up after lurking for a few years. I have been wanting to purchase an oscilloscope for years but I can’t justify spending more than a hundred bucks for what’s pretty much an hobby.

I like repairing old computers (and maybe CRTs?) and I don’t think I will ever have to go higher than 100MHz.

If so is this oscilloscope a good suggestion for retro repairs or is there something better suited?

Thanks for your help!

I mostly modify / repair old electronics, including my CRT collection. That's why I bought this scope. I'm quite happy with it, but I think the software features are a bit sparse. The trigger and measurement / cursor features are rather basic. I would've considered buying a more expensive bench scope, but space is at a premium so something DMM sized is a real win. I'm quite happy with my purchase, doesn't seem like you can do much better at this size and price point.

[battlecoder]

I performed some measurements and i think that this is AC blocking capacitor:


At the input (just at the output of the relay) of this capacitor signal is the same, no matter if it

This is really good info. I noticed the calibration discrepancy but I thought I was using the wrong probes (or worst; that I never calibrated them despite remembering that I did), as I used the scope on DC one day (and calibrated it), and AC at least a day later (and it looked all messed up). First, I'm glad to know it's a known problem and it's between AC and DC (which I have verified), and second, because if it's just a matter of changing that capacitor I might be able to repair it myself. I'm assuming there should be one for CH1 and one for CH2?
Also, What would be a good capacitor value to put there, though?

[Serhii74]

Dear friend!
The problem with underestimation of signal level measurements and distortion of the square wave shape at frequencies up to 1 kHz in AC mode has been resolved.
It lies in the incorrect installation of the coupling capacitor. It is set to 740 pF, but should be 0.1 mF.
After replacing the capacitors, any signal shapes and amplitudes are not distorted.
You will need to replace the circled capacitors with ceramic capacitors of the same size 0.1 microfarad 100 volts.
Testing was carried out in the frequency range from several hertz to 20 megahertz.
Distortions in the level and shape of the signals have disappeared.
The result is in photos 4 and 5.
Photo 4 shows a square wave at a frequency of 50 hertz in AC mode with a phase shift of 180 degrees.
Photo 5 measures the shape and amplitude of the voltage in the socket in RMS mode and compares it with a multimeter.

[battlecoder]

Dear friend!
The problem with underestimation of signal level measurements and distortion of the square wave shape at frequencies up to 1 kHz in AC mode has been resolved.
It lies in the incorrect installation of the coupling capacitor. It is set to 740 pF, but should be 0.1 mF.
After replacing the capacitors, any signal shapes and amplitudes are not distorted.
You will need to replace the circled capacitors with ceramic capacitors of the same size 0.1 microfarad 100 volts.

Thanks for posting here. What's the footprint? Is that a 0805 cap?

[Serhii74]

0805 or 1206

[indman]

Photo 5 measures the shape and amplitude of the voltage in the socket in RMS mode and compares it with a multimeter.

I don’t see your photo 5?

[Rooster Cogburn]

It lies in the incorrect installation of the coupling capacitor. It is set to 740 pF, but should be 0.1 mF.
After replacing the capacitors, any signal shapes and amplitudes are not distorted.
You will need to replace the circled capacitors with ceramic capacitors of the same size 0.1 microfarad 100 volts.

So is it "0.1 mF" (100uF) or "0.1 microfarad" (100nF)?

[Serhii74]

I don't know why photo 5 didn't load
I repeat the download.