Concerning the dual channel bandwidth test, it is not just the frequency counters that are incorrect above 50MHz input. Look at time 11:31. The inputs are 100MHz but the waveforms' periods are 4 divisions. Each division is 10ns. That means the waveforms are being displayed as 25MHz sine waves. This is all the classic symptoms of aliasing caused by the sampling rate being too low for the signal being investigated. There is only one A to D converter which is shared between the two channels when both are in use. That halves the sampling rate for each channel. It also explains why there is a phase difference between the two displayed channels. They are being sampled at different times but displayed as if they were sampled simultaneously. The ADC is sampling at 250MHz. In two channel operation each channel is being sampled at 125MHz. The Nyquist rate is therefore 62.5MHz. Any input frequency above 62.5MHz will be aliased and folded back around 62.5MHz. Input 75MHz which is 12.5MHz above 62.5MHz and it will be alised to 12.5MHz below 62.5MHz which is 50 MHz. Input 100MHz which is 37.5MHz above 62.5MHz and it is alised to 62.5MHz minus 37.5MHz which is 25MHz. As further proof try input of say 80MHz. I predict that it will be displayed as 62.5 - (80-62.5) which is 45 MHz.
Hi Geof, thank you so much for the time you took to explain this, really nice explanation. I will test it this and leave here the result, probably on another video, I have so many questions about the device, that probably will do a video answering it. But back to the samplling and frequency, it will nice to confirm what you say. Thanks again for being here, participating and watching! 👍💪
@@choosers5177 I don't have the Zoyi. There is a thread about it in the Test Equipment section of the forum on the eevblog site. Seems the firmware has some issues.
@@bobisyouruncle1 Did you not fully read my comment? The part where i wrote "Any input frequency above 62.5MHz will be aliased and folded back around 62.5MHz."
If we divide 250gs/20, we get 12.5 MHz. This is an approximate formula that can be used to determine the limit at which a complex shaped signal can be read without distortion. Or 125gs/20, for two channels. A sine wave is almost always displayed without distortion. The meander, a sawtooth waveform, shows more about the oscilloscope.
Depends entirely on the filter used to convert the point samples to the continuous waveform that is displayed on the screen. The theoretical lower limit for the divisor is 2. With a good filter the divisor can be as low as 2.5.
Hi! Thanks for the vid! Did you notice the test generator has a DC offset when feeding a sine wave? That's not generally ok when feeding a test tone to an audio equipment!
Due to the sampling rate the scope is only rated for 60Mhz when both channels are enabled. The phase offset is pretty bad though. It might not be great for judging timing on fast digital circuits.
"It's frustrating; the chinese engineers are incapable of developing a fully, ..."fully "functioning device. There always have to be compromises." A voice assistant is not necessary, but no phase offset is
Gracias por el video, buen trabajo y buena explicación, es un equipo con prestaciones básicas y suficientes para trabajos de mantenimiento, los que deseen mejor calidad no deben criticar y se deben comprar uno de marca certificada para lo cual pagarán 20 veces mas o quedarse con las ganas viendo otros videos.
Nice work. Wonder if we will get any firmware upgrades? No luck in dl the images to the computer? Would have been sweet to have some computer interface options. Did you get it to overlay signal over save for comparison? Seems limiting to not be able to compare or DL images if that is the case.
Hi, you have the overlay function based on what as saved, no connection to the PC. Don't know if that is something that they can solve with firmware upgrade. Thanks for watching.
My current firmware is V3.05. The value of the automatic measurement of the pulse width is displayed as a period. I asked Zeeweii to fix it. 私のは現在ファームウェア V3.05ですが パルス幅の自動測定の数値が周期表示です
Hugely helpful review, thanks! One thing I noted in the manual is that the multimeter cannot be used while charging? I want something I can leave plugged in to power the time - is it really the case that this won't work? Or is the battery life long enough that it's not an issue?
Hi, that is correct, I mention that in the video. But we are talking about only the multimeter. The battery last enough for me to record this during 2 days. But if you use it all day long, you have to charge it every day. Again, oscilloscope works fine connected to the power, only multimeter has that limitation. Thanks for watching.
commands voice are : "Multimeter AC voltage" for AC voltage ,,,,,"Multimeter Capacitance" for Capacitance ,,,,, "Multimeter diode" for diode ,,, "Turn off power" to shutdown ,,,, "test continuity" for measuring Continuity
Just read that scope and DMM can be used simultaneously. How about the signal gen? Is it possible to use all three together? Quite often I have my function generator, scope and a couple of DMMs of the bench and it takes up a lot of real estate.
Hi, yes it is possible to use the 3 at the same time. It will have a small window on the screen on oscilloscope mode and you can have the function generator also on while working with the other two. Thanks for watching.
Hi Elsa, I didn't quite understood your question. But generally speaking, this oscilloscope is isolated from the house mains/ground while operating on battery, so it make it easier to test devices connect to the ground, I don't know if this is the direction of your question, if not let me know. Thanks for watching.
Does your generator generate the correct phase? Maybe there is an error in the generator? Check it on another oscilloscope. Zeeweii makes good instruments. It's true that a multimeter is superfluous here.
Hi, I agree with you and I do recomend this device, if you watch the first video, I do say that Zeeweii is the underdog in this oscilloscope market, great devices, nice quality, but need better user support and marketing. I use for my tests my Owon XDG2100 Dual 100Mhz (independant) function generator. Is pretty nice, no problems in the test I made to all my other devices reviewed with it. But I'm not a electonics professional, I do this because I like and is my "passion", so I can make mistakes, totally open for corrections from you guys, always learning is my motto! Thanks for watching.
The phase error is evident with one signal fed to both inputs. The difference is 3ns. Not really a problem as you can take it into account once you know it exists.
Hi, yes I would. This device is pretty well build, accurate enough and with a nice set of functions and a decent price, so if you don't want to spend a lot of money, you'll get a oscilloscope, a multimeter and a function generator fairly accurate in a low price. Thanks for watching.
Olá Marcelo, eu pessoalmente gosto muito do DPOX180H, tem um ecrã maior o que no meu caso é algo importante, a vista já não é o que era. O DPO13D12 é um aparelho muito bom também e cheio de funcionalidades e ainda tem o multimetro e se isso for importante para ti, é uma excelente alternativa, o gerador de sinais também é bastante interessante, ficas com um "laboratório" num pequeno aparelho. Nunca esquecer que um aparelho como este também tem as suas limitações. Obrigado por assistires.
Hi, I don't have yet here the ZT703S for testing. It will come soon, generally speaking, I like more the form factor of ZT703S and the quality of the ZT702S is amazing, a very nice product. The Zeeweii is also nice but it is full of functions and while is portable, I think it was designed more to be on the desktop, so for me, are different products. Thanks for watching.
Hi David, for mine 12 year old also... 😁 but you can do a lot with this small device, as always it depends on your needs and what you're willing to pay, for the balance, this is a nice unit. Thanks for watching.
I think he's asking if the negative (ground) sides of the two channel inputs are separated, or connected together. (Looks to me like they share a common ground, though I have verified that...) @@TechCornerTV
Hey there, so, I have wandering hands 😁 maybe in my past I had a relative from italy that pass me the talking with the hands. Jokes a part, I can't be still, is not natural to me... sorry the epileptic attack and thanks for watching!
@@TechCornerTV Yes, your great-great-grandmother probably sinned with an Italian.🤣 It would be nice if manufacturers would put the truth in their brochures. What prevented him from specifying the real frequency of 75 MHz, not 120? It would have caused more confidence in the device.
Hi Fernando, in the past I use to test all the oscilloscopes with my Rigol 350Mhz probes to create a standard between test, but viewers complained that were not the supplied probes and it will be better to use the device probes, so I changed that. I agree better quality equipment is half way for better results, but since we are talking about the probe, it might get a bit better, but nothing really significant. Thanks for watching.
Thank you very much, then maybe it is not convenient to buy additional test leads, I guess I will wait a little longer to buy a cheap portable oscilloscope. Have a Nice day!
Спасибо большое друг, за обзор, поставил лайк и hello from Russhia))) To day iam buy this device and i very happy) voice control is very fun) double thank you, and like )
Hello! Thank you for your nice comment... and if you're buying it, please consider sponsoring the channel using the affiliate link... 😁 you pay the same! I hope you enjoy your new oscilloscope, have fun! Thanks for watching and the support!
This oscilloscope disappointed me. The fact that it has an extra multimeter function and voice control is okay. But the fact that it throws off the phase and incorrectly determines the frequency at 25 MHz is worse. It comes out in two channels up to 50 MHz in frequency.
Hi Igor, well to be honest, it should support 100Mhz one channel properly, the second channel always have the sampling rate divided by 2, so the results will be always worst. But I agree with you. Thanks for watching.
Instead of programmers playing with voice recognition, why not play with something more useful such as Real FFT measurements or even better, Decode for SPI, I2C and CAN with hex and ASCIi tables. THAT would be impressive! It's all just code right. It seems they have processor cycles to spare. It would be nice to get a peek inside.
Hi, let me start by saying that I really appreciate your input, truly. But allow me to disagree with you, this is a very nice device for hobbyist and the voice commands are not even listed on the features, is just a bonus that you get. As an oscilloscope, for a small one, is pretty decent, in my opinion. Thanks for watching.
Concerning the dual channel bandwidth test, it is not just the frequency counters that are incorrect above 50MHz input. Look at time 11:31. The inputs are 100MHz but the waveforms' periods are 4 divisions. Each division is 10ns. That means the waveforms are being displayed as 25MHz sine waves. This is all the classic symptoms of aliasing caused by the sampling rate being too low for the signal being investigated. There is only one A to D converter which is shared between the two channels when both are in use. That halves the sampling rate for each channel. It also explains why there is a phase difference between the two displayed channels. They are being sampled at different times but displayed as if they were sampled simultaneously.
The ADC is sampling at 250MHz. In two channel operation each channel is being sampled at 125MHz. The Nyquist rate is therefore 62.5MHz. Any input frequency above 62.5MHz will be aliased and folded back around 62.5MHz. Input 75MHz which is 12.5MHz above 62.5MHz and it will be alised to 12.5MHz below 62.5MHz which is 50 MHz. Input 100MHz which is 37.5MHz above 62.5MHz and it is alised to 62.5MHz minus 37.5MHz which is 25MHz. As further proof try input of say 80MHz. I predict that it will be displayed as 62.5 - (80-62.5) which is 45 MHz.
Hi Geof, thank you so much for the time you took to explain this, really nice explanation. I will test it this and leave here the result, probably on another video, I have so many questions about the device, that probably will do a video answering it. But back to the samplling and frequency, it will nice to confirm what you say. Thanks again for being here, participating and watching! 👍💪
Grettings. Which one do you recomend. This or zoyi zt 703s.
@@choosers5177 I don't have the Zoyi. There is a thread about it in the Test Equipment section of the forum on the eevblog site. Seems the firmware has some issues.
This is a 120mhz scope, therefore testing it above 60mhz with both channels simultaneously exceeds the limit.
@@bobisyouruncle1 Did you not fully read my comment? The part where i wrote "Any input frequency above 62.5MHz will be aliased and folded back around 62.5MHz."
If we divide 250gs/20, we get 12.5 MHz. This is an approximate formula that can be used to determine the limit at which a complex shaped signal can be read without distortion.
Or 125gs/20, for two channels.
A sine wave is almost always displayed without distortion. The meander, a sawtooth waveform, shows more about the oscilloscope.
Hi Andrei, good point, will take more attention in future reviews to use more the sawtooth. Thanks for watching.
Depends entirely on the filter used to convert the point samples to the continuous waveform that is displayed on the screen. The theoretical lower limit for the divisor is 2. With a good filter the divisor can be as low as 2.5.
Hi! Thanks for the vid! Did you notice the test generator has a DC offset when feeding a sine wave? That's not generally ok when feeding a test tone to an audio equipment!
sounds like the voice on the dfrobot gravity df2301q speech recogniser board. wonder if they share a common supplier
Hi, it might be. Thanks for watching.
Due to the sampling rate the scope is only rated for 60Mhz when both channels are enabled. The phase offset is pretty bad though. It might not be great for judging timing on fast digital circuits.
Hi, hmm... I got you, maybe. Thanks for watching.
"It's frustrating; the chinese engineers are incapable of developing a fully, ..."fully "functioning device. There always have to be compromises." A voice assistant is not necessary, but no phase offset is
Hi, good point in your comment! Thanks for watching.
O modelo tem restrição de banda para 2 canais.
Atinge 120mhz apenas no ch1. Ao utilizar 2 canais ele limita ambos a 60Mhz.
Gracias por el video, buen trabajo y buena explicación, es un equipo con prestaciones básicas y suficientes para trabajos de mantenimiento, los que deseen mejor calidad no deben criticar y se deben comprar uno de marca certificada para lo cual pagarán 20 veces mas o quedarse con las ganas viendo otros videos.
In previous vlog you mentioned some windows along close to charging port is it's speaker for Voice Assistant !
Thank you!
Hi, thank you so much for your input and you're right! Thanks for watching.
Thank you so much!
Did you try a USB-C to USB-C cable? Some USB-C ports only work with USB-A to C adapter cables, as two resistors were omitted.
Hi, I tried and didn't have a problem. Thanks for watching.
Nice work. Wonder if we will get any firmware upgrades? No luck in dl the images to the computer? Would have been sweet to have some computer interface options. Did you get it to overlay signal over save for comparison? Seems limiting to not be able to compare or DL images if that is the case.
Hi, you have the overlay function based on what as saved, no connection to the PC. Don't know if that is something that they can solve with firmware upgrade. Thanks for watching.
My current firmware is V3.05.
The value of the automatic measurement of the pulse width is displayed as a period.
I asked Zeeweii to fix it.
私のは現在ファームウェア V3.05ですが
パルス幅の自動測定の数値が周期表示です
Hugely helpful review, thanks! One thing I noted in the manual is that the multimeter cannot be used while charging? I want something I can leave plugged in to power the time - is it really the case that this won't work? Or is the battery life long enough that it's not an issue?
Hi, that is correct, I mention that in the video. But we are talking about only the multimeter. The battery last enough for me to record this during 2 days. But if you use it all day long, you have to charge it every day. Again, oscilloscope works fine connected to the power, only multimeter has that limitation. Thanks for watching.
commands voice are : "Multimeter AC voltage" for AC voltage ,,,,,"Multimeter Capacitance" for Capacitance ,,,,, "Multimeter diode" for diode ,,, "Turn off power" to shutdown ,,,, "test continuity" for measuring Continuity
The second channel was set to DC coupling during the test. This may cause the phase difference.
Hi, thank you for pointing it out, it missed me! 🤦♀️ I really appreciate your feedback, will be more carefull next time. Thanks for watching.
No. Selection of AC or DC coupling does not change the phase difference.
Osobiście waham się pomiędzy DSO3D12, a ZOYI ZT-703S - które urządzenie Pana zdaniem jest lepsze ?
Can you use the scope and DMM at the same time?
Just read that scope and DMM can be used simultaneously.
How about the signal gen?
Is it possible to use all three together?
Quite often I have my function generator, scope and a couple of DMMs of the bench and it takes up a lot of real estate.
Hi, yes it is possible to use the 3 at the same time. It will have a small window on the screen on oscilloscope mode and you can have the function generator also on while working with the other two. Thanks for watching.
@@TechCornerTV many thanks for your reply.
Keep up the good work!
Hello, how can I increase the volume?
Hi Alek, no, I don't. Sorry. Thanks for watching.
Good morning; could you tell me how to delete an image view?
Hi, I show in the video, go to the image manager and you have there the menu to delete the image. Thanks for watching.
Can u use it on smpsu where you have a ‘hot ground’ in the primary section?
Hi Elsa, I didn't quite understood your question. But generally speaking, this oscilloscope is isolated from the house mains/ground while operating on battery, so it make it easier to test devices connect to the ground, I don't know if this is the direction of your question, if not let me know. Thanks for watching.
Does your generator generate the correct phase? Maybe there is an error in the generator? Check it on another oscilloscope. Zeeweii makes good instruments. It's true that a multimeter is superfluous here.
Hi, I agree with you and I do recomend this device, if you watch the first video, I do say that Zeeweii is the underdog in this oscilloscope market, great devices, nice quality, but need better user support and marketing. I use for my tests my Owon XDG2100 Dual 100Mhz (independant) function generator. Is pretty nice, no problems in the test I made to all my other devices reviewed with it. But I'm not a electonics professional, I do this because I like and is my "passion", so I can make mistakes, totally open for corrections from you guys, always learning is my motto! Thanks for watching.
The phase error is evident with one signal fed to both inputs. The difference is 3ns. Not really a problem as you can take it into account once you know it exists.
Здравствуйте. Посоветуете ли Вы данный прибор для новичка и простых ремонтов? Заранее благодарю за ответ. ✌️
Hi, yes I would. This device is pretty well build, accurate enough and with a nice set of functions and a decent price, so if you don't want to spend a lot of money, you'll get a oscilloscope, a multimeter and a function generator fairly accurate in a low price. Thanks for watching.
Estou na dúvida de qual comprar, me dê uma sugestão, o dpox180 ou dso3d12?
Olá Marcelo, eu pessoalmente gosto muito do DPOX180H, tem um ecrã maior o que no meu caso é algo importante, a vista já não é o que era. O DPO13D12 é um aparelho muito bom também e cheio de funcionalidades e ainda tem o multimetro e se isso for importante para ti, é uma excelente alternativa, o gerador de sinais também é bastante interessante, ficas com um "laboratório" num pequeno aparelho. Nunca esquecer que um aparelho como este também tem as suas limitações. Obrigado por assistires.
Grettings. Which one do you recomend. This or zoyi zt 703s.
Hi, I don't have yet here the ZT703S for testing. It will come soon, generally speaking, I like more the form factor of ZT703S and the quality of the ZT702S is amazing, a very nice product. The Zeeweii is also nice but it is full of functions and while is portable, I think it was designed more to be on the desktop, so for me, are different products. Thanks for watching.
it is a suitable toy for my 10 years old son.
Hi David, for mine 12 year old also... 😁 but you can do a lot with this small device, as always it depends on your needs and what you're willing to pay, for the balance, this is a nice unit. Thanks for watching.
Only if he’s an underachiever 😂
Which better this or ZOYI ZT-703S?
Hi, I just received the Zoyi ZT-703S and will have the chance to test and review in the next days, stay tunned. Thanks for watching.
Is tow chanal inpot spritely or negativ signal conect together
Hi, sorry I didn't get your question, but thanks for watching!
I think he's asking if the negative (ground) sides of the two channel inputs are separated, or connected together. (Looks to me like they share a common ground, though I have verified that...) @@TechCornerTV
Is DMM True RMS ?
Hi, I was almost sure it was, but now I'm on the edge, I don't find that information anywhere. I'll dig further on this. Thanks for watching.
Прекрасный прибор за свои деньги 💸. Тоже себе заказал. Надеюсь, что не разочарует 😂
Hi, I hope that will serve you well and you'll enjoy it. Thanks for watching!
he almost hypnotized me with his hands. But I had an epileptic attack.
Hey there, so, I have wandering hands 😁 maybe in my past I had a relative from italy that pass me the talking with the hands. Jokes a part, I can't be still, is not natural to me... sorry the epileptic attack and thanks for watching!
@@TechCornerTV Yes, your great-great-grandmother probably sinned with an Italian.🤣 It would be nice if manufacturers would put the truth in their brochures. What prevented him from specifying the real frequency of 75 MHz, not 120? It would have caused more confidence in the device.
if you change the probes form200 mhz Is there any bandwidth performance?
Hi Fernando, in the past I use to test all the oscilloscopes with my Rigol 350Mhz probes to create a standard between test, but viewers complained that were not the supplied probes and it will be better to use the device probes, so I changed that. I agree better quality equipment is half way for better results, but since we are talking about the probe, it might get a bit better, but nothing really significant. Thanks for watching.
Thank you very much, then maybe it is not convenient to buy additional test leads, I guess I will wait a little longer to buy a cheap portable oscilloscope. Have a Nice day!
If you could even find 200 milli Hertz probes the performance would be very bad. (m=0.001, M=1,000,000)
Спасибо большое друг, за обзор, поставил лайк и hello from Russhia))) To day iam buy this device and i very happy) voice control is very fun) double thank you, and like )
Hello! Thank you for your nice comment... and if you're buying it, please consider sponsoring the channel using the affiliate link... 😁 you pay the same! I hope you enjoy your new oscilloscope, have fun! Thanks for watching and the support!
This oscilloscope disappointed me. The fact that it has an extra multimeter function and voice control is okay. But the fact that it throws off the phase and incorrectly determines the frequency at 25 MHz is worse. It comes out in two channels up to 50 MHz in frequency.
Hi Igor, well to be honest, it should support 100Mhz one channel properly, the second channel always have the sampling rate divided by 2, so the results will be always worst. But I agree with you. Thanks for watching.
Instead of programmers playing with voice recognition, why not play with something more useful such as Real FFT measurements or even better, Decode for SPI, I2C and CAN with hex and ASCIi tables.
THAT would be impressive!
It's all just code right. It seems they have processor cycles to spare. It would be nice to get a peek inside.
@@TechCornerTV Hello, how can I increase the volume?
@@alekseyretslav1062 You cannot.
Thank you very much
Добре время суток всем кто читает мой комент. Видео познавательное. Больше спасибо! Скажите пожалуйста можно ли подключить через USB порт к ноутбук???
Hi, thank you for your nice comment and support. It's not possible to connect to a PC/Laptop. Thanks for watching.
I think the voice assistant needs a little work 😊
Warum nicht in deutsch
Hi, you mean the video or the AI voice? The video should be dubbed pretty soon to german. Thanks for watching.
OK let’s be blunt - POS don’t buy it - the end.
Hi, let me start by saying that I really appreciate your input, truly. But allow me to disagree with you, this is a very nice device for hobbyist and the voice commands are not even listed on the features, is just a bonus that you get. As an oscilloscope, for a small one, is pretty decent, in my opinion. Thanks for watching.