Why the user should be doing this. The fact that the issue has been known for two years and Rigol did not bother fixing it and even not removed/hide that option in the menu to me is a indication that Rigol is still a Mickey Mouse company. If i have a instrument on my bench i want to use it and trust it, not fight with it.
Hello everyone. I am not sure if you saw the Rigol response back. If not here it is:
https://www.tequipment.net/assets/1/7/EEVBlog_message1.pdf
So you trying to tell me that next time when i buy car i will get no reverse gear when i aswer in survey "i never use reverse gear" I paid for function introduced in datasheet/user manual/product description and you guys asking such stupid questions?
Fix that shit in the fw or replace broken mainbaords, and stop asking such stupid things. Every other manufacturer (and even half of the cheap DIY china scopes) is capable of implementing AC coupled trigger/channel, so where is the problem for Rigol?
Rigol is still a Mickey Mouse company. If i have a instrument on my bench i want to use it and trust it, not fight with it.
Feel free to spend a lot more money...it's your perogative.
Feel free to spend a lot more money...it's your perogative.
I spent $3900 on a 4000 series, been fighting with Rigol for almost a year to get issues fixed, they don't care.
Rigol is making 4-channel, 100MHz 'scopes and selling them for $400.
Your rant just sounds like you bought a half price horse and are complaining about the teeth. I'm sure most countries have a saying about that.
Feel free to spend a lot more money...it's your perogative.
I spent $3900 on a 4000 series, been fighting with Rigol for almost a year to get issues fixed, they don't care.
In such situations I do very simple.
My personal belief, right or wrong, is to just be honest.
I'm honest on the first try. So I'm honest until another party is honest too.
I'm honest on the first try. So I'm honest until another party is honest too.
Honesty and morals don't take a day off. Just because someone else or some company decides to lie and deceive never is an excuse to do the same.
- How often do you use AC coupling on your scope?
every fucking day
- When you use AC coupling on a channel, why do you do it?
not your fucking business, and btw, wtf you mean with this question?
So you trying to tell me that next time when i buy car i will get no reverse gear when i aswer in survey "i never use reverse gear" I paid for function introduced in datasheet/user manual/product description and you guys asking such stupid questions?
Bad analogy. It's not as fundamentally broken as "no reverse gear".
It's more like "the number plate light isn't as bright as I normally like it".
I don't get why the LF Reject improves the stability of the Jitter, LF Reject removes the lower frequencies (< ~20khz?). This negates IMO any concept that it's a sample rate issue or such. It's almost like some stray signal is getting in to the trigger circuit or perhaps a DC offset on some op-amp or something. IDK. It's just weird.
I don't get why the LF Reject improves the stability of the Jitter, LF Reject removes the lower frequencies (< ~20khz?). This negates IMO any concept that it's a sample rate issue or such. It's almost like some stray signal is getting in to the trigger circuit or perhaps a DC offset on some op-amp or something. IDK. It's just weird.
AC trigger coupling is just low frequency reject with a lower cutoff frequency so it works below 50/60 Hz. With such a low cutoff frequency, if the filter (DSP in the FPGA?) is reset after every trigger, then it may not have enough time to settle before the new trigger occurs. The low frequency reject trigger settles much more quickly.
You can sometimes see this happen on analog oscilloscopes which support both; in AC coupled trigger mode, the trigger position will initially visibly shift horizontally while in low frequency rejection mode, it settles much faster. A 30 Hz low frequency cutoff has a time constant of 11.7 milliseconds while a 30 kHz low frequency cutoff has a time constant of 11.7 microseconds.
AC trigger coupling is just low frequency reject with a lower cutoff frequency so it works below 50/60 Hz. With such a low cutoff frequency, if the filter (DSP in the FPGA?) is reset after every trigger, then it may not have enough time to settle before the new trigger occurs. The low frequency reject trigger settles much more quickly.
You can sometimes see this happen on analog oscilloscopes which support both; in AC coupled trigger mode, the trigger position will initially visibly shift horizontally while in low frequency rejection mode, it settles much faster. A 30 Hz low frequency cutoff has a time constant of 11.7 milliseconds while a 30 kHz low frequency cutoff has a time constant of 11.7 microseconds.
I have a 2465B in mint condition. Has the same LF and HF rejects. I was under the impression the LF reject removed low frequencies from the trigger path while HF Reject did the opposite (i.e. removed high frequencies). So still it seams odd the LF Reject stabilizes the jutter to a degree while the HF Reject does not. Makes me think their is a low freq element that's impacting things a bit. Naturally my Tek doesn't suffer from these issues with the same signals.
It's more like "the number plate light isn't as bright as I normally like it".
Every other manufacturer (and even half of the cheap DIY china scopes) is capable of implementing AC coupled trigger/channel, so where is the problem for Rigol?
I think tinhead's analogy is pretty good. How often do you use reverse gear? You can always park where you do not need reverse or get out and push your car backwards.
AC trigger coupling is just low frequency reject with a lower cutoff frequency so it works below 50/60 Hz. With such a low cutoff frequency, if the filter (DSP in the FPGA?) is reset after every trigger, then it may not have enough time to settle before the new trigger occurs. The low frequency reject trigger settles much more quickly.
You can sometimes see this happen on analog oscilloscopes which support both; in AC coupled trigger mode, the trigger position will initially visibly shift horizontally while in low frequency rejection mode, it settles much faster. A 30 Hz low frequency cutoff has a time constant of 11.7 milliseconds while a 30 kHz low frequency cutoff has a time constant of 11.7 microseconds.
I have a 2465B in mint condition. Has the same LF and HF rejects. I was under the impression the LF reject removed low frequencies from the trigger path while HF Reject did the opposite (i.e. removed high frequencies). So still it seams odd the LF Reject stabilizes the jutter to a degree while the HF Reject does not. Makes me think their is a low freq element that's impacting things a bit. Naturally my Tek doesn't suffer from these issues with the same signals.
Low frequency reject is just another way to say high pass filter and high frequency reject is just another way to saw low pass filter. The difference between AC coupling and low frequency reject is just the cutoff frequency.
Triggers work best on fast edges which will produce the lowest jitter but sometimes you want to deliberately ignore high frequencies or low frequencies. For example triggering on the AC line will usually be improved with high frequency reject but if you want to trigger on a high frequency glitch which is on the AC line, low frequency reject would be appropriate.