Can my Rigol dg1022Z counter be defective ? - Page 1
Forum section: electronics / testgear

author: Yannick99
author_rank: Contributor
timestamp: November 13, 2023, 05:20:00 pm
content: Hi everybody,I'm playing with the fisrt time with the counter of my DG1022. I dont know if it's me but it's really hard to use.For exemple. I setup a simple square waveform from ch1 and enter it in the counter with a coax. 1 Mhz. 2v peak. No offset.I check the output signal on scope.... very clean 0 to 2v 50% duty square wave.To be able to read anything I must set the trigger sense to 95%, level to 0 and coupling is DC. The gate time change only the accuracy.If I change trigger sens to 85%... result jump all over the placeIf I rise trigger lever to only 100mv... nothingIf I lower the frequency to 100khz or 1Khz same result.If I probe with my dm3068 (On Freq as well), it is showing me the right frequency.And this is just one exemple. Is it me ? Or it's very hard use. It's pratically useless.I looked on other thread but nobody is talking about it. It's why I think it is maybe defective ?Thank youYannick

author: AVGresponding
author_rank: Super Contributor
timestamp: November 13, 2023, 05:30:27 pm
content: Have you tried changing it to a sine wave? Square waves have a lot of harmonics, your counter might be sensitive enough to be confused by them.

author: Yannick99
author_rank: Contributor
timestamp: November 13, 2023, 07:55:44 pm
content: Yes of course, sine wave 1vpp gave me the same thing. If I rise to 2Vpp I can lover the trigger sens to 75%.As well with a sinewave I chossing ac coupling instead DC but anyway I have the same problem in both.It's like my signal is detected very dim or fadeor too low ?Yannick

author: xrunner
author_rank: Super Contributor
timestamp: November 13, 2023, 08:07:05 pm
content: Quote from: Yannick99 on November 13, 2023, 05:20:00 pmI had a DG1022 back in 2016. I had problems with the counter as well. The thread is linked below. Mostly it wasn't accurate even with an external GPSDO reference. I reported it to Rigol and they worked a deal for me to return it and get a DG1032Z plus a few $$. I just don't think the counter in those DG1022s are any good at all.https://www.eevblog.com/forum/testgear/rigol-dg1022a-function-gen-frequency-counter-function/msg926368/#msg926368

author: Yannick99
author_rank: Contributor
timestamp: November 13, 2023, 08:58:40 pm
content: Yes I read your thread. I think I have something similar. I have the new model but I do not know if the internal hardware is updated or better. If I look my reading, I don't think so.

author: bd139
author_rank: Super Contributor
timestamp: November 13, 2023, 09:01:42 pm
content: Ex DG1022 owner. The counter is shit. Ex DG800 owner. The counters are shit too. Ex Siglent SDG1000 owner. The counter is terrible too.Advice: buy a separate box. 1980s HP junker off ebay is good.

author: Yannick99
author_rank: Contributor
timestamp: November 13, 2023, 09:20:16 pm
content: I know what you mean. I have my old HP. Same signal, same cable.I thought with time, thing should be betterno...Yannick

author: Circlotron
author_rank: Super Contributor
timestamp: November 13, 2023, 11:19:34 pm
content: I'll have to check mine when I get home.You'd think the sig gen and the counter would run off the same reference so there would always be zero "error" even if the reference drifted.Edit -> I misread the title. I thought it was talking about the later DG1022Z.

author: Yannick99
author_rank: Contributor
timestamp: November 14, 2023, 12:07:26 am
content: Exactly, I run it under external gpsdo but, the reference is the same. I sould be reading bang on. Even if I were using internal oscillator. But the problem isn't just that. It is very hard to bring the counter counting. Let me know please. Thank you, appreciated.Yannick

author: Yannick99
author_rank: Contributor
timestamp: November 14, 2023, 02:27:41 pm
content: Quote from: Circlotron on November 13, 2023, 11:19:34 pmYes sorry it's dg1022Z

author: Njk
author_rank: Frequent Contributor
timestamp: November 14, 2023, 05:33:24 pm
content: Anyway for DG800 I witnessed it's working somehow. Perhaps there can be variations from one sample to the other.

author: bd139
author_rank: Super Contributor
timestamp: November 14, 2023, 09:11:18 pm
content: It'll work for a bit untily you accidentally exceed the miniscule voltage it'll handle before dying

author: Njk
author_rank: Frequent Contributor
timestamp: November 14, 2023, 10:25:50 pm
content: Well, there is some protection in the form of clamping diodes. Although the input range is quite limited indeed and generally it's not a unique instrument in that regard. As usual, RTFM before use.

author: Circlotron
author_rank: Super Contributor
timestamp: November 14, 2023, 10:40:34 pm
content: Quote from: Yannick99 on November 14, 2023, 02:27:41 pmThe running title changes from post #10 onward, oddly enough….Okay, tried out mine last night and and the counter seems to be very level sensitive. Started off with 10V p/p sine wave and the counter sat at zero. At 2V it was a bit jumpy and wouldn’t go above 1.3MHz. At 1V p/p it worked great all the way to 25MHz. Input clamping diodes were mentioned. I’ll put the scope on it and see if that is happening.

author: Yannick99
author_rank: Contributor
timestamp: November 15, 2023, 02:00:29 pm
content: QuoteYes I corrected the title :pQuoteDo you remember the trigger sense and trigger level it was set ?QuoteOk thanks, let me know!Yannick

author: Yannick99
author_rank: Contributor
timestamp: February 01, 2024, 12:32:19 am
content: Finally, I fixed it. It was indeed defective.The input resistor 26.1 Ohm was open. I do not really know how this happen but anyway. It's fixed and the counter is working well.Yannick

author: Circlotron
author_rank: Super Contributor
timestamp: February 01, 2024, 03:50:34 am
content: If you measure DC resistance from counter input to ground, what do you find? If other people have the same problem they can check this without opening the unit up.

author: Yannick99
author_rank: Contributor
timestamp: February 01, 2024, 01:46:23 pm
content: Yes sure it's a good idea, could be helpful.The input resistance on the counter bnc connector (center to GND) is 2.361 MegOhm at Off state and 1.2 Meg when powered On.Before the replacement, it was just Open, OL.The resistor replaced was a 26.1 Ohm in a 1206 Package named Counter-InYannick