Sigkent SDG2000x time base accuracy - Page 1
Forum section: electronics / testgear

author: trevwhite
author_rank: Frequent Contributor
timestamp: January 10, 2023, 02:38:21 pm
content: Hi allThe datasheet for the SDG2000x series states 1ppm accuracy and aging over 10 years to be 3.5ppm. Sounds very impressive. Anyone know if the unit lives up to this or what circuitry is inside that gives confidence in this figure?Most other sig gens from rigol and siglent don’t give aging info from what I can see.Thanks

author: tautech
author_rank: Super Contributor
timestamp: January 10, 2023, 06:40:12 pm
content: Quote from: trevwhite on January 10, 2023, 02:38:21 pmConsidering these are an 8yr old product and still a popular seller one has to realise buy now there is a wealth of data points and history with these products to have confidence in published specs.Also note datasheets date stamps on thew HQ website that indicates they are recent revisions with latest specs.QuoteSDG1000X has the least spec of 25ppm but it is their cheapest well featured ARB.SDG6000X P8 has the exact same spec as SDS2000Xhttps://int.siglent.com/u_file/download/22_07_28/SDG6000X_DataSheet_DS0206X-E02C.pdf

author: trevwhite
author_rank: Frequent Contributor
timestamp: January 11, 2023, 01:18:47 pm
content: Thanks for the reply. Not sure silence from the general public can be taken to mean the impressive spec is true. I watched Dave’s tear down from years ago and he didn’t recognize the oscillator inside. The PCB looked dual tracked for a through hole module.Be really useful to know what part is inside them?Trev

author: colorado.rob
author_rank: Frequent Contributor
timestamp: January 11, 2023, 05:05:00 pm
content: I've had mine for 5+ years. I use the frequency counter and signal generator extensively. It is still typically < 1ppm (+/- 0.5ppm, depends on office temperature). If I need better accuracy, I use a GPS-DO as an external reference.

author: trevwhite
author_rank: Frequent Contributor
timestamp: January 11, 2023, 06:01:02 pm
content: Wow, that’s great. Thanks

author: bdunham7
author_rank: Super Contributor
timestamp: January 11, 2023, 06:37:55 pm
content: The SDG2000X clock is really pretty good--at least mine is. It has some sort of trimmable TCXO (VCTCXO or DCTCXO) which can be adjusted from the front panel with not-so-secret commands that I don't remember right now. Once trimmed to perfection, it appears to be very stable and precise and not requiring any warmup. I just checked mine, it is +0.06ppm after 5 minutes, it was +0.11ppm right at startup.

author: mawyatt
author_rank: Super Contributor
timestamp: January 11, 2023, 08:29:23 pm
content: We have the SDG2000X and 6000X, and both get periodic trimming to the best 10MHz source we have in house. They are both quite stable, altho the 6000X seems to have less "random walk" than the 2000X.Very precise & useful AWGs, and a great value!!Best,

author: trevwhite
author_rank: Frequent Contributor
timestamp: January 11, 2023, 10:22:59 pm
content: Thanks, have order one.

author: trevwhite
author_rank: Frequent Contributor
timestamp: March 01, 2023, 10:56:59 am
content: Thought I would put an update on this. I purchased the unit and the timebase is super stable and accurate. Really happy with the unit.

author: hpw
author_rank: Frequent Contributor
timestamp: March 01, 2023, 12:00:51 pm
content: Quote from: bdunham7 on January 11, 2023, 06:37:55 pmThis what I need!While after FW reset, my frequency gets some ppm offSo please any information would be nice to haveHp

author: Zenith
author_rank: Frequent Contributor
timestamp: March 02, 2023, 05:46:33 pm
content: It's in one of the service manual revisions but I couldn't find it in the current one.See herehttps://www.eevblog.com/forum/testgear/the-siglent-sdg2042x-thread/msg1243552/#msg1243552Connect 10MHz from your GPSDO to the counter input, set the AWG to counter mode and make sure it works. It's probably best if the AWG has been left on to warm up for at least 10 minutes.Then Utility=>System=>page 2=>System Info=>123654=>Time Base Calibration.Then you can alter the DAC code to tune the frequency.There's a frequency display on that screen but it's a bit coarse unless you are really far out.Then Accept and back into counter mode to check. Rinse and repeat until you get it as close as you can. You could also check the AWG output with a scope and GPSDO or a counter with an external reference.There's also an Auto Set when you get to the screen with the DAC code. I tried it and it didn't seem to do much. I altered the DAC code.When I bought my SDG2000X a few months back it was within about 0.4 ppm, which is well within the maker's spec. After calibrating the timebase it's less than 0.01ppm. It will be interesting to see how long it stays there.0.4ppm is pretty good and enough for just about anything I want to use it for with its internal clock. Being able to adjust it to less is gratifying.

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: March 02, 2023, 07:09:11 pm
content: Interesting catch, I just noticed they pulled the entire section on calibration and adjustment off the latest release of the service manual, all there's left is the performance verification, which is unfortunate. As calibration and adjustment is perhaps the section most people would use on an annual basis.

author: hpw
author_rank: Frequent Contributor
timestamp: March 02, 2023, 07:51:44 pm
content: Quote from: NoisyBoy on March 02, 2023, 07:09:11 pmMay one chancehttps://www.batronix.com/files/Siglent/Funktionsgeneratoren/SDG2000X/SDG2000X_ServiceManual_EN.pdfBelow the pictures of that page O;)... about the DAC code, it is a mystery...

author: Zenith
author_rank: Frequent Contributor
timestamp: March 02, 2023, 08:29:17 pm
content: My DAC code was 16281 when I started and I found 16326 was the best value, compared against the GPSDO. I'm slightly surprised it wasn't better adjusted in the factory. It did take a good 20 minutes of messing about to get it right. Maybe that's why.As the DAC code increases, the reference frequency decreases. Once, I miss-keyed it as 1632 and the reference frequency was far too high. I expect you can run out of adjustment with old units as with OCXOs.All you have a right to expect is that it's within 1ppm and it will age to within 3.5ppm in ten years, and no more. For most things you'd use a function generator for, that's pretty damned good. If it's not up to your exacting standards, you can use an external reference.Your mileage may vary of course. I may have a particularly good TCXO - so far.