Siglent SDG5082 Overview Video - Page 1
Forum section: electronics / testgear

author: grego
author_rank: Frequent Contributor
timestamp: August 03, 2013, 03:33:56 pm
content: For those interested, I did a brief overview of the new'ish Siglent SDG5082 function generator. If you've got specific questions let me know and I'll do a follow-up video.

author: rf-loop
author_rank: Super Contributor
timestamp: August 04, 2013, 07:59:10 am
content: Nice video.As you there told (starting time position 11:20)"HP 53181A is out of calibration"(btw, even with valid cal it depends what internal freq reference it have it may show less or more freq error. )But other thing also. It is 10 digit per second counter, same as my 53131A. You have there quite short gate time so last digits are "garbage". I have HP 53131A (two channel) what are around same class of accuracy. Normally I use external reference if I need better absolute accuracy but in my unit there is option 010 Owen what give very good short time stability. But with these equipments can not measure example Siglent SDG short time stability (under 1s period due to 500ps resolution)Initial accuracy for SDG5000 internal reference is +/- 0.3ppm (used TCXO datasheet) But careful with this. There is not promise that all SDG use always exactly same manufacturer same class TCXO. (it is also good to know that today TCXO's may be very very good, in class 10ppb or something like this)In video I look gate indicator. Is it some kind of interference with video frame rate or is it really "random". If it is random in real life have you checked it trigs ok.--------------------------------------------Not comment for this video but somehow related to this freq measurement.Individual SDG5000 what I have tested it have been around 0.1ppm too high. (around 1Hz @ 10MHz. ) In test thread there can find table about SDG 10MHz reference accuracy in unit what I have tested.TCXO data:Yesterday I did two play experiments.I take 50 00 000 Hz signal from HP/Agilent 8644B (what have also exellent reference)Then I take 50 000 000 Hz from SDG.Then take both to oscilloscope and trig to HP signal (shutted off from display) and SDG signal other channel (displayed). Then fine adjust djust HP so that they are as close as possible same frequency in longer time. (fine adjust for this can not do with SDG due to lack of enough adjustment resolution)Then looked SDG signal so that one cycle is 10 horizontal div's (SDG signal drift around left and right randomly different amount and different speeds.. "fluctuate")Then I adjust HP scope persistence for 1000ms. With this test I watch scope screen around 15 minutes fixedly. Maximum freq difference in one second "time window" was <0.3Hz (horizontal 3 div persistence "tail") With these tools can not go to more short times (persistence can adjust but resolution is not enough and detect with eyes from screen is uncertain)Other play experiment was mixing 50MHz from SDG as LO and HP 50.001MHz as RF in. IF output around 1kHz. I look it with old HP oscilloscope what have nice resolution FFT.I leave this system to around half hour lounge time alone. When I come back.. on the screen 1kHz peak (infinite persistence on) trace was around inside 1Hz. (FFT resolution <100mHz and window around 980 - 1020Hz (4Hz per div))

author: grego
author_rank: Frequent Contributor
timestamp: August 04, 2013, 11:54:07 am
content: Yup. I didn't want anyone to take that HP as gospel since its out of cal. However being able to check std dev is still fine since its rate of change for that rather than an absolute measurement.Bottom line is the Siglent is pretty good bang for buck as a function generator. I would say its a better bang for your buck than the Rigol or Instek. The only drawback is if you have a problem with it it has to go back to China and that can be a problem for folks.

author: rf-loop
author_rank: Super Contributor
timestamp: August 04, 2013, 02:33:15 pm
content: Quote from: grego on August 04, 2013, 11:54:07 amThis HP out of cal is NOT problem at all here. My comment mean just this, so that someone who do not listen carefully may think Siglent may have so much offset or these last digits randoms, partially if not nearly all is becouse HP can not realiable count these all displayed digits in this short gate time. Other hand, even if HP show exactly right - error is under 1ppmand specs are (for one year) +/- 2ppm. (at 80MHz +/- 160Hz)Why need send back to China? Perhaps in some cases and depends where from it is. I do not know exactly true current policy for spare parts.But example if my local customer Siglent equipment PSU fails. I will call to Siglent and ask what to do and I think mostly it go so that wait after new PSU arrive and swap.I hope Siglent also do some developing for these practices for rare but possible warranty issues outside of China.It is part of product - and important part.It was good you rise also this question up on table.

author: Rosendorfer
author_rank: Regular Contributor
timestamp: August 04, 2013, 11:16:01 pm
content: Hi GregoCould You have a closer look if there is a way to "synchronise" 2 channels ?Like synchronising 2 channels to the same frequency, with set up constant phase shift, while being able to play with frequency.Rosendorfer

author: grego
author_rank: Frequent Contributor
timestamp: August 05, 2013, 12:09:18 am
content: I plan to. I think I mentioned in the video that I wasn't sure about that but yeah it's something I need to try to find.*edit* doesn't look like you can sync the channels which is a bit of a drag but you can't have everything at this price point. I will keep digging. The manual is not the most elaborate one out there.

author: tinhead
author_rank: Super Contributor
timestamp: August 05, 2013, 01:07:18 am
content: Try following: on the back side there is sync out, it can be set to send sync signal from channel one. I think the gate in can be assigned to channel 2, so when you connect sync out with gate in then you will get synched channels.

author: grego
author_rank: Frequent Contributor
timestamp: August 05, 2013, 01:26:53 am
content: That should work - I was looking for a straightforward sync like on the Agilent (ie, front panel sync). I'm going to hook the sync out up and give that a whirl. Stay tuned - I'll post scope output once I'm done.

author: Rosendorfer
author_rank: Regular Contributor
timestamp: August 06, 2013, 01:57:52 pm
content: Hi GregIf possible would be pretty interested.I have smaller Siglent gen SDG1025 and have found out that without possibility of channel syncing 2 channels have rather limited use.As per sync out have a look as in my SDG1025 there are 2 sync out outputs with different behaviour.Rosendorfer

author: Electro Fan
author_rank: Super Contributor
timestamp: August 06, 2013, 08:12:20 pm
content: Quote from: Rosendorfer on August 04, 2013, 11:16:01 pmNice video Greg. Thanks+ 2 on the interest in learning more about the 2 channel synchronization capabilities

author: grego
author_rank: Frequent Contributor
timestamp: August 06, 2013, 08:17:00 pm
content: Yeah I'll be doing the sync test either this evening or tomorrow - just been a little busy of late.

author: grego
author_rank: Frequent Contributor
timestamp: August 07, 2013, 12:00:00 am
content: Ok - I've tried and maybe I'm just an idiot but there does not appear to be any way to sync the channels. The manual seems to indicate that you can trigger, but it looks like only certain things accept an external trigger source like modulation, burst, etc. I have connected from the sync out to the trigger in and set the sync out to match channel 1 in all cases. The problem is the "standard" waveforms don't have a choice to use an external trigger as far as I can see.The two channels appear to be out of phase by about 11-13 degrees. Screen shots attached. The first is the two 10Mhz sine waves showing the phase. The second shows the output from the sync-out based on channel one.

author: jpb
author_rank: Super Contributor
timestamp: August 07, 2013, 09:27:24 am
content: Quote from: grego on August 07, 2013, 12:00:00 amLooking at the manual, the trigger input can take up to 350nsecs to respond so synching the channels via the sync out probably won't work very well anyway. I notice that in section 2.16 that there is a built-in help item (9) "How to synchronize multiple instruments" - it might be worth looking at that.I suspect the answer is you need to do it manually by measuring the phase difference on a scope and then adjusting the start phase of one of the channels on the instrument. That is ok at one frequency but may drift at other frequencies.I wonder if having different memory sizes for each channel affects synchronization at all (if there is some tiny shift each time the memory goes around the clock).

author: kwass
author_rank: Frequent Contributor
timestamp: October 09, 2013, 02:14:42 pm
content: Hi Grego,Thank you for that overview!I hear a lot of fan noise in your overview video can you tell me how much of that is coming from the SDG5082 vs the rest of your test equipment?Thanks,Kwass

author: grego
author_rank: Frequent Contributor
timestamp: October 09, 2013, 02:34:15 pm
content: You can hear the 5082 but to be honest the 53181 freq counter and the scope. Don't get me wrong, you can hear it but it's not horrible.I'm used to fan noise (I'm a network engineer by trade) so as long as it's not really obnoxious I tune it all out. Besides, I normally have music playing when I'm poking at the bench anyway.