Author Topic: Calibrable el cheapo sig gens  (Read 505 times)

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Offline coromonadalixTopic starter

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Calibrable el cheapo sig gens
« on: November 12, 2024, 11:54:34 am »
hi

is there some cheap signal generators who's their calibrations procedures are known in the wild ...

I know  we have Siglents Rigols Fluke Waveteks, Uni-t  and  others..   and can be sent to cal labs


But i 'm more curious about the low end ones,  Juntek, Feeltech,  the ones based on fpga / r2r  technology

mostly to calibrate their main osc / time base frequency if it is possible


If you have some in minds   do tell   i'm all ears 

thks
 

Offline Aldo22

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Re: Calibrable el cheapo sig gens
« Reply #1 on: November 12, 2024, 12:27:35 pm »
What exactly is the purpose?
I have the super cheap FY3224s and the frequency can't get any more accurate than it is with this device.
The amplitude settings are somewhat inaccurate.
In the attached screenshot 500.000Hz.
« Last Edit: November 12, 2024, 12:29:13 pm by Aldo22 »
 
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Offline nctnico

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Re: Calibrable el cheapo sig gens
« Reply #2 on: November 12, 2024, 12:40:50 pm »
Calibration is not about precission, it is about determining whether the device is still within specifications (tolerance limits). Having the calibration done by a certified lab, gives you a traceable calibration and thus some assurance that the measurements made using the device really are within tolerance limits.

Things get hairy though when a device isn't within specs (=failed calibration) as this means that every measurement done between previous (good) calibration and the current (failed) calibration is suspect and needs to be re-done using a device which is within specs.

I'm not sure whether it is worthwhile to send a $50 generator to a cal lab. The price for the calibration will likely be a multiple of the price of the generator itself.
« Last Edit: November 12, 2024, 12:43:18 pm by nctnico »
There are small lies, big lies and then there is what is on the screen of your oscilloscope.
 
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Offline coromonadalixTopic starter

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Re: Calibrable el cheapo sig gens
« Reply #3 on: November 12, 2024, 01:09:30 pm »
The purposes is :   avoid sending or try sending  theses cheapos  to cal lab

And be extorted 160$ CAD for theses non calibrable Juntek jds2900  we have bought,  we bought them  just to help do things fast, under no certifications, field tests  under no precision / certifications

But we have intestinal fights,   where i say:  do not send theses !%%   and they insist to make them certified, certified in what ???


Now we have bought  few Rigols and lots of Siglent stuff,  3x  sdg 1000x,   3x ssg3000x,    scopes, spectrums,  etc ....  now more than enough to have certifiable equipment, and references ... if needed,  They don't go in the fields.

But the fight over theses 100$  "things"     ....  that's why i want to know cheap models who can be corrected in some ways if they are out of specs

I know not to expect miracles out of theses things,  mostly checkups (This is easy  loll, and happy with this)

thks
« Last Edit: November 12, 2024, 01:11:31 pm by coromonadalix »
 

Offline Aldo22

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Re: Calibrable el cheapo sig gens
« Reply #4 on: November 12, 2024, 01:32:26 pm »
I've had my FY3224s for 16 months now and the accuracy is better than the precision.
I mean, I can adjust it in 10mHz steps, but it is accurate to 1mHz (says the oscilloscope).
What do you want to calibrate here, what accuracy do you need?
It's $50. if one day it's not accurate enough, I'll order a new one, because all the other options are probably more expensive.
I'm not worried about that.

« Last Edit: November 12, 2024, 01:35:42 pm by Aldo22 »
 

Offline Aldo22

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Re: Calibrable el cheapo sig gens
« Reply #5 on: November 12, 2024, 01:42:23 pm »
I remember now, FY3200s has an option. See attachment.
I've never used it.
 
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Offline MarkF

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Re: Calibrable el cheapo sig gens
« Reply #6 on: November 12, 2024, 02:14:04 pm »
The purposes is :   avoid sending or try sending  theses cheapos  to cal lab

And be extorted 160$ CAD for theses non calibrable Juntek jds2900  we have bought,  we bought them  just to help do things fast, under no certifications, field tests  under no precision / certifications

But we have intestinal fights,   where i say:  do not send theses !%%   and they insist to make them certified, certified in what ???


Now we have bought  few Rigols and lots of Siglent stuff,  3x  sdg 1000x,   3x ssg3000x,    scopes, spectrums,  etc ....  now more than enough to have certifiable equipment, and references ... if needed,  They don't go in the fields.

But the fight over theses 100$  "things"     ....  that's why i want to know cheap models who can be corrected in some ways if they are out of specs

I know not to expect miracles out of theses things,  mostly checkups (This is easy  loll, and happy with this)

thks

It seems to me that if "Management" insists on all your test equipment being calibrated, it would be better off getting rid of all the cheap stuff and use the money saved on their calibration to buy more of your better equipment that has a defined calibration path.

A perfect excuse to upgrade...   :-DD
 
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Online tszaboo

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Re: Calibrable el cheapo sig gens
« Reply #7 on: November 12, 2024, 03:46:45 pm »
The purposes is :   avoid sending or try sending  theses cheapos  to cal lab
You have a quality manager who wants to calibrate everything.
I see two options, you can either slap an "Uncalibrated" label on them. Or a "Scrapped label" on them and take them home for a nominal fee. And try not buying equipment without a cal certificate in the future.
I certainly prefer this situation over the situation where I have to fight to get essential test gear calibrated.
 

Offline coromonadalixTopic starter

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Re: Calibrable el cheapo sig gens
« Reply #8 on: November 12, 2024, 04:19:55 pm »
thks  i'm trying to get thoses  ......  far awayyyyy

but i was trying to find some  for easy portability, and be able to certify them   

witch sound at some point not plausible

i had in mind some of the uni-t   models    have to see if we can certifiy / calibrate them if needed

the Junteks jds2900  can not support shorts or very low impedance for long,  smd in them  burns,  dont know for others   low end ones

the TTi  Rigols Siglent   are okay, (half rack width)  but portability :(
 

Offline Aldo22

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Re: Calibrable el cheapo sig gens
« Reply #9 on: November 12, 2024, 04:26:28 pm »
the Junteks jds2900  can not support shorts or very low impedance for long,  smd in them  burns,  dont know for others   low end ones

FY3200 manual says: "All channels can work more than 60 seconds when the load is short-circuited."
 


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