Author Topic: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x  (Read 132525 times)

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Offline babysitter

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #75 on: October 24, 2016, 04:03:02 pm »
If not too late, i will take 30 pcs too.
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Offline BravoV

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #76 on: October 24, 2016, 04:06:42 pm »
Me 20

Offline janode

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #77 on: October 24, 2016, 04:07:13 pm »
My bet is they simplt relabelled old stock transistors and sold them. Try them for gain, it might be a Germanium PNP transistor with a badge job.

I'm too young for germanium transistors  :-DD I measured Vf 0.7V so silicon. Vz ~5.6V @ 5mA. It would have been more fun to find out they were something weird rebadged, but no..
 

Offline Cerebus

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #78 on: October 24, 2016, 04:12:57 pm »
I'm too young for germanium transistors  :-DD I measured Vf 0.7V so silicon. Vz ~5.6V @ 5mA. It would have been more fun to find out they were something weird rebadged, but no..

I'm old enough to remember scraping the paint off the outside of glass encapsulated OC71s to convert them into phototransistors.  :(
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Online Echo88

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #79 on: October 24, 2016, 06:21:42 pm »
Can someone tell me, how all of you are gonna make use of the low noise while maintaing extremely low drift? Wouldnt it be more reasonable to just stick together a few LTZ1000 to get sqrt(n) noise reduction, while having a very low drift, backed by decades of experience?  ???
 

Offline Nuno_pt

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #80 on: October 24, 2016, 06:22:34 pm »
Update, just missing @BravoV since I can't see is flag.

For now:

383 for EU.
115 for US.
20 for Asia.


Let's see how many @zlymex was able to buy,  and then figure a way to split them if enough for all at same time, or we've to buy the rest on the second round.

For now also if put only 30 pieces for each one, base on the 300 units that @zlymex told.
« Last Edit: October 25, 2016, 07:41:25 am by Nuno_pt »
Nuno
CT2IRY
 

Offline Nuno_pt

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #81 on: October 24, 2016, 06:33:21 pm »
Can someone tell me, how all of you are gonna make use of the low noise while maintaing extremely low drift? Wouldnt it be more reasonable to just stick together a few LTZ1000 to get sqrt(n) noise reduction, while having a very low drift, backed by decades of experience?  ???

On the first page @zlymex show that the 2DW23x has lower noise then the LTZ, but what we'll see is the long time drift, if it's something like the LTZ with can be good since for let's say 4 modules it cost around $1 plus shipping, while the same 4 LTZ it's $200 plus shipping.

For me will be an experiment about long time drift.
Nuno
CT2IRY
 

Offline plesa

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #82 on: October 24, 2016, 06:36:32 pm »
Count me in, please. 30pcs (buy limit)
 

Offline TiN

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #83 on: October 24, 2016, 06:40:28 pm »
Subbed  :popcorn:
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Offline Galaxyrise

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #84 on: October 24, 2016, 09:04:47 pm »
I'd like to be in for 20.  Very much appreciate the efforts of those members making this possible, even if I'm in too late for this time around.
I am but an egg
 

Offline evb149

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #85 on: October 25, 2016, 01:41:15 am »
I couldn't get the translate to work for my browser on Taobao last night and I didn't see any indication of Shanghai 17th radio factory online by any searching that I thought could lead to something like a direct alibaba or ebay or tmall store of theirs if they had one.

So for the moment I will be content with whatever quantity is possible to make available in this small group purchase and if there is in the near future another another group buy with larger quantities I would probably still be interested in 100-200 additional pieces of the part discussed here.

If the noise is as good as has been suggested by others' experiences then that to me is good enough to be useful.  If the long term drift is also reasonably low then that is even better.  But for many applications just a somewhat stable but low noise and inexpensive source could be useful for short term measurements.  At 1/200th the cost of a LTZ1000 it would be tempting to use it for dozens of applications where I wouldn't use a much higher cost reference simply due to cost.
And if you need low noise and low drift you can always combine a stable reference with this low noise reference in the same system if you can correct for the drift of this reference via a digitally applied offset from the measured value of the stable reference.

 
 

Offline zlymex

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #86 on: October 25, 2016, 03:43:39 am »
I bought 9 bags, 450pcs(50pcs in a bag). I have to open at least one bag to check when arrived today or tomorrow.
The weight of one bag is 52.5g, so 9 bags is 473g. Plus package, it may exceed the 500g limit, so I may have to ship 400pcs.

I've just search "2DW232" and "Shanghai 17th Radio Factory"(in Chinese) and got 7 entries, all the sellers are in Shanghai.
The 1st is the one I bought(having bought 5 times), The 2nd have been bought 1 time.

I've once try to put Chinese here but it won't allowed by the forum, but here I try again for Shanghai 17th Radio Factory:
????????

Edit: the above two faces plus two "?" were in Chinese but showed incorrectly.
« Last Edit: October 25, 2016, 03:48:11 am by zlymex »
 
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Offline TiN

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #87 on: October 25, 2016, 03:46:57 am »
This forum does not support non-western symbols. Same with cyrillics :)
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Offline BravoV

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #88 on: October 25, 2016, 03:50:49 am »
Update, just missing @BravoV since I can't see is flag.

For now:

383 for EU.
115 for US.

Let's see how many @zlymex was able to buy,  and then figure a way to split them if enough for all at same time, or we've to buy the rest on the second round.

For now also if put only 30 pieces for each one, base on the 300 units that @zlymex told.

Check your PM.

Online blueskull

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #89 on: October 25, 2016, 04:02:39 am »
I've once try to put Chinese here but it won't allowed by the forum, but here I try again for Shanghai 17th Radio Factory:
????????

Put the search URL into a URL shortener, then post the shortened URL.
 

Offline VintageNut

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #90 on: October 25, 2016, 09:07:20 am »
Hello Zlymex

Can you ship 300 pcs to EU and 150 pcs to USA? There are more people in EU who want these parts.
working instruments :Keithley 260,261,2750,7708, 2000 (calibrated), 2015, 236, 237, 238, 147, 220,  Rigol DG1032  PAR Model 128 Lock-In amplifier, Fluke 332A, Gen Res 4107 KVD, 4107D KVD, Fluke 731B X2 (calibrated), Fluke 5450A (calibrated)
 

Offline Cerebus

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #91 on: October 25, 2016, 09:58:40 am »
I've once try to put Chinese here but it won't allowed by the forum, but here I try again for Shanghai 17th Radio Factory:
????????

Edit: the above two faces plus two "?" were in Chinese but showed incorrectly.

The forum software is weird. It manages character encodings correctly up to and including previewing your own comments but then seems to completely stuff the encoding when you actually post the message.

For example, I'll type "?" here, and what's in the quote marks as, I see them, is a Greek omega. I'll hit 'preview' and, it still looks like an omega to me, now I'll hit 'post' and, based on past experience, it'll turn into "?".

Editted to add: And sure enough, that's exactly what happened. It makes the 'preview' feature half useless.
Anybody got a syringe I can use to squeeze the magic smoke back into this?
 

Offline quarks

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #92 on: October 25, 2016, 10:54:05 am »
seems to be to late, but I would be interested to know if I can still join and buy 30 of it
 

Offline zlymex

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #93 on: October 25, 2016, 03:58:25 pm »
- Norminal zero-TC current ranges from 5mA to 15mA depending on types.
These 2DW23x series(2DW232, 2DW233, 2DW234, 2DW235) has been around for many year and ....

were you able to try the diff in noise between the xx2 (5mA) vs the xx5(12.5mA)?
Every device I tested follows the inverse square root rule
Noises were all similar at given current
Zero TC current are different among xx2
Zero TC current are the same between xx2 and xx5
 
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Offline zlymex

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #94 on: October 25, 2016, 04:08:25 pm »
Package arrived today, will test tomorrow.
 
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Offline janode

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #95 on: October 25, 2016, 04:21:00 pm »
Can someone tell me, how all of you are gonna make use of the low noise while maintaing extremely low drift? Wouldnt it be more reasonable to just stick together a few LTZ1000 to get sqrt(n) noise reduction, while having a very low drift, backed by decades of experience?  ???

While low noise and low drift enable many experiments, so does also low cost :) I guess most are hoping this offers a combination of low cost and low noise.
 

Offline evb149

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #96 on: October 26, 2016, 01:14:28 am »
Thank you very much, zlymex.  It looks good.  Good luck with your tests.
The package seems to have arrived very quickly to you.
 
Package arrived today, will test tomorrow.
 

Offline simon51

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #97 on: October 26, 2016, 03:37:28 am »
Package arrived today, will test tomorrow.
I also bought 50pcs 2DW232 from the same seller,looking forward your test methods and results. :clap:
 

Offline zlymex

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #98 on: October 26, 2016, 07:31:15 am »
Package arrived today, will test tomorrow.
I also bought 50pcs 2DW232 from the same seller,looking forward your test methods and results. :clap:

I've just finished testing 10, powered by three lithium cells in series(12.4V noise free) and series 1k precision resistor with the test zener to get about 6.3mA test current.


The terminal marked red(may be other color) is negative, center terminal is positive, the other terminal(connected to the case) open.

Because the noise is very small, and also the TC is not tuned, the device is very sensitive to air turbulence, I covered it with a lot of tissues (wrapped around the device and legs).

The result is positive, 9 is very typical but one is a bit above average. I plotted these on the original chart with added green dots. Some dots are overlapping.

I've packed 430pcs up and ready to ship to VintageNut/USA tomorrow.
« Last Edit: October 26, 2016, 07:33:59 am by zlymex »
 
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Offline VintageNut

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Re: Ultra Low Noise Reference 2DW232, 2DW233, 2DW23x
« Reply #99 on: October 26, 2016, 12:51:54 pm »
Hello Zlymex

Thank you for buying these parts for the Metrology community here.
I will coordinate with the other interested people to distribute the parts.
I think we should start a group buy thread and take that discussion off of this thread.

Please let me know if there is a way to compensate you for buying the parts. If you cannot receive an electronic payment, is there something you want to acquire from the USA that I can send to you via USPS/China Post that is the same value? Maybe something that is difficult for you to acquire in China but costs about the same as what you paid for these parts?

The science behind your personal metrology projects is impressive. Building your own microvolt DIY noise meter is one example. For sure, I will want some help on this thread building up a set of 4 references like the Fluke 732B .

best regards,

VintageNut
working instruments :Keithley 260,261,2750,7708, 2000 (calibrated), 2015, 236, 237, 238, 147, 220,  Rigol DG1032  PAR Model 128 Lock-In amplifier, Fluke 332A, Gen Res 4107 KVD, 4107D KVD, Fluke 731B X2 (calibrated), Fluke 5450A (calibrated)
 


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