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Old 19th January 2013, 09:46 AM   #11
Mooly is offline Mooly  United Kingdom
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Lets keep it friendly. I read the posts (which I've now pulled) and I'm sure nothing was meant or insinuated.
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Old 19th January 2013, 09:49 AM   #12
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Quote:
Most fakes are rebadged lesser components .. If the case fits change the nummbers..
The evidence on cracking open a unique case style component like an MT200 Sanken is no....rebadging is not the activity. Due to absurdly thin single layer heat spreaders, tiny 20W die and poor bonding technique, those are deliberate manufactures with the intent to defraud. IOW Fakes!

Where do they come from? Probably even the same fab. that has tendered for or even manufactured similar components under contract.
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Old 19th January 2013, 09:53 AM   #13
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Quote:
Originally Posted by Ian Finch View Post
The evidence on cracking open a unique case style component like an MT200 Sanken is no....rebadging is not the activity. Due to absurdly thin single layer heat spreaders, tiny 20W die and poor bonding technique, those are deliberate manufactures with the intent to defraud. IOW Fakes!

Where do they come from? Probably even the same fab. that has tendered for or even manufactured similar components under contract.
This goes even further to show that the fakers will stop at nothing .. It is a shame we cannot pay the fakers with countefeit money..That said renumbering componets is a large part of the problem for more common cased components..
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Old 19th January 2013, 12:40 PM   #14
JMFahey is offline JMFahey  Argentina
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In English
Counterfeit Transistors

In Spanish.
Try to translate it because it shows some useful test systems, both destructive and non.
Transistores falsificados

This is google translate:
Poor "me Tarzan you Jane" translation, callas "capability" which is "capacitance" and so on, just read it with a very open mind, but is the best I've found so far.
Traductor de Google
Non destructive include measuring die capacitance (works quite often, because it relates to die size), Hfe/beta (very different from original), etc.
Yes, careful weighting would have worked on some cases, as in those which skimp on the heat spreader size. (or simply don't use it).

Destructive testing rules, of course, and it's what I do: just mount the m*thaf*cka' on a heat sink, with mica, grease, the works, and subject it to torture:
apply rail voltage from the real amp, (remember to fuse the +V rail with a 2 or 3A fuse) and set current to what the datasheet SOA curve says, usually between 1.8 and 3A.
Time how long it takes for an original to die , which can take from 15 minutes to hours.
Fakes often *explode* or crack, or simply short, taking from milliseconds to a couple minutes.
Sure way to separate the men from the boys.
Should I have said "drag queens"?
They show a crude way to do that (which gave me the idea), using 120V and a series bulb, but it's too uncontrolled.
YMMV
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Old 19th January 2013, 12:55 PM   #15
HighTec is offline HighTec  Croatia
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Quote:
Originally Posted by jasoneyes01 View Post
The easiest way to identify a fake transistor is to weigh them on a digital gram scale. Please post weights of any output devices that you come up with. I have weighed several varieties of GENUINE Sanken TO3P's.... and they weigh exactly 6 grams. I bought a couple suspected Sanken fakes on ebay from China and will post the weight when they arrive.
The only ones I trust on ebay is Electronics Salon and Audio Wind.

2SA1186 2SC2837 SANKEN Audio Power Transistor, x 2 items in Electronics-Salon store on eBay!
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Old 19th January 2013, 01:26 PM   #16
Bigun is offline Bigun  Canada
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The best options in my view are:

- don't buy from China, at all.
- don't buy from individuals in general unless the parts are recovered from brand name amps
- some retailers do spend some effort to avoid selling faces, I use DigiKey in U.S.
- avoid using 'boutique' parts, they are the most tempting for fakers
- use vacuum tubes
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Old 19th January 2013, 01:40 PM   #17
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The application for this machine says counterfeit device screening:
http://www.focalspot.com/pdf/Datasheet-Mini-V.pdf

X-Ray Source: 75kV, 33 micron, not so easy to DIY
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Old 19th January 2013, 01:45 PM   #18
HighTec is offline HighTec  Croatia
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Quote:
Originally Posted by Bigun View Post
- use vacuum tubes
They are also made in China.
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Old 19th January 2013, 02:48 PM   #19
JMFahey is offline JMFahey  Argentina
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Yes, same as *good* Fairchild/ST/you name it transistors
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Old 19th January 2013, 02:55 PM   #20
Bigun is offline Bigun  Canada
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Quote:
Originally Posted by HighTec View Post
They are also made in China.
yes, but you don't need an x-ray machine to see what you got
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