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Old 3rd June 2001, 04:51 PM   #1
grataku is offline grataku  United States
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The problem has surfaced in february of this year when I got a mixed order of an old and of a newly arrived stock that were sold to me as Sanken brand transistors. The new stock did not have the brand name Sanken but was instead a look-alike with an unheard of brand that I can't recall. The Hfe rank stamped on the case was 96H and I did make a note of that. The only gain ranks listed on the datasheet for this transistor are O, Y, P, and G. All the transistors had a consistently low gain between 5 and 15. These low gain figures are way off the charts for that transistor, in fact, the minimum Hfe for a 2SC2922 should be between 30 and 60 for the "O" rank according to the datasheet. Given the large Hfe mismatch with the complementary PNP type that I had also purchased, 2SA1216, I had to return the product. I should point out that there were no problems with the old stock 2SC2922 and the 2SA1216, they both were the usual Sanken transistor I am used to seeing with all the correct specs.
Two weeks ago I noticed that MCM had run out of stock and subsequently re-stocked the 2SC2922 I tried to buy a sample of two transistors just to see if they acquired the correct type. The brand stamped on the case is now Sanken but the transistors are the same "bad" transistors I got last time. I recognized the way the number is stamped on the case, all numbers are more narrowly spaced compared to the usual labeling. The gain ranking is again 96H which according to Sanken should not even exist. These devices now show the "stellar" Hfe of 1.6 and 8.4!
I think that is someone is licensed to produce Sanken transistors and to market them with the Sanken brand name they should at least maintain the correct specs as for the original.

In the meantime I have a question: how bad is to use this transistor in a regulated power supply when on the negative branch there is a 2SA1216 with an Hfe of 125 ??




[Edited by grataku on 06-03-2001 at 12:53 PM]
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Old 3rd June 2001, 10:41 PM   #2
djk is offline djk
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http://www.edtn.com/story/biz/OEG20010216S0069-R http://www.sound.au.com/madashell.htm#counterfeit I have not had problems with MCM in the past.I have had problems with Dalbani http://www.dalbani.com/ In the case of Dalbani this has been going on for more than 10 years.I will never buy another semiconducor from Dalbani.They have shipped me counterfeit 2SD555, 2N3773, MJ15022. They made good on one batch of 2SD555 only after extreme pressure(I had to threaten legal action).I suggest you do not use the bad parts.I also suggest you forward this message to MCM and put the ball in their court.If they don't clean up this mess now it will cost them much more later when it bites them on their backside.
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Old 3rd June 2001, 11:12 PM   #3
grataku is offline grataku  United States
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I have already sent an email to both Allegromicro and MCM. I would have sent an email to Sanken.jp but in the good japanese corporate tradition there are NO contact infos.
To MCM defense I have to say that I had no problems returning the mechandise last time.
The fact is that I really need the right transistors and I don't have time to screw around, therefore I want to get to the bottom of this situation once and for all.
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Old 4th June 2001, 05:40 PM   #4
Jon T. is offline Jon T.  United States
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Counterfeit semiconductors is not an unheard of problem. Typically, the retail distributor may not even be aware of it. Rod Elliot has an article on his website about a similar problem with Motorola transistors in Australia.

I would hope that MCM makes good on it. Keep us posted.

-Jon
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Old 5th February 2003, 02:20 PM   #5
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Grataku,

was this by any chance either WEC or Mosspec?

Regards,

Eric
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Old 5th February 2003, 10:22 PM   #6
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I have bought a lot of parts from MCM, and I would be very suprised if they do not make good of the situation.
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