My Transistors, original or copy?

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I recognize transistor on the right side,it is ON.I had some 2BC556B(ON) from farnell and because that I know.

Here is picture of 2SC3117 and 2SA1249.I bought them in my country(Serbia) and I think that they are original.I paid 0.69euro for one piece.
Hfe is from 220-260,Ube(Uce=(-)6V,Ie=(-)11mA) is 0.6V for NPN and -0.602V for PNP.

Here is picture...Are they original?

An externally hosted image should be here but it was not working when we last tested it.
 
I bought a pair of AD149 (Germanium Power) transistors.

When I tested them out on a multimeter I found:
1) Junction voltage = 0.5 Volt. (B-E and B-C).
2) Gain 180. (datasheet specifies 30-100)
3) No measurable Leakage current. (C-E).

Based on this I think what I have is a Silicon transistor.

However, I bought them from an old established retailer and he assures me that he has sold these very same transistors to other people who have used them to repair old amps successfully.
I had to search long and hard to find these devices and I would very much like to use them.

I have a theory that there might have been a time when production of Germanium AD149s had ceased, but there was still demand for the devices, so someone marketed a Silicon equivalent.

What do you think ?
 
Hi ,i heard about a SOAR curve or something like that for test Tr's.does anyone have info or link about how i can do that ,and its can be done by a DIY? ....as many others i have the bad feel when a tr...puff...blow in normal operation and realize that is a fake one, can i test it "rude" before i replace ?thanks
 
i post a pic of "test" i been made to identify fakes...
 

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BEL-manufactured AD149s (red text) are most probably authentic NOS devices, while those marked Toshiba AD149 (red text) could be fakes. There's no reliable info on whether Toshiba ever produced TO-3 AD149s.

I have a pair of each in Bangalore, contact me offline if you want to buy them.
 
Hi Linuxguru,
These just have "AD149" in red text. Doesn't say BEL anywhere.

The point is, all the other germanium devices I found had a junction voltage of 0.1 V (measured on a multimeter) and significant leakage current (measurable on the same multimeter).

Can this be a Germanium device at all with a 0.5 V junction voltage ?
 
I haven't popped the case on any of my AD149s, mainly because they're still working and I might find a use for them as a low-dropping series regulator or some other non-audio application.

However, I'd say that the die size on your AD149 is generally about right, even if it looks very small. What is suspicious, however, is the way it has been attached to the backplate - there are untidy traces of bonding material all around. That would suggest a manual cottage-industry operation, not an automated manufacturing line - increasing the probability that it is indeed fake.
 
2SK389 - forgery

2SK389 - TO-92, three legs, from Matchaknob, NY.
I've got the last stock. Apparently, they have sent plenty of
them to unsespecting buyers. At least for the 2SJ109 they did
mention three legs in their catalog, but not for the 2SK389. What a surprise!
I have filed a complain with my credit card and sent the datasheet to the distributor (no response).
Better Business Bureau and Attorney General of NY can also be
informed, if necessary.
 
Go for it.

5 or 6 years ago, they advertised some NOS Toshiba TO-3's (can't remember the number). I bought a few as a test, and they were authentic. So I queued up the credit card and bought a couple hundred dollars worth and set them aside. When I finally got around to using them about 8 months later, I discovered about 3/4 of them were Chinese fakes. Much too late for my poor credit card...:hot:
 
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Joined 2004
Paid Member
Hi,
I can't stress this enough. You must buy your parts through normal and established vendors who are dealers for the part in question. Lately, a number of second source suppliers have appeared. Treat them as an unknown manufacturer and test some before committing to a large buy. Once you become familiar with that manufacturer (and they are acceptable!), just make sure you buy from their dealer network. Don't assume a second source part is identical until you prove it.

There are factories in China that are producing hard to get transistors. They may be legitimately trying to produce an equivalent part, but you really need to make sure in these cases. Watch for quality control variations.

I have bought parts from various small vendors, some on Eeekbay. Some of these are garbage and others have turned out to be the real deal. You just never know.

Some real uPA68H dual fets would be nice to find. However, if there are 100 pcs available I'd be real suspicious! You have to consider what is reasonable for a long discontinued part. The back story is going to be extremely important in these circumstances.

-Chris
 
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Joined 2004
Paid Member
Hi Glenn,
Yep, I just wanted to say something and I couldn't think of anything intelligent, so I posted here. :clown:

I'm sorry to hear you got, got. These vendors ought to know better. That's where the old jobber system worked well. You could see exactly what you were getting. That is unless the bag said "ECG". Fakes and remarks have been with us for a very, very long time. Even in the tube days. "Original Equipment" anyone? :angel:

-Chris

Edit: You have a nifty avatar. I like mine with a clip, but we are restricted to 10 or less. :( Well, it's not like you want to squeeze off more than one without ear defenders and glasses.