| Author |
Message |
    
Stitches
| | Posted on Monday, December 29, 2003 - 9:08 am: | 
|
I bought some 2SC1969 transistors off the internet and when I checked them, they all showed to be "PNP" aren't they supposed to be "NPN"? or am I doing something wrong? I checked them on three different testers, and all show "PNP". Thanks |
Bruce
| | Posted on Monday, December 29, 2003 - 11:26 am: |
|
last i checked they were NPN somethings very wrong. |
Stitches
| | Posted on Monday, December 29, 2003 - 12:57 pm: |
|
Could there have been a bad lot of these things (if this happens) and I'm the lucky one that got some? |
Bigbob
| | Posted on Monday, December 29, 2003 - 7:14 pm: |
|
The last time I checked a bad npn it showed as pnp on my tester,junk. |
2600
| | Posted on Tuesday, December 30, 2003 - 2:03 am: |
|
Hmmm. Wonder if it's just a counterfeit?
Does it have the three-pointed Mitsubishi logo printed above the part and batch numbers? Compare its appearance to one that you know is legit, like the factory final in 40-channel radio. If it looks just a little wider, or the numbers have a different size or appearance, it's a counterfeit.
If it has had an original number scraped off it, and the "C1969" printed onto it, who knows what type number it was made to show? For that matter, if it says "2SC1969" it's for sure a fake. Mitsubishi leaves off the "2" and the "S" from the part number, and will have only the "C1969" portion of the part number actually printed on it.
Never have seen a counterfeit 2SC1969. MRF477 and 2SC1307 have both been widely counterfeited since they were discontinued. That alone is what makes me suspicious.
73 |
Bruce
| | Posted on Tuesday, December 30, 2003 - 2:10 am: |
|
Stitches
can you lay one on your scanner and send the photo to me i would like to see the markings
wa4gch@yahoo.com |
Stitches
| | Posted on Tuesday, December 30, 2003 - 8:50 am: |
|
2600:
The Transistors do have the Mitsubishi logo on them as well as the number "C1969" and not "2SC1969".
Bruce:
I'll eMail you ok? |
2600
| | Posted on Tuesday, December 30, 2003 - 1:22 pm: |
|
Ya got me beat. The 2SC1969 was in production for almost 25 years. That's about five lifetimes for most electronic parts. As a result, the immense volume of production made the quality of a new, unused part about as high as it gets. Haven't seen a new one that's defective in over 20 years.
Sure hope I don't end up with any "backwards" 1969s.
73 |
Stitches
| | Posted on Wednesday, December 31, 2003 - 6:56 pm: |
|
I've sent these back to the person I bought them from for exchange for another batch, I have other "C1969" transistors that show "npn" so I will post here what comes back ok? |
2600
| | Posted on Saturday, January 03, 2004 - 5:18 am: |
|
Hmmm. That, and the identity of the seller, maybe? At least you know your tester is okay.
73 |
Bruce
| | Posted on Saturday, January 03, 2004 - 2:02 pm: |
|
i checked the sample Stiches sent
HFE=13 ( at what ever frequency my tester is happy at )
NO DOUBT NPN
The 1969 i got from stiches is correct |
Stitches
| | Posted on Saturday, January 03, 2004 - 2:28 pm: |
|
Hmmmm......it did show up as pnp on my tester, but what would cause this to happen when some others I have do show up as npn? I'm feeling more like an idiot, should have kept my mouth shut. |
Stitches
| | Posted on Saturday, January 03, 2004 - 6:05 pm: |
|
Well.....had some good e-mail chat with Bruce about all this and I got some good sound advice too. one is that not all testers are fool proof.As well some might have problems with some npn transistors, I apperantly seem to have such a tester. He had also explaind a few other small things that made a lot of sense to me. So I have come to the conclusion that I will slow down and take my time with this stuff. Thanks Bruce.
Now all I have to do is wait for the guy I sent these back to for exchange to yell at me, oh well.......a fella never stops learning right? |
409
| | Posted on Sunday, January 04, 2004 - 1:55 am: |
|
Use an ohm meter instead of a transistor tester and you can be sure of the polarity. |
|
