Dont rely on vbe or hFE measurements to determine if they are FAKES. It’s too easy to find junk transistor dies that will give reasonable readings. Much harder to fake capacitance, speed, and power capacity.
The other thing that will usually tell you is where they came from. The likelihood of getting a real one, new, is one in 6.02X10^23.
The other thing that will usually tell you is where they came from. The likelihood of getting a real one, new, is one in 6.02X10^23.
Ok, I understand that. I have 3 amplifiers that I want to make 1 or 2 out of. I am recapping and doing other upgrades. All of the amplifiers seem to be untouched by anyone. I just wanted to match the outputs. This is on NAD 2200's. On the one parts unit it had a couple of bad outputs and one of the other had 1 bad output. I removed all of them and wanted to redo the heatsink compound and insulators.
I trust PULLS from amplifiers, provided that other units in parallel with them were not shorted. When one in a parallel bank goes, they all go. I might keep survivors for “B” stock, but not use them for anything serious. Parts out of a ‘good’ channel would be treated as pulls from working equipment. I wouldn’t use them to repair somebody else’s stuff, but might use them in my own.
i always wondered where On Semi got those odd part numbers for the very commonly stocked MJL1302/3281. Trying to capitalize on Toshiba parts that no reputable distributor in USA would stock. I bought some "toshiba" transistors from mcmelectronics once, at least that was the datasheet they linked to. The parts came in made in China with some unsearchable logo on them.
There's MJL1302/3281, originally Motorola's version, now onsemi, which I think is a better package match to the 2SA1302/2SC3281, as well as NJW one's which have more slimline package (but still called TO-3P). I presume these are all legitimate second-source devices, cross-licensed. So they are the same device basically. The modern parts look to have some slight improvements (higher voltage etc).
I guess a key feature to test for is good flatness of current gain from 0.01A upto 5A. An area where, for instance, early devices like the 2N3055 are pretty woeful.
I guess a key feature to test for is good flatness of current gain from 0.01A upto 5A. An area where, for instance, early devices like the 2N3055 are pretty woeful.
Compatible, but not identical. They are actually bigger dies. The NJW0281/0302 are the closest physical match, but are no longer available in the larger TO-264 package (but they are in the other smaller packages).