C639 is a BC639 NPN transistor?

[brunofunchas]

Hello,

I have a transistor with c639 marked on the body. I have seen on the internet and it indicates me that is a NPN transistor BC639, but when I measured it with my Peak Atlas DCA it says that is a FET transistor!
Can anyone confirm that even thought it indicates a FET it is really a NPN transistor?

Thanks,
Bruno

 

[schmitt trigger]

Does it indicate JFET or MOSFET? N or P channel?

I've seen Japanese transistors like to abbreviate the part numbers that way.
Thus a C639 would be a 2SC639.

I own a Peak Atlas instrument myself (for close to 10 years) and it has always accurately identified all devices. You have to calibrate it and load the latest firmware from time to time.

The only ones which it struggles with, are germanium transistors.

 

[albbg]

You can check it with an analog tester or a digital multimeter selecting the diode measurement.
Just verify the presence of the two junction b-c and b-e: in this case it's a bipolar transistor. Otherwise is a fet or a broken bipolar.

It's simple. See: https://www.antimath.info/electro/how-to-test-a-bipolar-transistor/

You can do the same with the DMM. In this case the meaning of red and black probes are exchanged.

 

[brunofunchas]

Hello!

In fact it was a NPN transistor since I came across another one with the same marking. Thanks fot the input on testing germanium transistor. I haven't seen them yet on a board!