Correct. I'm waiting for samples. However, not available in the ZIP7 package but the TO-71 package will probably fit the lay-out of my Borbely power amp.
The simplest test is a breakdown test. I seem to remember the die being squared up on originals. It's been more than thirty years since I had one of those oped up. Something doesn't look right about that one.
First test is to put some acetone or lacquer thinner on a Qtip and see if you can remove the lettering. If they're fake the ink will likely come off. This test is not full prof.
Do some electrical tests.
Thanks!
I used Qtip with acetone with a little hard on the lettering but it still remains.
So electrical tests next. Which one do I need to test on this bjt?
I would do a breakdown test. There is some disagreement as to whether this should be done with the base open or shorted to emitter. You will need some form of current limiting. A 1k resistor will do. Insert a current probe into the circuit and you can test for leakage at the same time. For an NPN connect the emitter to ground and place the 1k resistor in series with the collector. Apply a positive voltage to the 1k resistor and vary the voltage from 0 to 10V greater than the collector breakdown voltage. Verify your transistor becomes a zener diode at the voltage the data sheet specifies. If it breaks down early then you have a fake. You might see smoke from the resistor.
I wouldn't leave the base open, tie it to GND. Seems more dangerous to leave base floating. It's best to do this on a curve tracer which will limit the power delivered to the DUT. I guess a series resistor will do. What's the max Vce spec? Also don't you want to check the beta? A crappy transistor will likely have a low beta.
Edit: just looked up specs. 200v Vceo and Vcbo. hFE 40 min at 10mA Ic. I would say you should measure beta in the 60 to 80 range. The collector breakdown should be > 200v (which could a bit difficult to test).
Last edited:
hfe ~ 170 -> ok since it is grade E (100 - 200).
And you are right, V collector breakdown > 200V means it is different to test for me.
I concern about this trans because Sanyo seem usually use print with white text, not laser print like of me. My friend have a pair of used 2SC3117/2SA1249 from Sanyo, look the text on body like this pic.
And you are right, V collector breakdown > 200V means it is different to test for me.
I concern about this trans because Sanyo seem usually use print with white text, not laser print like of me. My friend have a pair of used 2SC3117/2SA1249 from Sanyo, look the text on body like this pic.
What year is the date code on those? 4J2.
The print look authentic. Try removing it with lacquer thinner.