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wrote:
My first question is: does anyone have a cross reference for these MA/ME
transistors? Are those a kind of military markings?
Second question: almost all ME4101 have a junction voltage drop around 0.8V
but one of them shows a bit more than 1V drop on both BE and BC junctions
(it's NPN). Can I assume this one must be bad?
Any other hint and information is welcome.

I removed the suspicious one and put in my curve tracer. Indeed it shows
excessive VCEsat at already 5-10mA, I compared the curve to a bunch of
random BC147/8 that I had around (same era, should be very similar).
The BCs have almost straight saturation line, while this particular ME4101
start to sag towards 0.5V and more already at the 5mA level of Ic.
I'm sure it's marginal even for a 1970's transistor.
I didn't remove another ME4101 but bought a bunch of them (advertised as
NOS), so I'll have fun with the curve tracer once they arrive.

Frank