For whatever it might be worth, I tried six variations of 2N3055 on a 577 that has had only enough repairs to keep it functioning.
The 3055's varied with a 3055H and a 3055HV mixed in with epitaxial and non-epitaxial 3055's, including an actual Tektronix 151-0140-?
All of the traces looked like what you would expect, and nothing like what Wolfgang is seeing.
The gain of the 3055's varied widely, with the 3055HV having the lowest gain as you might expect.
All of the above means absolutely nothing in this current discussion, but any discussion about my favorite curve tracer model needs to be followed and looked at.
tom jobe...
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On 11/23/2018 3:30 PM, Craig Sawyers wrote:
Here are some pictures I took with a 2N3055 at various step settings:
/g/TekScopes/album?id=79121
I'm not at all surprised - a 2N3055 is a power transistor with a very large junction area. So it has a
very high capacitance.
I'd have to look it up, but one of Tek's curve tracer manuals sets out a procedure to match the
looping with removing the transistor and putting a capacitor instead. When the capacitor looping
matches the transistor looping, the capacitor value is the same as Ccb of the transistor.
Craig
