What is this blue paint on old TO-92 Motorola parts?? - diyAudio
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Old 30th December 2012, 05:14 AM   #1
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Default What is this blue paint on old TO-92 Motorola parts??

Is it a relabled or a fake part?
Any one knows the answer..?
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File Type: jpg Mot painted blue.jpg (315.1 KB, 203 views)

Last edited by BenY; 30th December 2012 at 05:23 AM.
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Old 30th December 2012, 05:58 AM   #2
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Join Date: Sep 2007
I have seen this color of transistor before, I don't think they are fake.


Seems to be that they are matched types, or high tolerance/spec types.

High Jens,
I haven't found a trace of BF311 in my database, numbers start with
Regarding the blue paint, all I can tell you is, that I have some
old Tektronix oscilloscope boards, which are full of rare marked
transistors, blue painted Motorola signed, but numbers you will
never find anywhere. Seem common stuff.
I guess those are selected and tested items, but who would know.
Don't take this as fact though, its just somebody elses conjecture.
diyaudio is against your rights. I do not have the right to be forgotten and after asking the issue has been ignored, therefore I'm leaving (peacefully) for this reason. I stand up for my rights. So long and thanks for all the Fish

Last edited by freax; 30th December 2012 at 06:02 AM.
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Old 30th December 2012, 06:20 AM   #3
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I can at least say for sure Motorola did indeed paint their parts like that over a decade ago (maybe 2)... back when someone may have cared about unaided eye component identification.
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Old 30th December 2012, 01:44 PM   #4
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Yes, Philips did the same with their TO92 parts. When laser marking was introduced, clearer results were obtained by burning away the paint, giving dark blue or black lettering on a light (silver-blue) body. I don't think that had anything to do with quality levels - other than to identify their S.E. Asian production.

Last edited by Ian Finch; 30th December 2012 at 01:47 PM.
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Old 30th December 2012, 02:34 PM   #5
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I've got 100's of them and they are not fakes.
"Condemnation without Examination is Prejudice"
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Old 31st December 2012, 12:45 PM   #6
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In other words..

These are the standard type BJT`s of their time, nothing special about the metalic blue color marking.

Thank you all..
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