scopes [was: how to troubleshoot? ...]

[Synthusiast]

> All this talk about multiple inputs on scopes got me thinking about
> something I built to use with my scope way back in the 70s when I was
still
> in 'lectronics school.  It is a transistor checker.  It hooks to both vert
> and horiz scope inputs and displays bent lines on the scope to define each
> junction.  Base to emitter junctions display a line with two 90 degree
bends
> on opposite directions.  Connecting E to C or B to C gives a line with a
> single 90 degree bend.  So, I dug it out of the junk, hooked it up to my
> scope and yes, it still does the same thing it did.  I remember checking a
> lot of transistors with this thing in the 70s when my supply for projects
> was whatever I could get my hands on.
>
> I have no idea where I got the plans or idea for the circuit.  Perhaps
from
> popular electronics or something.  It has a selector for in and out of
> circuit testing.  There is not much to it.  it contains a AC 120 / 6.3
volt
> transformer, a couple of resistors and switches, and that is it.  Anyone
> remember such a "test" circuit or have any opinions about its usefulness.
I
> remember it helped me sort a lot of transistors in to the "good" and "bad"
> piles.  If nothing else, you can identify the leads on an unmarked
> transistor.
>
> Larry Hendry
> (still trying to remember half of that stuff I learned back then)

My 10-year-old Hameg scope has a feature called 'component tester' which
matches the description you give. I never used it tho. The feature is still
implemented on newer Hameg models.

Cheers,
Synthusiast


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