There aren't any mysteries in P-N junction physics or chemistry, but most
hams don't know (or need to know) much about it. I've been reading the
thread here a bit and some of the stuff stated is rooted in mythology, but
it's been great reading. My old curve tracer removes a lot of guesswork,
and they're available surplus (not eBay!) for just a couple of hundred
dollars in working condx; more handy than a hipot tester since it gives you
a steady visual display of what the junction's really doing. You can get
out a $10 hair dryer and see the effect of heat, or a freeze mist spray and
see the effect of cold. Right there on the screen...cool stuff. -WB2WIK/6
> Oh yeah!! I forgot about those things. We had a Huntron Tracker that did
> that kind of graphic analysis of junction devices, caps, coils, etc. It
> was actually a pretty cool device.
>
> Joe,
> N3JI
>
> Steve Katz <stevek@jmr.com> wrote:
> Using an old Tek 575 curve tracer works, too. Those can deliver
> thousands of volts bias, and let you not only run a rectifier prospect
> into
> avalanche, but allow you to look at the breakdown characteristic to pick
> out
> only those devices that are stable in avalanche -- they last a lot longer
> (usually forever) than ones that jitter. -WB2WIK/6
>
>
> > >>
> > -- Put a 5 to 10 meg-ohm R in series with a uA meter in series with
> > the high-pot tester. Connect to the device under test (DUT) and slowly
> > increase V until a reverse current of c. 5uA flows. Stop increasing V
> > and record it. This is what going on in pic20 in the Class A amplifier
> > project on my Web site.
> > >
> > > cheerz, Joe
> > >
> > > Richard L. Measures, AG6K, 805.386.3734. www.somis.org
> > >
> >
> >
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