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Robert Baer
Guest

Tue May 05, 2020 12:45 am   



John Larkin wrote:
Quote:
On Mon, 4 May 2020 12:40:49 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

jlarkin_at_highlandsniptechnology.com wrote:
On Sat, 2 May 2020 18:22:52 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

Mine quit - no vertical output.

Ideas? quotes? Etc?

Thanks.

What do you use a curve tracer for?



Part matching, spec conformance/non-conformance, check off-datasheet
specs, etc

Matching soulds iffy, on an analog oscilloscope curve tracer. Better
to design so that any data-sheet-conforming parts work.



On some of my designs, the part datasheet has no spec or a
non-meaningful value.
For example, there is no bipolar transistor datasheet spec for the
E-B junction zener voltage; "5V max" if at all.
I dare you to find a bipolar with a 6.2V zener breakdown by using the
datasheet.
Or 9.5V zener breakdown.
Tempco of that Vz?
So you gotta measure and best with curve tracer so you know how
sharp, if avalanches, etc.
And one can easily match within 10mV.


Guest

Tue May 05, 2020 1:45 am   



Robert Baer <robertbaer_at_localnet.com> wrote in
news:Sz1sG.273918$mf1.137923_at_fx45.iad:

Quote:
John Larkin wrote:
On Mon, 4 May 2020 12:40:49 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

jlarkin_at_highlandsniptechnology.com wrote:
On Sat, 2 May 2020 18:22:52 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

Mine quit - no vertical output.

Ideas? quotes? Etc?

Thanks.

What do you use a curve tracer for?



Part matching, spec conformance/non-conformance, check
off-datasheet
specs, etc

Matching soulds iffy, on an analog oscilloscope curve tracer.
Better to design so that any data-sheet-conforming parts work.



On some of my designs, the part datasheet has no spec or a
non-meaningful value.
For example, there is no bipolar transistor datasheet spec for
the
E-B junction zener voltage; "5V max" if at all.
I dare you to find a bipolar with a 6.2V zener breakdown by
using the
datasheet.
Or 9.5V zener breakdown.
Tempco of that Vz?
So you gotta measure and best with curve tracer so you know how
sharp, if avalanches, etc.
And one can easily match within 10mV.


Matching and culling transistor pairs (using a curve tracer) has
been around since before stereo amplifiers.

Robert Baer
Guest

Tue May 05, 2020 1:45 am   



Phil Hobbs wrote:
Quote:
On 2020-05-03 10:39, Winfield Hill wrote:
jlarkin_at_highlandsniptechnology.com wrote...

DecadentLinuxUserNumeroUno_at_decadence.org wrote:
jlarkin_at_highlandsniptechnology.com wrote in
Robert Baer wrote:

   Mine quit - no vertical output.

What do you use a curve tracer for?

  Testing transistors.

Do you use a curve tracer? I don't.

  They're pretty handy at times.  You get
  results a lot faster than with a SMU,
  but the SMU gives you precise answers.



And an HP 4145B gives you the best of both, with four SMUs.  (Assuming
you can keep the floppy drive working.)

Cheers

Phil Hobbs

Thanks!!!



Guest

Tue May 05, 2020 3:45 am   



On Saturday, May 2, 2020 at 9:59:10 PM UTC-4, Michael Terrell wrote:
Quote:
On Saturday, May 2, 2020 at 9:23:00 PM UTC-4, Robert Baer wrote:

Mine quit - no vertical output.

Ideas? quotes? Etc?

Join the old Tekscopes group. It moved from Yahoo to GroupsIO. The people who repair old Tektronix gear are there. Unlike Usenet, they do not tolerate foul language and insults, so some of the people on this group would be banned in a hurry. Some members offer kits to make extenders for the 7000 series of scopes.

https://groups.io/g/TekScopes/topics

http://w140.com/tekwiki/wiki/Main_Page has links to places where you can download manuals.


Ditto - been hanging out in that group for years. Lots of SME's with real world experience. Interesting to hear stories from the ppl that did the design/fab/testing in the tek labs.
If you wanna know about common failure modes of tek scopes, where to find replacement parts, etc. that is the place to hang
J


Guest

Tue May 05, 2020 3:45 am   



On Mon, 4 May 2020 16:29:49 -0700, Robert Baer
<robertbaer_at_localnet.com> wrote:

Quote:
John Larkin wrote:
On Mon, 4 May 2020 12:40:49 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

jlarkin_at_highlandsniptechnology.com wrote:
On Sat, 2 May 2020 18:22:52 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

Mine quit - no vertical output.

Ideas? quotes? Etc?

Thanks.

What do you use a curve tracer for?



Part matching, spec conformance/non-conformance, check off-datasheet
specs, etc

Matching soulds iffy, on an analog oscilloscope curve tracer. Better
to design so that any data-sheet-conforming parts work.



On some of my designs, the part datasheet has no spec or a
non-meaningful value.
For example, there is no bipolar transistor datasheet spec for the
E-B junction zener voltage; "5V max" if at all.
I dare you to find a bipolar with a 6.2V zener breakdown by using the
datasheet.
Or 9.5V zener breakdown.
Tempco of that Vz?
So you gotta measure and best with curve tracer so you know how
sharp, if avalanches, etc.
And one can easily match within 10mV.


Can you read Vz and the tempco of Vz, to millivolts, off the screen of
an analog scope? I can do that easily on a DVM. I think the diode
range of my Fluke is 1 mA up to 10 volts.

If you use a be junction as a zener, you should be careful that it's
repeatable.

Some transistors are accidentally 6.2v "reference zeners" from
collector to emitter with the base open. But's that's probably not
suited to production.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

Robert Baer
Guest

Tue May 05, 2020 7:45 am   



jlarkin_at_highlandsniptechnology.com wrote:
Quote:
On Mon, 4 May 2020 16:29:49 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

John Larkin wrote:
On Mon, 4 May 2020 12:40:49 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

jlarkin_at_highlandsniptechnology.com wrote:
On Sat, 2 May 2020 18:22:52 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

Mine quit - no vertical output.

Ideas? quotes? Etc?

Thanks.

What do you use a curve tracer for?



Part matching, spec conformance/non-conformance, check off-datasheet
specs, etc

Matching soulds iffy, on an analog oscilloscope curve tracer. Better
to design so that any data-sheet-conforming parts work.



On some of my designs, the part datasheet has no spec or a
non-meaningful value.
For example, there is no bipolar transistor datasheet spec for the
E-B junction zener voltage; "5V max" if at all.
I dare you to find a bipolar with a 6.2V zener breakdown by using the
datasheet.
Or 9.5V zener breakdown.
Tempco of that Vz?
So you gotta measure and best with curve tracer so you know how
sharp, if avalanches, etc.
And one can easily match within 10mV.


Can you read Vz and the tempco of Vz, to millivolts, off the screen of
an analog scope? I can do that easily on a DVM. I think the diode
range of my Fluke is 1 mA up to 10 volts.

If you use a be junction as a zener, you should be careful that it's
repeatable.

Some transistors are accidentally 6.2v "reference zeners" from
collector to emitter with the base open. But's that's probably not
suited to production.



and..that open base makes it rather sensitive to package leakages,
as well as partly sensitive to external EMI.


Guest

Tue May 05, 2020 11:45 am   



On Mon, 4 May 2020 23:23:14 -0700, Robert Baer
<robertbaer_at_localnet.com> wrote:

Quote:
jlarkin_at_highlandsniptechnology.com wrote:
On Mon, 4 May 2020 16:29:49 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

John Larkin wrote:
On Mon, 4 May 2020 12:40:49 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

jlarkin_at_highlandsniptechnology.com wrote:
On Sat, 2 May 2020 18:22:52 -0700, Robert Baer
robertbaer_at_localnet.com> wrote:

Mine quit - no vertical output.

Ideas? quotes? Etc?

Thanks.

What do you use a curve tracer for?



Part matching, spec conformance/non-conformance, check off-datasheet
specs, etc

Matching soulds iffy, on an analog oscilloscope curve tracer. Better
to design so that any data-sheet-conforming parts work.



On some of my designs, the part datasheet has no spec or a
non-meaningful value.
For example, there is no bipolar transistor datasheet spec for the
E-B junction zener voltage; "5V max" if at all.
I dare you to find a bipolar with a 6.2V zener breakdown by using the
datasheet.
Or 9.5V zener breakdown.
Tempco of that Vz?
So you gotta measure and best with curve tracer so you know how
sharp, if avalanches, etc.
And one can easily match within 10mV.


Can you read Vz and the tempco of Vz, to millivolts, off the screen of
an analog scope? I can do that easily on a DVM. I think the diode
range of my Fluke is 1 mA up to 10 volts.

If you use a be junction as a zener, you should be careful that it's
repeatable.

Some transistors are accidentally 6.2v "reference zeners" from
collector to emitter with the base open. But's that's probably not
suited to production.



and..that open base makes it rather sensitive to package leakages,
as well as partly sensitive to external EMI.


Not really. The c-b junction is forward biased and b-e is zenering
(collector is negative for an NPN) so there's no transistor action.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard

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