Techs: What's on your Shelf of Weird Things?

[CJT]

heating element?

Tuned cavity?

 

[Mark D. Zacharias]

I have a TIP-41 transistor that works perfectly until the package
exceeds ~90 degrees F. Then the B-E junction goes open. Let it cool,
and it works again. You can watch the junction open and close with
the heat from your fingers. I assume a defective wirebond to the die
is to blame.

I see LOTS of flat-packs do this.

Mark Z.

 

[m kinsler]

I see LOTS of flat-packs do this.

The best transistor story I ever heard was from Sam's predecessor Jack
Darr. There was an uncontrollable hum in a TV's sound that developed
when the case was removed. The sound altered volume when the
technician's hand was moved nearby. Turns out that an audio
transistor's black epoxy case wasn't black, but translucent brown; the
carbon black hadn't been mixed properly at the factory. The
transistor junction is light-sensitive, and the 120Hz flicker from the
shop's lamps was reaching it through the translucent epoxy case.

M Kinsler

 

[Allodoxaphobia]

Tuned cavity?

I was a'thinkin' some kind of gas ionization
probe/monitor/measure'er/counter thingy.

Jonesy

 

[Sam Goldwasser]

I was a'thinkin' some kind of gas ionization
probe/monitor/measure'er/counter thingy.

Hmmmm, but why the pointy legs?

http://repairfaq.cis.upenn.edu/Misc/sale/thing-2.jpg

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
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| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

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[Gary Tait]

OK, here's one:

http://repairfaq.cis.upenn.edu/Misc/sale/thing-1.jpg

Inside, are two nested cylinders that are electrically insulated from
the others, but attached to two of the pointy probes on the left via
the two middle flanges.

What is it?

Gas sensor?

You place a (somewhat hight) voltage on the terminals, ands as the
composition of the gas changes, so does its electrical properties, which
are senses by a circuit connected to the probes.

 

[bz]

OK, here's one:

http://repairfaq.cis.upenn.edu/Misc/sale/thing-1.jpg

Inside, are two nested cylinders that are electrically insulated from
the others, but attached to two of the pointy probes on the left via
the two middle flanges.

Vacuum capacitor? [when installed in a vacuum chamber], perhaps part of an
electrode assembly from a mass spectrometer of some kind.

Perhaps the inner cylinder is heated by current between a couple of the
pins and acts as an electron gun or acts to inject a sample(by heating it)
into an instrument.







--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

[email protected] remove ch100-5 to avoid spam trap

 

[Sam Goldwasser]

OK, here's one:

http://repairfaq.cis.upenn.edu/Misc/sale/thing-1.jpg

Inside, are two nested cylinders that are electrically insulated from
the others, but attached to two of the pointy probes on the left via
the two middle flanges.

Vacuum capacitor? [when installed in a vacuum chamber], perhaps part of an
electrode assembly from a mass spectrometer of some kind.

Perhaps the inner cylinder is heated by current between a couple of the
pins and acts as an electron gun or acts to inject a sample(by heating it)
into an instrument.

It would be kind of hard to seal it. You can't see it in the photo, but
there's a hole in the end of the outer cylinder, probably the others as
well. Those pointy legs must be to stick into something. But what?

--- sam | Sci.Electronics.Repair FAQ: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Sites: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: Anything sent to the email address in the message header above is
ignored unless my full name AND either lasers or electronics is included in the
subject line. Or, you can contact me via the Feedback Form in the FAQs.