Unusual functions of cheap parts

Uh, real Labskaus doesn't contain fish. And the picture is unappetizing.

Oliver

--
Oliver Betz, Muenchen (oliverbetz.de)

You said it. "Um, do I eat this, or did I"

Cheers,

Phil Hobbs

During my time in the german military, I had some courses of instruction on a base near Hamburg. One day they served Labskaus in the staff canteen there. That stuff looked just like that on the wiki photo. This was the event when I learned why they had roller blinds made of solid steel between kitchen and refectory. One of the comrades said: 'I won't eat this. That's food for pigs!' And he threw his dish into the kitchen. Most others followed. The officer of the guard, whom the cooks called after closing the roller blinds, had to draw his gun and shoot in the ceiling to calm the riot down. Since I had been near the end of the queue, I had no opportunity to try this Labskaus. I still don't know what it does taste of.

Best regards, Günther

Citizens of Liverpool are called 'Scousers' (when they aren't called worse), this derived from the local delicacy lobscouse. Corned beef stew with chips in it.

Paul Burke

A step-recovery ("snap") diode works on the principle of stored charge in the diode. During the forward biased half of the AC waveform, the diode is a very low impedance and it stores excess charge; during the reverse biased half of the waveform, the diode remains a low impedance until the stored charge is depleted, at which time the diode "snaps" into high impedance. This snap acts much like a spark-gap transmitter, in that a tremendous number of higher order harmonics are generated. In general (and there are ways to enhance this), the power available from any harmonic is around 1/n * Pin, where n is the order of the harmonic and Pin is the RF power input to the diode.

Biasing the diode simply varies the point on the reverse cycle of the AC waveform where the diode snaps. For maximum power, you try to get the diode to snap at the peak of the waveform. However, by varying the diode bias, you can get it to snap before or after the peak of the waveform. Generally you can get it to snap plus or minus about 30 degrees about the peak before the snap action degrades.

60 degrees of phase shift is nothing to talk about unless you are working with the 10th harmonic, which means a phase shift of 600 degrees. Now you've got something to work with.

Jim

Looks a lot like ordinary corned beef hash to me, if a little less coarsely chopped.

But I wonder why they serve it with one of these?

;-) Rich

National Semi's (now Fairchild) 2n5771 was a gold-doped PNP. ft>=850MHz. For avalanche mode one might try the lower-Vce-rated PN3640 (12v), or PN3639 (6v).

I might even have notes on this. I tested/compared various BJTs in avalanche mode some years ago, trying to find the "best." ISTR picking the 2n2369, both because it was fast, and because it avalanched reliably where other types wouldn't.

James Arthur

Hi, James,

Interestingly, the best avalanchers aren't usually super-fast transistors, but old klunky things. The Zetex avalanche transistors have lowish Ft's and are made in Russia, maybe on an old process.

John

You could also serve with one of these:

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
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Howdy John, I was unclear: by "...it was fast..." I meant the 2n2369 was one of the devices with the fastest avalanche edges.

Digging through some of my notes, I don't see the BJT comparison, but a 2n2222 biased to +100Vce, banged / triggered by a 74HC-series gate, gave synchronous 750pS risetime pulses. Not very impressive, really, though good for higher-power stuff than I needed.

Interestingly, I found a 74AC00 driving an MPS2369 was faster & less trouble: 360pS fall (turn on) time, & 570pS rise (turn off) time, and no nasty high voltage supplies. It was possibly even a little faster than measured--at 360pS I was pushing my poor little 7S14 1-GHz sampling plug-in pretty hard.

Best, James

Hi Jim -

And on what delay timescale it works?

regards - Henry

"RST Engineering" schrieb im Newsbeitrag news: snipped-for-privacy@corp.supernews.com...

BA682.

From a cursory search, it looks like it'd be kinda hard to find one these days. ;-)

Cheers! Rich

He looks like this these days:

Best regards, Spehro Pefhany

--
"it\'s the network..."                          "The Journey is the reward"
speff@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com

Well, then the cook is to blame, not Labskaus per se. Go to Hamburg and visit the "Old Commercial Room". I guess they make still delicious Labskaus.

Oliver

--
Oliver Betz, Muenchen (oliverbetz.de)

That was a high-frequency part for the time, spec'd at 1200MHz...

An old Raytheon datasheet says the 2N2894 was doped with platinum.

BTW -- in AoE, we list the 2n5771 as a PNP complement to the NPN 2n5769, both 15V plastic versions of older metal-can parts.

--
 Thanks,
    - Win

the problem is, that it is an rf-transistor and can't be driven at

30V/0.2A, I found a complementary in an old table KTT, the 2N2894A, but it also has max. 12V, so I find no other than the 2N3906.

If I simulate with the 2N3906, the frequency response is not worse than with the 2N2894A.

mfg. Winfried

I was thinking of the "bismark roll", which I had thought was some kind of jelly donut, or "bismark donut", which would be like a jelly roll.

But I can't find a single reference to the thing except at the wikipedia disambiguator page, and all it has is the blurb, something like what I said.

Oh, well. :-)

Thanks! Rich

Is there a known figure of merit that would help select devices types for fast avalanche breakdown?

--
newell

[snip]

Thanks for tracking that down, Win! Gold in a PNP was certainly troubling my ancient remembrance of semiconductor chemistry.

...Jim Thompson

--
|  James E.Thompson, P.E.                           |    mens     |
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I love to cook with wine.      Sometimes I even put it in the food.