2N2222 Zener noise

Am 28.11.2010 02:09, schrieb Michael A. Terrell:

My computer is ok, and my barrier to killing someone is probably higher than yours.

That probably should read: "I am not a mad scientist, I'm just mad!!!11eleven1!!"

Gerhard

transistors

Yeah, a DVM, a few resistors, an old wall-wart power suply, and a few assorted transistors might cut into your palate educating budget.

John

I do! And charge for it!

We have reels of them. The slow gumdrop transistors cost a few cents. Pretty impressive RF parts cost $0.25 to 0.75 typically. Way, way down in the noise, so to speak.

It would be interesting to try a microwave transistor E-B zener as a super-wideband noise generator. Most official, expensive noise diodes are more in the 10 volt range.

John

Am 28.11.2010 02:58, schrieb John Larkin:

Have done that with a BFR93 / 96. Was completely flat to at least

2.5 GHz. Could not test more at the Weinheim ham meeting. Now, I'v got a calibrated Agilent noise source to 26 Ghz, so it's no longer interesting for me except as a built-in self test.

Gerhard

Not if you know how/where to dumpster-dive. ;-)

Cheers! Rich

Yawn.

Why would I use gibberish, I'm not European. I don't know why, but Europeans get all bent out of shape over sig files.

--
For the last time:  I am not a mad scientist, I'm just a very ticked off
scientist!!!

I don't suppose there's an ebay equivalent in the Netherlands. Or a Harbor Freight Salvage. It's amazing what you can get on ebay these days.

One of the guys here bought a spectrum analyzer on ebay, and we received it and shipped it to him in Italy.

John

On a sunny day (Sat, 27 Nov 2010 16:35:06 -0800 (PST)) it happened Bill Sloman wrote in :

This can be done with a 5 Euro meter, a 1 cent resistor, and a 2 Euro battery. if you have no money for the battery, use the one in the meter, and subtract (simple math is free).

I bought 20 BC557B transistors for 1 Euro last week, that is retail. Want the address?

Somebody said here something like: Engineering is the art of making new things from the things you have. That does not have to be expensive. But OK you will need a soldering iron, brain, solder, well... I guess we will have to wait then.

How did you connect the base winding?

There's some scope to tweak the limiting resistor in the base circuit to tame the output without incurring as much loss as a dropper resistor in the Vcc line.

Excessive output voltage can be turned to advantage by allowing enough headroom for a constant current circuit - much more stable noise source.

If you use a JFET constant current generator you can include LCR in series with the current setting resistor to tailor the noise response.

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So you don't question what you were taught - for fear of being declared a heretic and burnt at the stake. Unfortunately it seems that your edcuaton, or at least what you now remember of it, was woefully inadequate.

You'd like to think so. But before you tell me to check my references again, you should remind yourself that you didn't post any references and got your facts wrong.

ode is in series with the zener stabilizes the effects between the two.

nse is deleted..

It is "non-sense" because it conflicts with what Jamie thinks he remembers. Pity about that. Not only has he made an idiot of himself in public, but he reveals that he is too cognitively damaged to recognise that he has screwed up.

-- Bill Sloman, Nijmegen

Easy solution - bend the collector lead till it breaks off.

Implanted emitters produce high fT, but low reverse Vbe _rating_. I'm not sure they actually breakdown at 2V, but I know that migration and degradation begin there. ...Jim Thompson

--
| James E.Thompson, CTO                            |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
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I love to cook with wine.     Sometimes I even put it in the food.

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I got my access to that material before it was available over the internet as .pdf files. I just posted URLs so that yu ca=3Dould take another look at stuff that you shouldn't have forgotten.

But you can't remember much about any of it. This could be Alzheimer's which we can't do much about, or a series of small strokes, which could be helped by more careful control of blood pressure - you should talk to your doctor.

..

Sure you did. You just can't remember that any more.

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Wrong again. And the sort of brain damage that goes with loss of long term memory can also damage the victims social skills, making them more likely to express aggressive and unpleasant ideas, so you really do need to talk to your doctor.

-- Bill Sloman, Nijmegen

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The DVM I've got, though it is old and a bit temperamental,and I've got a handful of wallwarts, some of them offering a range of output voltages. The resistors I could buy down-town, from the local hobby shop, but I'd be surprised if they stocked broad-band transistors. I've paid, and continue paying, to have a business name (Sophia Electronica) registered with the local chamber of commerce, which means that I can, in principle, buy stuff from Farnell in the Netherlands, but there is a hefty minimium order charge. I will soon need some more lithium-manganese 9V PP3 cells for the smoke detectors (which I can only get from Farnell) but while the last lot went in some ten years ago the smoke detectors haven't yet told me that their batteries need replacing.

-- Bill Sloman, Nijmegen

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Sure. E-mail it to me. The BC557 - ft 100MHz - isn't a broad-band transistor, but the right sort of hobby-supplier - one with ham-radio- oriented customers - should have the BFR92 and BFT92 in stock.

The soldering iron and solder I've got, along with the side-cutters and the needle-nosed pliers. There's even some hook-up wire around somewhere. No prototyping board, but for this job a bird's nest would work fine.

-- Bill Sloman, Nijmegen

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There's a reason for this, that I laid out in the second post in this thread. Avalanche breakdown is noisier than quantum mechanical tunnelling (the Zener mechanism). With avalanche breakdown, you have not only the shot noise from the separate charge carriers making their independent way through the device but you also have the statistical uncertainty in the avalanche multiplication process, where every charge carrier needs to generate at least one pair of new charge carriers as it makes its way through the junction.

-- Bill Sloman, Nijmegen

transistors

It shocks me that you'd need official permission to buy electronic parts, or that there would be a big min order. Where's the social benefit in that? How are kids supposed to play with electronics if they can't get parts?

What constituency is all this pandering to?

John

tage?

You can amplifiy the shot noise of a forward biased diode. (Or light on a photodiode)

George H.

On a sunny day (Sun, 28 Nov 2010 08:21:05 -0800 (PST)) it happened Bill Sloman wrote in :

Check your email.