proposal

Better yet, xor them into the insides of some long pseudo-random shift registers to make random giant state jumps.

One little FPGA could make hundreds of long LSFRs. Mush a dozen zeners into them. It woud bankrupt the CIA trying to break that.

I was thinking that a cheap FPGA could generate crypto-quality random numbers with no external parts. An RP2040 could too.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

There are two or three very-well-funded fusion energy startups now, that plan to use bar lasers to compress hydrogen pellets to fusion at maybe 10 Hz. Inertia, a spinoff of NIF, is one.

NIF has achieved over unity light-to-energy fusion, but they use flashtubes which are very inefficient at pumping their lasers. So their wall-plug efficiency is awful, and their shot rate is maybe

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

What's that in volts?

What amplifier did you use?

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

It's kinda fun when you run into one "in the wild" so to speak. :-) Ed

You can NEVER get more energy out of a spring than you put in compressing it!

No matter what divide by zero mamaticians and einstone say.

It is a job creation program for their parrots Ever new company startups looking for yet an other clueless investor. Governments pouring money in it too (ITER)

A chain reaction is like a spring hold together by some small clamp hit it end it will remove the clamp and it will jump, every now and then a clamp fails all by itself... now put enough of those clamped springs together and hit it or wait a little till the first clamp fails, that triggers a chain of expanding springs involving all .

What they call 'fusion' is trying to compress the springs again not even clamping those.

In real life, sure you can. Like a hydrogen bomb. Or a diesel engine.

Some people think a chance in a hundred is a good investment if the payout might be 10,000 : 1.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

About 7.75 microvolts RMS..

From memory it was most likely a TL082 and a TL084 - I ve put a copy of the circuit diagram at:

I see. I wasn't familiar with dBu. With a little effort, I think I could probably collect over a hundred dBxx units in use in one place or another. I use only a few.

Jeroen Belleman

Today, I do almost similar things with CorelDRAW! Much to the chagrin of some of the regulars in comp.lang.c and elsewhere who think open source is some magic sauce.

Alas, I do not have anything I'd consider /worthy of publication/, as I have only recently started to draw vectors somewhat seriously.

What do you use when you feel like drawing vectors? Xfig?

Berol Turquoise F on D-size vellum.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

The dB is such a useful concept that it crops up in all sorts of places but even people who use it regularly don't seem to be aware that it is a unit of power ratios ...and only power ratios ...and nothing else. To work out what those two power levels are, we may have to measure voltage and make certain assumptions.

In a 600-ohm circuit, there are mathematical short cuts we can take because the impedance is always the same but using the same shorcuts in a circuit with different impedances at different points can lead to stupid results. A FET can appear to have near infinity gain if you compare power in with power out and I have had long arguments with people who insisted that a transformer gave 20 dB of gain because the output voltage was higher than the input voltage.

The suffix is where the devilish detail occurs. That is how dB can be used as a measure of absolute values by referring it to some fixed quantity, such as 1 milliwatt, and specifying some measurement method, such as voltage. Hence the dBu = the ratio in dB between 1mW and the power which the voltage being measured would give if it were applied to a 600 ohm resistor.

Take a picture of your vectorscope:

Or from

Springs don't release more power than you put into compressing them.

Hydrogen fusion is compressing four hydrogen nuclei (H-1) hard enough that they transform into He-4, which does releases more power than you put into comnpressing the hydrogen hard enough to make it happen.

Albert Einstein did formalise the mass-energy equivalance in e=m.c^2 Where e is energy m is mass and c is the speed of light in a vacuum. Chose your own system of units to keep the dimensions right.

Jan Panteltje is too dim to follow Einstein's reasoning and finds it easier to think that he was wrong.

Am 25.09.26 um 16:56 schrieb john larkin:

Absolute noise levels of some LEDs: <

Preamp is 10 pairs of ADA4898-2 in parallel, 220 pV/rtHz in the flat part. The worse than 1/f noise rise towards low frequencies comes from the undersized input coupling capacitor. It must be much bigger than needed for the lower corner frequency since it must short the bias resistor noise through the low-impedance DUT. Scott Wurcer RIP, the father of AD797, AD825.. saw that immediately. I took 2 weeks longer.

Pics to the right: some regulators, then some Zeners/avalanche diodes.

No, Zeners are fine. In the pic, the BZX84 family the 2.7V is > 30 dB better than the 6V8. At 5 to 7V the avalanche effect has taken over. At 3V3 and 4V7 it starts to get worse and worse, noise-wise. Zener and Avalanche have different signs of TK. Somewhere near 6V they compensate each other.

In a case of scientific honesty, Prof. Zener sued the industry that they should not use his name for avalanche diodes. He won, but the ghost had already escaped the bottle.

I once used the BE junction of a BFR93A transistor as a noise head and had it measured at the Weinheim amateur radio meeting. It delivered 22 dB excess noise to > 2 GHz flat. Now, I have such a thing + 8970B: <

cheers, Gerhard

Hey, I did that too. I never used it in anger though. Shortly after I got an HP8591E with noise measurement option and an HP346B noise source. Even that noise source didn't see much use. Along the path to making quieter amplifiers, I switched to using an SMA terminator in LN2, and comparing it to another at room temperature.

As for random noise generation, did the OP state the purpose? There are so many interpretations of "noise".

Jeroen Belleman

That's $1000 per dB of excess noise.

John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics

In message <119qp7k$o9f4$ snipped-for-privacy@solani.org, Gerhard Hoffmann snipped-for-privacy@arcor.de writes

I did that at work in the 1970s. I only wanted 100KHz to about 15MHz. I used the BE of a BFY90 followed by a 733 and a two- pole two transistor Sallen Key. My supervisor got a bit sniffy about it. He said the noise wasn't Gaussian. It was good enough for what I wanted I've still got the little box I made.

I've used these in ham radio - noise bridges and one with a switch to check preamps.

Brian

CorelDRAW! has a built in tool for exactly this. I can do this locally.

I just don't want to. You see, tracing photographs, or something else, by hand trains the artist to draw. Pressing a button in CorelDRAW! is not drawing. It's pressing a button.

And pressing a button on someone else's website is also just pressing a button.

Ideally, I'd like to use CorelDRAW! to colour my own art in the coming future, but life has made that exercise difficult, so I make do with what I can in the mean time.

And if you don't have the budget for a graphical suite, there's always Inkscape, but you must learn it every /n/ updates from scratch, it seems.

See