copper crisis?

Interesting ! And makes sense with waveguide being so smooth and all.

On a sunny day (Sun, 17 Jul 2022 10:36:09 -0700) it happened snipped-for-privacy@highlandsniptechnology.com wrote in snipped-for-privacy@4ax.com:

Dunno, I know about tubes as waveguides in GHz stuff. Not sure the coating on the inside (if any) matters much (somebody will correct me I am sure), but smooth surface is better (no reflections) tried everything from alu chimney pipes to soldered together food cans.. google 'cantenna'.

For lower frequency coils at up to to a few hundred MHz I always use silvered wire.

What FET do you use for that high power variable programmable GHz load?

My load board works at KHz, not GHz. It's for aircraft equipment testing, and the most common frequencies are DC and 400 Hz. Some alternators get into the mid audio range.

I'll use four of IRFPS37N50A, which spec at 446 watts each.

The Pockels Cell driver was SiC.

We've been mining the asteroids? When? Which one?

They are running scared of the synthetic diamond producers now:

Technology for making them is not unlike some semiconductor processes but with rather more aggressive conditions!

and tried their best to convinced everyone that the synthetic diamond isn't quite as good as the real thing (I guess not enough blood on them)

And that manufacturers of synthetic diamonds should lasermark them so you can tell it is synthetic

mandag den 18. juli 2022 kl. 16.08.01 UTC+2 skrev snipped-for-privacy@highlandsniptechnology.com:

how happy are they in linear mode? the datasheet SOA doesn't show DC

Yeah, switcher-rated fets can blow up at low power in linear mode. This one is good for a kilowatt dissipation for 10 ms, and we'll be running at 100 watts max DC per fet. It might be prudent to limit the peak voltage to 250 maybe to keep low in the SOAR.

We'll test it for sure. Our FPGA will snoop voltage and current pretty often so it can protect the fets.

We'll have 4 fets on the CPU cooler. In DC mode, each fet will dissipate 100 watts max. Dumping power from an AC source, each dissipates 50 watts.

The decision to make is, how hot can we allow the cooler to get? 75C?

The cooler itself seems to be about 0.25 K/W at max fan speed.

I call bullshit on this, same with any other weird future crisis. None of the claims are anything but laughable. I like the "data processing and storage" theory of where all the copper is going now.

You can edgewind copper strip. Copper is one of the best examples of malleable that there is.

I reckon you could tell them apart by mass spectrometry or radioactivity. True old diamonds will be severely C14 depleted.

The local newspaper did a commercial puff for diamond jewellery and claimed that al the vapour deposited synthetic stones were laser-marked.

Sounds plausible but built-in features would be easier and cheaper to find.

Natural C-14 shows up at the the roughly one part per trillion level, so you have to volatilise a trillion C-12 atoms to see just one C-14 atom in freshly photosynthesised carbon-containing compound. This still isn't all that much, but you are looking for needle in a haystack.

Nah, you just make the new ones out of coal. ;)

Cheers

Phil Hobbs

IIRR you grow gem quaiity diamonds by plasma enhanced chemical vapour deposition, from a stream of hydrogen and methane (mainly hydrogen). Natural gas is mostly methane, and it's spent long enough underground to be just as short of C-14 as coal. Turning coal into methane would be a waste of effort.

Ah, the Terry Pratchett sword. Great story.

The artificially created diamonds are actually better. The propaganda to use "real" diamonds faces a loosing battle.

I remember when De Beers et al. were pushing "expert suggestions" that the right price for an engagement ring was _four_month's_pay_.

Hint: the right sort of girl to marry is the sort who'd be charmed by the idea, and then give you a dope slap for making her start out married life in a financial hole that large.

Cheers

Phil Hobbs