back to article Nukes tests caused space weather, say NASA boffins

Space weather is usually driven by the Sun – but a bunch of data about Cold War nuclear tests has given NASA boffins the chance to measure whether humans can affect what goes on in Earth's neighbourhood. The once-classified data records high-altitude detonations that happened between 1958 and 1962, conducted both by America …

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Unhappy

IIRC these were the tests that showed what EMP could do to electronics

The answer was "A lot of damage if they are quite sensitive and use transistors, not so much with valves."

They really were a case of people not even knowing what they did not know.

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Pint

Re: IIRC these were the tests that showed what EMP could do to electronics

"not so much with valves"

That's a huge generalisation. If you made a valve the size of a MOSFET, it would have a similar inherent vulnerability to EMI, and more than a bipolar transistor. The reason that it's better "with valves" is simply the size of the things, it's harder for the induced currents to damage big metal electrodes. Mostly, it's not the technology, it's the ruggedness of the components*. Of course, if you know what you're doing, you can take advantage of the small size of transistors. The induced currents depend on the loop area of the conductors, so, with a small part, it's easier, to shrink the loop area. And put it in a little metal box, and be careful with the signals going in and out.

As for satellites, it's gonna be much easier to launch a machine made from transistors, than from valves like these:-

https://youtu.be/EzyXMEpq4qw

Anyway, I did a bit of research. It seems most of the damage to the satellites was to their solar arrays, stuck out flying through the soup of MeV electrons, rather than to their internal gubbins.

https://en.wikipedia.org/wiki/Starfish_Prime

* Of course, it's a bit more complicated than that. Valve circuits are generally high impedance circuits. Not much current flowing, high voltages. The electric field dominates. Transistor circuits are usually the opposite, it's all about the H-field. A lot of digital electronics engineers were taught by people who grew up with valve circuits, and hence don't get that current flows in loops. This helps to keep me in a job.

http://www.sigcon.com/Pubs/news/noEMC.htm

p.s. For clarification, in that America, a thermionic valve is a vacuum tube.

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Mushroom

Tubes vs. transistors vulnerability

"If you made a valve the size of a MOSFET, it would have a similar inherent vulnerability to EMI"

Don't forget the working voltages of valves/vacuum tubes are also typically higher than that of transistors, so any EMP-induced currents are not as likely to exceed the operational parameters of tubes vs. transistors.

This was late 50s/early 60s tech that was destroyed too--I imagine it would wreak havoc with modern LSI electronics, through we've probably gotten a bit better at shielding them than back in the day.

(the icon choice should be obvious) :)

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Re: Tubes vs. transistors vulnerability

"I imagine it would wreak havoc with modern LSI electronics". LSI? Hello, grandad, the kids are using VLSI! Oh, I just checked, it's ULSI now. Whoops, showing my age too!

As it happens, the modern stuff can be much more rugged. The parts these days all have protection diodes integrated onto their signal pins, and have had since integrated FETs came along. They only work if the power pins are connected, that's why you see those static safe bags for un-mounted components. The diodes conduct only if the input signals go outside of the power supply pins' voltage range, and dump the energy into the supplies. Like you say, all the shielding is much better too, a lot of testing goes into all this stuff.

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Pint

Re: IIRC these were the tests that showed what EMP could do to electronics

Symon says, "That's a huge generalisation. If you made a valve the size of a MOSFET, it would have a similar inherent vulnerability to EMI..."

It's EMP. EMI is a different topic.

Since valves the size of a MOSFET do not exist (and cannot exist at that scale), the generalization isn't really "huge".

Plus, the hard vacuum between the tube elements would be far more resistant to short circuits than a solid state medium.

So your point is invalid for multiple reasons.

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Re: Tubes vs. transistors vulnerability

Due to a design fault on a batch of wafers we accidentally discovered indestructible IGBTs. The transistors that failed had a voltage leak fault, but the ones that still worked but still had the design flaw could be ramped up with as much current as the testing rig was able to produce, they simply would not fail as the voltage leakage acted as a protection against the current.

As for the 200A diodes that were being developed at the time it was very quickly discovered that they didn't just fail when the current was ramped up, they actually exploded, so had to be tested within a sealed metal container. Not quite loud enough to cause hearing damage, but the resultant bang of plastic and metal hitting the sides of the container was enough to make you jump.

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Stop

Re: IIRC these were the tests that showed what EMP could do to electronics

Jeffy says:- "It's EMP. EMI is a different topic."

1) You're wrong. An EMP is a pulse of EMI. Although, EMI is also a record label. Is that what you meant?

2) "Seven satellites failed over the months following the test, as radiation damaged their solar arrays or electronics, including the first commercial relay communication satellite, Telstar, as well as the United Kingdom's first satellite, Ariel." So, the pulse didn't kill them. Have you been watching a lot of stuff like '24' and 'The Matrix'? Those EMPs are fictional. It's not like real life. In real life, we have little metal boxes. Full of ticky-tacky.

Jeffy says:- "Since valves the size of a MOSFET do not exist"

1) MOSFETs can be big, e.g. IPC302N20N3 is 30mm².

2) Tubes can be small, http://newatlas.com/nasa-vacuum-channel-transistor/22626/ which has 150nm feature size.

Jeffy says:- "the hard vacuum between the tube elements would be far more resistant to short circuits than a solid state medium."

Hahaha, good troll! How much do you think your 'hard' vacuum attenuates an electromagnetic field? And how much does it slow down 1MeV electrons? Oh, that's right, it doesn't.

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Re: Valves the size of a MOSFET.

Strictly speaking, valves of such a size do in fact exist. Every pixel element of a plasma TV is a valve diode, and a quick search found this critter.

https://www.extremetech.com/extreme/185027-the-vacuum-tube-strikes-back-nasas-tiny-460ghz-vacuum-transistor-that-could-one-day-replace-silicon-fets.

The problem with EMP is not tiny elements, not directly, it's the wires between them that work just like the wire in Faraday's very first experiment. Magnetic field goes past, a current is induced, NOW the tiny elements get voltages they can't handle and pfft goes the magic smoke.

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Devil

Re: Tubes vs. transistors vulnerability

protection diodes on the external pins is definitely the case for modern components, even for discrete MOSFET components. However, protection within the IC itself could be an issue.

But things designed to work on satellites have been surviving solar storms. I've heard of a few of them over the last decade or two, where people were predicting power outages [this has happened] and satellite outages, and nothing obvious happened. So maybe shielding and I.C. tech is adequate?

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"-460ghz-vacuum-transistor"

IE > 100x greater than the clock of most PCs

And that's basically a PoC.

"it's the wires between them that work just like the wire in Faraday's very first experiment. "

Not really.

The big issue is the oxide layer between the Gate and the Drain and Source. From some angles this looks like a capacitor, with a very thing dielectric. This allows a very small current (input impedance of Giga ohms give microamp input current) with a reasonable voltage to switch the device. But the kind of big (Kiloamp) very fast current pulse of an EMP can punch holes through that oxide layer, which isroughly 1/10 the smallest feature size on a chip. In fact it can vaporize the layer.

Miniature valves also have this but the dielectric is a vacuum. Once the pulse is gone the device recovers. That makes them much more resistant to EMP but electrons also move faster through vacuum than a solid (they just do). That's why they are 100x faster. BTW development work on these was done at GEC in the UK and one of the US National Labs in the 80's (Sandia? Livermore?)

The problem is you have to create some kind of cavity for the electrons to cross and you need to make them run at low voltages without using the classic valve technique of the "oxide coated cathode." This has historically meant making very sharp points so that although the voltage is low the field gradient is very high (EG 1 Billion Volts/Metre IIRC).

The other problem is the device density. They got to SSI before the various programmes ended. I'd guess a Field Emission Gate based version of the LS 74181 ALU (79 transistors IIRC) would be quite something. These chips were the basis of the PDP 11, Alto workstations and LISP machines, among others.

A PDP clocked at 470 GHz anyone?

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Unhappy

"a valve the size of a MOSFET, it would have a similar inherent vulnerability to EMI, "

"* Of course, it's a bit more complicated than that. Valve circuits are generally high impedance circuits. Not much current flowing, high voltages. The electric field dominates. Transistor circuits are usually the opposite, it's all about the H-field. A lot of digital electronics engineers were taught by people who grew up with valve circuits, and hence don't get that current flows in loops. This helps to keep me in a job.

I can't think, why since you don't seem to know that MOSFETs (which is what all LSI digital is made of) are much more akin to valves than bipolar transistors, being voltage switched, not current switched devices.

The input current to a MOSFET is in the nA (or lower) range which for a 2V operating voltage (to keep the math simple) V=IZ of 500 M Ohm.

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Ogi
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Re: IIRC these were the tests that showed what EMP could do to electronics

> Since valves the size of a MOSFET do not exist (and cannot exist at that scale),

Ahem...

https://www.theregister.co.uk/2012/05/24/nan_vacuum_tubes/

http://spectrum.ieee.org/semiconductors/devices/introducing-the-vacuum-transistor-a-device-made-of-nothing

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Stop

Re: "-460ghz-vacuum-transistor"

" Gate and the Drain and Source. From some angles this looks like a capacitor, with a very thin[] dielectric. "

In fact, from every angle! Keep this in mind.

"But the kind of big (Kiloamp) very fast current pulse of an EMP can punch holes through that oxide layer, which isroughly 1/10 the smallest feature size on a chip. In fact it can vaporize the layer."

No, it's voltage that breaks down a dielectric. Not current.

https://en.wikipedia.org/wiki/Electrical_breakdown

One quick question for you. How does an EMP induce Kiloamp (sic) current pulses in circuitry? What's the coupling mechanism.

"Electrons move faster"

No-one gives a hoot about the speed of electrons in a circuit. They travel very slowly, a few µm/s.

https://en.wikipedia.org/wiki/Drift_velocity#Numerical_example

It's the speed of the electric field that matters.

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Stop

Re: "a valve the size of a MOSFET, it would have a similar inherent vulnerability to EMI, "

"I can't think, why since you don't seem to know that MOSFETs (which is what all LSI digital is made of) are much more akin to valves than bipolar transistors, being voltage switched, not current switched devices."

I can't think why you don't seem to know the difference between resistance and impedance.

https://en.wikipedia.org/wiki/Electrical_impedance#Resistance_vs_reactance

You have already pointed out that the gate of a MOSFET looks like a capacitor. In a real circuit, the gate is switching on and off. That charges and discharges the capacitor. When the gate is switching at 100's of MHz, the current soon mounts up. This is why your PC's CPU has a fucking great big piece of aluminium stuck to it to get rid of the heat generated.

Now, the same thing could apply to valve circuits. But here's the rub. Back in the day, valve circuits were big things with tiny gate currents switching very slowly, compared to modern logic circuits. This means that most of valve logic stuff is high voltages with tiny currents, connected by wires floating around in the air. The impedance of all these wires makes it a high impedance circuit, where the electric field dominates. Modern circuitry is switching like a bastard, pouring current into the tiny capacitors which are the gates of the MOSFETs. The connections between the components are printed onto sheets of fibre glass bonded in layers with ground planes next to the conductors, maybe 0.1mm away. This means in modern circuits, the conductors have an impedance of maybe 50 ohms. (Remember, impedance, not resistance) This makes these circuits low impedance, where the H-field dominates. Lots of current, low voltages. Remember, the impedance of free space is 377 ohms. Below that, the H-field dominates the electric field.

https://en.wikipedia.org/wiki/Impedance_of_free_space

Please let me know if you have any further questions you think I can answer for you, but before I sign off, one thing to bear in mind. Before advocating the use of 'reliable' valves over 'delicate' transistors (bipolar or FET types) do a bit of googling of MTBF.

https://books.google.co.uk/books?id=D4nLBQAAQBAJ&pg=PA6&lpg=PA6&dq=vacuum+tube+mtb#v=onepage&q&f=false

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Anonymous Coward

Fcukwits reach the top too.

If Theresa May isn't example enough, this goes to show that deluded fcukwits reach the top of any organisation and have no idea of the principle of looking after what you have been given to look after, i.e. you're just the current caretaker.

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WTF?

Re: Fcukwits reach the top too.

What the hell are you on about?

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Re: Fcukwits reach the top too.

If you're going to post a mad non-sequitur, at least make it something that makes sense by itself. Or is funny.

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Anonymous Coward

Re: Fcukwits reach the top too.

I think he blew a valve!

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Anonymous Coward

Re: Fcukwits reach the top too.

Don't let the original AC near any firearms.

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Trollface

I reckon any such effects were fairly mild and quite transitory compared to the first nuclear test's uncertainty regarding whether or not it will set the entire atmosphere on fire...

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Mushroom

"Now I am become Death, the destroyer of worlds."

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Boffin

Indeed the words of Krishna, eighth avatar of Vishnu, are always worth quoting.

I can't take the credit, I had thought it was one of those biblical ones, d'oh...

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I watched the video from Nasa Goddard on YouTube last night. They do some interesting ones, generally short and to the point.

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Now this is something interesting that NK could do with those nukes without getting instantly flattened - fire a nuke straight up (even NK should be able to do that) and watch the fun as satellites go down and power grids falter. Call it a "test". Demand money to not carry out any further "tests".

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Anonymous Coward

Norks "getting instantly flattened"

They'd get flattened. Perhaps not instantly, but the world powers would absolutely end the Nork regime within weeks. No question. No doubt.

Perhaps the world powers could outfit several container ships with thousands of containerized cruise missiles each. Park them off the Nork coast, and launch an eco-friendly non-nuclear regime-ending attack.

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Devil

Re: Norks "getting instantly flattened"

"thousands of containerized cruise missiles each."

or a couple of U.S. submarines outfitted with a few hundred... [I bet that's already the case, parked offshore waiting for the 'go ahead' orders]

No need to underestimate the capability of the U.S. military. >20 years ago, when I was in the Navy, we had some serious capability (my boat helped to test tomahawks and GPS). I can only imagine that it's improved "that much more" since then, and whatever Kim Jong Fatass is working on now looks like 1950's tech...

that being said, I would expect our tech for resisting EMP is pretty good, too.

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Re: Norks "getting instantly flattened"

I would expect our tech for resisting EMP is pretty good, too.

I worked in military development early on (early 70's) EMP, Tempest, and other things were part of specs for electronic equipment and test parameters were exceeded just "see what will happen". I haven't a clue what the specs, etc. are like now but I imagine they've come a long way.

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Re: Norks "getting instantly flattened"

but the world powers would absolutely end the Nork regime within weeks. No question. No doubt.

I think you underestimate the Chinese and Russian's grasp of strategy, which is very advanced - far better than any Western power. They are prepared to tolerate a HUGE amount of inconvenience from Fat Boy Kim for the simple reason that FBK's posturing is entirely anti-American. Any collateral damage to the Sorks or Japan is not a problem, and FBK's comedy villainy serves to keep the US tied up militarily, diplomatically, and to a much smaller extent economically. FBK is a bloody nuisance, but with no upside scenario for the Yanks, because the Chinese won't allow them to do their trademark "regime change", as seen in Afghan, Iraq, Libya, Ukraine, and attempted in Syria.

If we agree that the US have the most advanced satellite capability, then if FBK screwed most LEO satellites, that would be a net win for China and Russia - albeit they'd lose their own eyes in the sky.

Imagine FBK as an act of (gruesome) theatre, now consider that China and Russia have royal boxes, have paid for the performance and plenty of popcorn. The US are the pantomime knight, but forbidden to slay the dragon. It isn't a good situation, but that's the outcome of seventy years of aggressive imperialism.

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The left out the fact that those EMP knocked out part of Hawaii's power grid. So depending on were the nuke goes off you could screw up a country not just the sats.

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Linux

Fallout

I'd rather know how much radioactive fallout was spread around the globe during all the open air nuclear tests and the effects on cancer rates.

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Re: Fallout

I'd rather know how much radioactive fallout was spread around the globe during all the open air nuclear tests and the effects on cancer rates.

Some and "very little"[1].

[1] Depending on proximity to said nuke when it's going off..

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Anonymous Coward

Re: Fallout @bearbonez

I think all five got leukemia.

https://www.youtube.com/watch?v=1VZ7FQHTaR4

Standing under an atomic air to air weapon.

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Re: Fallout

I'd rather know how much radioactive fallout was spread around the globe during all the open air nuclear tests and the effects on cancer rates.

General population cancer rates from nuclear testing were below the level of statistical noise, i.e., somewhere between jack and squat. For the unlucky folks caught in prompt fallout from tests (e.g., wayward Japanese fishermen) the matter's different.

This jumps into the middle of a long article, but gets you closer to the statistics rather than general background on nuclear fallout. Using the faulty assumption that any exposure to radiation is significant, upwards of 50,000 additional cancer (48,000 thyroid, 2,000 leukemia) cases in the US might've occurred from 1950 to 2010. Over the same period, about 25 million cancer cases (171 per 100,000 per year) would've occurred without the fallout, including about 400,000 thyroid and 1.5 million leukemia cases.

Statistics say there might be a cancer spike from the fallout, but it's basically impossible to identify those additional cancers since they look no different than the same cancers caused by other sources. There was no noticeable spike in actual cancer rates that can be attributed to radiation. For example, global lung cancer rates went up in the late 20th century, but so did smoking and industrial pollution. Cancer diagnosis rates are also climbing because of better medical technology, and cancer deaths climbed because of long lives - people used to die before cancer could get them in old age.

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Re: Fallout @bearbonez

I think all five got leukemia

According to the camera operator George Yoshitake (the only one who didn't volunteer to be under the bomb), all six developed cancer in their 40s and 50s. Four would die of it, but not exactly promptly. Cancer deaths among the group:

Colonel Sidney Bruce died in 2005 at age 86 - unspecified cancer

Lt. Colonel Frank Ball died in 2003 at age 83 - unspecified cancer

Major John Hughes died in 1990 at age 71 - unspecified cancer

Major Normal Bodinger - apparently alive in 2012, died sometime later of cancer

Those not killed by cancer:

Major Don Luttrell had colon cancer, but survived to die of something else in 1987 at age 63.

George Yoshitake had stomach cancer, but was alive in 2013

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Re: Fallout @bearbonez

Don Luttrell. 91 years old.

"LUTTRELL, Donald Allen Col Donald A. Luttrell, USAF (Ret) passed away on December 27, 2014 at Presbyterian Hospital of Dallas. He was born on September 27, 1923 in Hatfield, Arkansas"

http://www.legacy.com/obituaries/dallasmorningnews/obituary.aspx?pid=173687969

http://www.huffingtonpost.com/2012/07/20/george-yoshitake-nuclear-test-five-5-men-nevada_n_1687233.html

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Mushroom

Re: Fallout @bearbonez

I think pretty much everyone now agrees that above ground testing is bad, and being close to a ginormous radiation source like an atomic bomb increases your chance of getting cancer. Then again, so does smoking, asbestos, certain industrial chemicals, and so forth.

And the truth about fallout: within a short period of time, nearly all of it decays into low-level or non-radioactive materials. A few things like Co-60 hang around for longer, but they all end up being washed away by rain, blown away by wind, and diluted to statistically "un-detectable" levels. At that point, they don't do squat.

In a localized area, fission products from 50 lbs (or so) of uranium is pretty nasty. evenly distributed around the world, not so much. Thermonuclear devices would create a lot more material as neutron-activated "whatever used to be where the crater now is". But that's likely to be short-lived as well, except for things like Co-60 [which would be formed from Fe-59 + neutron]. Fortunately that, too, will eventually be washed or blown away, to levels "significantly below background".

/me points out that radioactive material is naturally occuring, including "natural reactors" formed by naturally occurring Uranium and other fissionable materials. The sun is the #1 radiation source on the planet, and you'll get more additional exposure flying during the day at 20k feet than from any amount of fallout remaining from cold war nuclear tests. Or Chernobyl. Or Fukushima. (unless you go there and directly expose yourself, but that would be kinda dumb)

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Re: Fallout @bearbonez

Don Luttrell. 91 years old.

Thank you! I knew I should've gone further than my first two references, but I was short on time. This is where I got the 1987/age 63 idea, with some more information in this article.

Too bad it's too late to edit my prior post.

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Re: Fallout

You want to know what kills *LOTS* of people via man-made airborne contaminants? Coal-fired power stations.

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Very interesting to watch: Nukes In Space - The Rainbow Bombs.

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Anonymous Coward

Nothing compared to my farts:

My mother had the vicar and the vicar's wife to tea

They cleared the room, they blamed it on the dog

But it was me.

[Chorus:]

I've farted, I've farted,

I've made a trouser cough,

I've whistled in my Y-fronts,

I've just peeled one off.

I've blown my bowel bugle (Alt: I've blown my bloody brains out),

I've been eating peas,

I've broken wind,

I've dropped my guts,

Open the window please

I've been eating cabbages, prunes and pears and beans,

Drinking Dandelion & Burdock, and you know what that means!

Polluting the environment, my friends leave me alone,

The front of me sings tenor and the rest sings baritone...

(Repeat Chorus)

[Interlude:]

Bubbles in the bath! (echo: Bubbles in the bath!)

Real rip snorters! (echo: Real rip snorters!)

Up on one cheek and hope it don't make a noise.

Window rattlers! (echo: Window rattlers!)

Cushion creepers! (echo: Cushion creepers!)

Don't shake your leg and keep it in your corduroys.

A gentleman tells before it smells, he waves his jacket 'til it's gone;

But I'm the kind of sneaky bugger, who lets off and doesn't let on!

I let them go in lifts, in queues, in phone-boxes and trains,

And when they stink, the people blink and blame it on the drains.

© Ivor Biggun, genius.

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Re: Ivor Biggun

egad! Thanks, AC, for exposing me to such genius. For my fellow left-ponders not familiar, here it is with the music.

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Anonymous Coward

Re: Ivor Biggun

>Thanks, AC, for exposing me to such genius.

There's more classics:

The Winkers song (misprint)

Bras size 45

My Brother's got files (misprint)

The Ukelele Man

Plus loads more.

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Coffee/keyboard

Re: Ivor Biggun

egad! Thanks, AC, for exposing me to such genius.

----------------------------------------------------------------->

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Anonymous Coward

Thermionic valves ...

Still taught to RAF engineers who have to overhaul radar installations ...

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Devil

Re: Thermionic valves ...

tubes/valves still have a lot of use in electronics. In many ways there's no better way to get really high power in an RF circuit than with a water-cooled power tube (like commercial radio transmitters). I don't believe there are any megawatt UHF MOSFETS out there, though it's possible I haven't kept up...

What modern tech can do is make them smaller, and use exotic materials to make them last longer.

As for learning electronics with valves/tubes, sometimes it just looks cool to see glowy bottles that look like they're doing something.

(there's also a lot of audio purists and musicians who swear by their tube amplifiers)

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Thumb Up

Re: musicians who swear by their tube amplifiers

The Vox AC-30 is a thing of beauty ...

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Coat

Re: musicians who swear by their tube amplifiers

"The Vox AC-30 is a thing of beauty ..."

SaidJimmy Page, no less.

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Nothing cooler looking...

..than the ethereal blue glow of a hard working amplifier or rectifier tube.

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