Return of the Vacuum Tube 313
sciencehabit writes "Peer inside an antique radio and you'll find what look like small light bulbs. They're actually vacuum tubes — the predecessors of the silicon transistor. Vacuum tubes went the way of the dinosaurs in the 1960s, but researchers have now brought them back to life, creating a nano-sized version that's faster and hardier than the transistor (abstract). It's even able to survive the harsh radiation of outer space."
Gives a whole new meaning... (Score:5, Funny)
...to the phrase "a series of tubes."
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"TUUUUUUUUUUUUUUUUUUUUUUUBES!"
Soviet Russia (Score:5, Interesting)
When Viktor Belenko defected to Japan with a MiG-25 fighter jet in 1976 (state of the art Russian aircraft back then, meant to counter our F-15) it was discovered that most of the electronics onboard the aircraft were built with micro-miniature vacuum tubes! The reason being that the fighter jet was designed for presumably nuclear war situations, and the Russians wanted to ensure that EMPs from nuclear explosions would not permanently damage the electronics, so the aircraft could still fly and fight even after exposure to any nearby nuclear explosions that were still distant enough to not physically destroy the aircraft.
Re:Soviet Russia (Score:4, Interesting)
Sorry to be a whiny bitch, but the MiG-25 was actually designed to shoot down the XB-70 Valkyrie [wikipedia.org]. The XB-70 project may appear to be a failure in that it only produced two prototypes at enormous cost, but it achieved what it was supposed to in that the USSR spent a fortune building a fleet of interceptors to shoot it down.
Re:Soviet Russia (Score:5, Insightful)
Sorry to be a whiny bitch, but the MiG-25 was actually designed to shoot down the XB-70 Valkyrie [wikipedia.org]. The XB-70 project may appear to be a failure in that it only produced two prototypes at enormous cost, but it achieved what it was supposed to in that the USSR spent a fortune building a fleet of interceptors to shoot it down.
And now Al Queda does the same thing to use. They employ a few guys with piloting skills and box cutters and we spend trillions trying to hunt down their boss and securing our airports against a non-threat.
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I strongly advise you not to come to the UK, as you obviously have "information which could be of use to terrorists" - an arrestable offence in the UK.
(I strongly suspect that common sense falls into this category, which explains why so many people in the public eye haver so little of it!)
Re:Soviet Russia (Score:5, Insightful)
Sorry to be a whiny bitch, but the MiG-25 was actually designed to shoot down the XB-70 Valkyrie [wikipedia.org]. The XB-70 project may appear to be a failure in that it only produced two prototypes at enormous cost, but it achieved what it was supposed to in that the USSR spent a fortune building a fleet of interceptors to shoot it down.
This analysis is flawed - the threat of the XB-70 accounts only for the development of the Mig-25, not its production. The B-70 program was cancelled in 1962 but production of the Mig-25 did not begin until 1969.
It is debatable whether the money spent on the full 1100 Mig-25 production run was the best investment in air power that could have been made, but the Mig-25 has proved to be of historic importance as a reconnaissance aircraft. Overflights of Israel were pivotal moments leading up the Six Day War, India uses them regularly to monitor Pakistan in peacetime and in war. Its ability to outrun opponents has proven to be valuable in battle.
Re:Soviet Russia (Score:5, Interesting)
Your post and the GP's post are in agreement, I think. The XB-70 Valkyrie was designed to drop nuclear bombs on Soviet cities. The MiG-25 was designed to shoot it down. If one XB-70 dropped a nuclear bomb, and the EMP disabled the transistor-based radars of all nearby MiG-25s, then the other XB-70s would be able to reach their targets unmolested. So the MiG-25 radar was built with vacuum tubes instead.
And in addition, it was a tremendously powerful radar - 600 kilowatt continuous beam - well beyond the capability of solid state electronics of the day.
It was an extremely well designed radar system - it is hard to see how any possible design of the period could have improved upon its many advantages.
Re:Soviet Russia woodpecker (Score:3)
That radar caused tremendous interference on the ham short wave bands. It got the name "the Russian Woodpecker" since that is what the interference sounded like, a flock of angry woodpeckers.
Yep! (mod parent up a bit more...) (Score:3, Interesting)
And the funny thing that it was even not that "secret" of a technology (application was, of course!), I remember reading about "new life of a vacuum tube" in Soviet magazine for technically-inclined kids ("Yunyi Technic" [wikipedia.org]) sometime in my early teens, late 70s - early 80s -- I definitely remember reading about thin-film integrated vacuum tubes technology, and, I think, about it's rad-hardness (not using that word, of course, or better half of the reason why it is important ;-) ).
Paul B.
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Interesting... probably also why, in the 1980s/early 1990s when tube amps started to make a resurgence because of their warm distortion, the only place you could still get vacuum tubes was a supplier in Russia. I remember this distinctly when I obtained three 1970s era vacuum tube amps in the late 1980s and had to order vacuum tube parts from a site in Russia while the cold war was still going on because there were no remaining vacuum tube manufacturers anywhere else in the world (that I could find at least
Re:Gives a whole new meaning... (Score:4, Informative)
Re:Gives a whole new meaning... (Score:4, Informative)
former communist states (now that Putin has installed himself as supreme soviet, is Russia still non-communist?).
I dunno how a person can be a "supreme soviet" (soviet = council; "supreme soviet" was the name for the parliament of most communist countries). Anyway, Russia is still decidedly non-communist, since it has full-fledged private property on everything including means of production. It's an authoritarian capitalist country, much like Spain and Chile were back in the day.
Re:Gives a whole new meaning... (Score:4, Interesting)
Since there aren't any vacuum tubes (valves for our European brethren) being made in North America anymore, guitar amp parts suppliers source new tubes from Russia and other communist (i.e. China) or former communist states
Hah, they probably would have done in anyway. These amps often leave the tubes visible from the outside to increase the coolness factor of the device and I can't think of many more effective ways of making it even cooler than having the tubes have strange, exotic shapes and threatening-looking Cyrillic writings on them.
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To "incorrect". I'm referring to the summary, not your post. First, vaccuum tubes never went away. Look inside a Marshall guitar amp and you'll see tubes. Grandma's old CRT TV has a tube; the CRT is a tube. Second, "the predecessors of the silicon transistor" isn't inaccurate but may be misleading, as the two operate in completely different ways and have completely different strengths and weaknesses. Heat and overvotage will kill a transistor, but won't bother a tube at all. OTOH, tubes are physically fragi
Sweet (Score:5, Funny)
Now I can have a tube amp in my mp3 player.
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Dang. Have to undo botched moderation so I have to come up with a moderately witty reply. ;-)
So, how about:
Yeah, you can. But the backpack with the cooling system might get heavy.
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You laugh, but I would *love* to have an AM radio in my MP3 player. So far I have not found any..... now maybe with microtubes, it will be possible.
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You laugh, but I would *love* to have an AM radio in my MP3 player. So far I have not found any..... now maybe with microtubes, it will be possible.
That's what the fillings in your teeth are for, dude...listening to AM radio and the voices of the aliens telling you what to do.
Re:Sweet (Score:4, Interesting)
Now I can have a tube amp in my mp3 player.
Well, they released a motherboard around a decade back with integrated vacuum tube based audio. [neoseeker.com]
:-)
I remembered this as being a separate soundcard, but I couldn't find reference to anything like that online, so I might have been wrong. Still, given that onboard audio isn't- or at least wasn't back then- generally considered to be the best (i.e. not what the audiophiles would have gone for), this seems like a strange mix. As if the valve/tube-based PCI card wouldn't have been weird enough, mind you.
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I remember that, they put it onboard and reduced the PCI slots because they assumed you wouldn't buy a soundcard.
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What the hell are you talking about? Many tubes have multiple gain devices within the same envelope. I remember building a hybrid tube/MOSFET headphone amp a couple of years ago using a single 6DJ8, which has two triodes in it. There's no doubt the motherboard in question only used the tube for VAS and not as an output stage, so there's no reason to use a push-pull configuration.
Re:Pure marketing (Score:5, Informative)
The tube on the AOpen mobo was a 6DJ8/6922, not a 12AX7.
The 6DJ8 is also a dual triode, but it has much higher transconductance because it is a frame grid design. Those tubes were widely used as input amplifiers in vintage Tektronix scopes because of their low noise and high linearity.
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MP3 player? I want a Pip-boy with 'em tiny tubes!
And a reservation for a room in Vault 101 to go with it.
Comment removed (Score:5, Informative)
Re:Sweet (Score:5, Interesting)
Actually it's far more technical than some fuzzy "it sounds warm" bullshit you hear from audiophiles. When you overdrive a tube they have a natural tendency to round over slightly rather than hit a hard limit and flatline. This is similar to tapes which could be recorded above their maximum 0dB point. This creates an interesting form of compression and combined with distortion / overdriving creates a sound that is very difficult to replicate with solid state stuff.
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Amps (Score:5, Informative)
Reel to reels as well (Score:5, Informative)
And they are used in some of the best old-school reel-to-reel recorders. I don't know if they are making new components with tubes, but older tube pre-amps for Ampex and Scully tape recorders are prized by some audiophiles for their "warm" sound. They are also great for creating distortion...over-driving tube pre-amps creates some nice distortion effects which digital components would just clip.
But (and I'm speaking as someone who has been out of radio and audio for many years...I own a hardware store), from what I've seen and heard there are some pretty awesome digital programs that can duplicate nearly any pre-amp ever made. Based on what my daughter can do with her Mac (Protools, FInale, etc) I am pretty impressed at the sounds that can be processed even in a home environment with no need for tubes.
On the other hand, my tube pre-amps do keep the basement warm. :)
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With a Line6 pod, you go directly into the console and that's it.
Re:Amps (Score:5, Insightful)
You may like the distortions produced by tube amps (or transistor amps outputting those same distortions via DSP), but don't pretend they're better at reproducing sound. They are demonstrably not.
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Re:Amps (Score:5, Interesting)
*AFAICR Vox, Fender, Orange, etc all uses the exact same circuit - the valves and transformers came from different suppliers, and some of the metal work was a different shape.
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You have that backwards. Tubes are inherently more linear than transistors. Transistors have small ranges of linear operation and require complex bias control and feedback for audio use. In addition, the harmonic distortion of tubes is primarily even-order which sounds smoother than the odd-order harmonic distortion of transistors.
http://en.wikipedia.org/wiki/Valve_amplifier#Advantages [wikipedia.org]
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I find it interesting that the wikipedia page cites some marketing material by a tube amp vendor as the source for that info. I guarantee if you speak with someone who has designed high-power amplifiers with both tubes and transistors they will consistently tell you the transistors are the only way to go for accurate reproduction.
One of the biggest problems with vacuum tube designs is that it is very hard to keep impedance linearity across the 20-20khz spectrum. When you are trying to drive a speaker whic
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Yep, that detail may be right. But transistors achieve a much higher gain (even more when you couple several of them), what lets you put them in bias control and feedback circuits. Inside those circuits they are way more linear.
The final result is that transistor based amplifiers are (nearly without exception) more linear than the tube based ones.
Re:Amps (Score:5, Informative)
Yes, transistor audio amplifiers are "way more linear" with gobs of negative feedback applied, if THD, (Total Harmonic Distortion), is your measurement criterion. ANY amplifier is more 'linear' with correctly applied negative feedback. The basic premise is that added harmonics are bad - if you feed a pure sine wave into an amplifier, you want a pure sine wave at the output. The problem is that in audio, THD is a fundamentally flawed measurement with very poor correlation between lab measurements and listening tests.
THD measurements are taken as the ratio of the total power of all harmonics to the power of the fundamental, with no weighting of any kind applied. The trouble is, human hearing doesn't respond to harmonic distortions in this linear fashion - our ears find higher order harmonic distortions much more apparent and objectionable. [nutshellhifi.com]. This deficiency was noted by prominent BBC engineers D.E.L. Shorter and Norman Crowhurst in the 40's and 50's, when they proposed weighting harmonics by the square or the cube of the order; but their voices were drowned out by market forces that wanted a simple, flattering figure of merit that made the newer, more powerful pentode-based amps, (with lots of negative feedback), look better on paper than their lower-powered triode predecessors. The market won out over scientific and technical accuracy, (it usually does), and today engineers the world over, ignorant of this history, mistakenly believe that low THD is the gold standard for measuring and defining audio amplifier quality. (For a good technical analysis of distortion and the sound of an amplifier, see Lynn Olson's excellent investigation. [nutshellhifi.com]
By the way, in the 'tubes vs transistors' debate, good triodes have the advantage of being more intrinsically linear than transistors. This means that they require less negative feedback to tame their distortion, and often sound wonderful with NO negative feedback. The THD figures of amps built this way are often quite poor, but look at their spectra and you'll see predominantly second- and third-order, with a smooth and rapid falloff of higher order harmonics. Occasionally solid-state amps can give this kind of performance, but tubes have an easier time of it. Designing a good-sounding, (as opposed to good-measuring), audio amp, requires a lot of skill, and a lot of knowledge about distortion mechanisms and how to counter them. Unfortunately the prevailing practice in HiFi is to add more gain, throw most of it away with additional NFB, get a nice low THD figure, and call the job done. Amps designed this way generally sound like shit, if not initially, then after 20 minutes or so of listening, at which time listening fatigue sets in.
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The same control theory that was developed in the tube era is applied to an even greater degree in transistor based amplifiers.
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Basically when clipping a transistor sounds horrendous... you must always operate a transistor well bellow its clipping threshold (hard to do with analog instruments)
Sounds to me like they are using the wrong sized transistor.
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They're a simple solution for guitar amps where the distortion is intentional..players can fiddle with the bias to get the distortion they want.
Also there's an inherent capacity to deal with large overloads and high powers as compared to transistors.
No kidding (Score:3)
A good modern transistor amp can do precisely what a good amp should: Disappear. They can have distortion low enough, noise low enough, be linear enough, and so on that they don't introduce any audible artifacts of their own. You can swap well built ones around and hear no difference.
That's what you want out of a good reproduction amp, just a wire with gain effectively. It should introduce no changes of its own. Of course you can't have one that is flawless and does NO changes but you can have one that the
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Fidelity and appealing sound are different issues. Most old school recording engineers hated digital recording at first because it didn't sound as good as analog tape. They deemed that digital was inaccurate and blamed it on flawed methodology, "rounding errors" etc. But the fact is that the tape, like tubes, were coloring the sound artificially in a pleasant way while digital was only trying to be neutral.
Nowadays, tape is pretty much dead, tube-based recording consoles are pretty much non-existent, as
Re:Amps (Score:5, Interesting)
<memorylane> One of my lab partners in my EE Lab class played bass guitar. He wanted a tube pre-amp, but didn't want to spend $1,000 for it. So we built one as our lab project. We pulled a transformer out of an old Hammond organ, pulled tubes out of some old random stuff in a cabinet in the lab, threw in a pair of 12,000 uF caps, and four ceramic diodes for the rectifier. Then we had to code our own SPICE model for the tube so we could simulate it. That was one stout amp. Except the transformer put out a really unstable power waveformm, so one of our ceramic diodes exploded (tripping a breaker and taking out power in that wing), which was actually kind of cool. But we had to find a different transformer. Another time I accidentally grounded the 600-V node, which blew a big hole in our trace line and evaporated the solder off of one of our caps. The edges of the trace line survived, so we soldered the cap back in, powered it up, and it worked great. It was perfect except we were never able to get rid of the 60 Hz hum when it was plugged in. If you unplugged it, you could play for about a minute before the caps drained, and it sounded spectacular.</memorylane>
I miss those days. Now I just sit around writing patents and pleadings all day.
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The hum was actually caused by the caps being too large. Try an additional 50 or 100 uF caps and you'll see what I'm talking about. .1 maybe) to clean up/filter the high freq noise. Remember, it's really an AC circuit you're working with; I
Power supply caps are generally sized by the rail current they're strapped to, stating in simple terms. Their should also be some very
small ceramic caps (.01 or
think the idea of big caps came from enhanced after-market car stereos - which are a true DC circuit.
Vacuum tubes have never left! (Score:5, Interesting)
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Don't forget guitar amps. You're not gonna get the same aesthetics out of silicon. The best amps all pretty much use vacuum tubes.
Re:Vacuum tubes have never left! (Score:5, Informative)
1960's?
The amplifying triode vacuum tube was invented near 1907.
The transistor itself in 1947.
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...and linear proton accelerators. Vacuum tubes are still used [thalesgroup.com] for particle accelerators.
Re:Vacuum tubes have never left! (Score:4, Informative)
A lot of microwaves have a vacuum tube for the display too.
(The erie blue-green ones) VFD [wikipedia.org]
Re:Vacuum tubes have never left! (Score:5, Informative)
Uh... Microwave ovens use a magnetron http://en.wikipedia.org/wiki/Microwave_oven#Design [wikipedia.org] I've repaired many a Microwave ovens and I have never seen any vacuum tubes.
Too smart for your own good. A magnetron [wikipedia.org] is a vacuum tube [wikipedia.org]. Not all vacuum tubes are transparent. Hell, the "vacuum tube" in the article has neither a tube or a vacuum!
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As long as we're quoting Wikipedia:
http://en.wikipedia.org/wiki/Cavity_magnetron
The cavity magnetron is a high-powered vacuum tube that generates microwaves using the interaction of a stream of electrons with a magnetic field.
Re:Vacuum tubes have never left! (Score:5, Informative)
Uh... Microwave ovens use a magnetron http://en.wikipedia.org/wiki/Microwave_oven#Design [wikipedia.org]
I've repaired many a Microwave ovens and I have never seen any vacuum tubes.
Nathan
Indeed they do use magnetrons. And to quote from the first line of the Wikipedia article on magnetrons" [google.co.uk] "The cavity magnetron is a high-powered vacuum tube..." (my emphasis). Do you repair the microwaves with your eyes closed?
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The device that produces the microwaves is called a magnetron and is a vacuum tube (vacuum tubes do not have to be made of glass, in fact, a lot of early vacuum tubes used in radios were metal).
OFFTOPIC: Moderation (Score:4, Informative)
Thanks for modding me down jackass. You could have INFORMED me of that fact without punishing me with a -1 whip. (And if it wasn't you, then I direct my comment to the other fucker that did it.)
You can't post and moderate in the same article. Posting removes all your moderations in that article.
Re:Vacuum tubes have never left! (Score:4, Informative)
So, why not combine dozens (or hundreds) of transistor output stages to get the equivalent of a single valve-based amplifier? That way, you get the same output power, but you never need to replace any burned-out tubes.
Because then the circuit would be much more complex (the need for matching all the small transmitters so they all work well in parallel) and a failed transistor could result in a lot of failed transistors. Tube circuits are simpler and tubes can tolerate overloads better.
Oh, and another thing. HVDC substations replaced their mercury valve rectifiers many years ago because new silicon-based technology could do the same job, at the same power level, with much less hassle. That's a higher level of power than broadcasting.
As the result of a rectifier is DC, it is simpler to combine a lot of smaller components in parallel and they dissipate less power than a transmitter would (since the output devices have to operate in linear mode in a transmitter, while they are on or off in a rectifier)
Re:Vacuum tubes have never left! (Score:5, Informative)
> At low power levels (e.g. 10kw) transistorised VHF/UHF output amplifiers are fine. Additionally, you can get a higher power output by operating multiple VHF/UHF output amplifiers in parallel - which also gives some redundancy for transmitter maintenance.
See Pentium 100's reply; he hit the high points. But it's essentially a matter of cost-effectiveness. If you tell me, "I need 30,000 watts at 100 MHz (a typical FM arrangement), I'm going to use a tube. Even after paying $5,000 for the tube and building a 10,000 volt, 5A power supply, I'd still come out ahead. Combining enough 100-200W solid-state modules to get that kind of power level would be far more expensive.
There's a practical matter, too -- for example, or 50 KW AM stations *do* use solid-state, and they're done as Pentium100 describes: you combine bunches and bunches of modules to get that power level. That's at a much lower frequency, and they can be made very efficient .. . .. but with full modulation, our Nautel transmitter runs a 300V primary supply and draws in excess of 300 amperes(!). There are giant 3/0 cables (they look like booster cables!) running all over the inside of that thing just to handle the current.
Can't cheat physics: power = voltage times current.
But I'll add this: Some competitively-priced solid state high power transmitters have begun appearing, so I have hope for the future. (We're looking at some of the new Nautel FM units ourselves; www.nautel.com if you're curious.) But seriously, even as recently as 2 years ago, there was no question that a 4CX20000 tube in a tuned cavity was far more cost-effective than trying to do it with solid-state.
But in outer space... (Score:3, Funny)
aren't they just called "tubes"?
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And if we could align them in a series, we'd have Internet in space! BRILLIANT!
Re:But in outer space... (Score:5, Informative)
No, space is a far far harder vacuum than anything we can currently manage on-planet.
A vacuum tube still has between 1 million to 1 billion molecules per cubic centimetre, depending on tolerances. The best vacuum we can currently make has about 100k molecules per cubic centimetre.
Interplanetary space has about 10. Interstellar space has about 1. Intergalactic space has about 1 per cubic metre (10,000 cubic centimetres).
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You're correct. Not sure how I put 10k in there.
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Well played, well played.
500 GHz (Score:3)
low power, high frequency, rugged, ... I say, these things might be useful
Interesting (Score:2)
It mentions that the scale of these things is 150nm, which sounds pretty large compared to modern cpu features. Still, it's a very interesting development.
Not really a vacuum tube (Score:3)
There is 1) no vacuum and 2) there is no "tube." While there is an electron emitter, this device should be called a MOSFET.
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a Metal Oxide / Silicone Field Effect Transistor? 0_o
Outer space is not the limit (Score:5, Interesting)
These "vacum tube like" diamond field emission devices have shown radiation tolerance from 10 to 100 Mrad (1 MGy in SI units), so we are more talking about the levels required for operation in nuclear reactors or close to the beam of particle accelerators.
Obligatory science fiction reference... (Score:4, Interesting)
"Tales of the Flying Mountains" by Poul Anderson
It's a collection of short stories about the "Asteriod Republic" wrapped in a frame of the first interstellar flight. One of the stories features a military vessel whose electronics were built with "TEMMs" - Thermionic Emission Micro-Miniaturized - featured for its radiation hardness.
O... M... G... (Score:4, Interesting)
The article is painful in some aspects
Electrons move more slowly in a solid than in a vacuum, which means transistors are generally slower than vacuum tubes; as a result, computing isn't as quick as it could be.
I'm flabbergasted.
Meyyappan, who co-developed the "nano vacuum tube," says it is created by etching a tiny cavity in phosphorous-doped silicon. The cavity is bordered by three electrodes: a source, a gate, and a drain. The source and drain are separated by just 150 nanometers, while the gate sits on top. Electrons are emitted from the source thanks to a voltage applied across it and the drain, while the gate controls the electron flow across the cavity
This is really a vacuum tube if you add a high dose of immagination. Really
The separation of the source and drain is so small that the electrons stand very little chance of colliding with atoms in the air
Makes me wonder if tunneling plays a part here
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This is really a vacuum tube if you add a high dose of immagination. Really
Well, maybe not so much a classic vacuum tube, since electrons are generated through field electron emission, not thermionic effect. It does look similar to some cold cathode devices though, like neon lamps or maybe plasma display cells. The interesting parts are the very small size and the addition of the gate which allows modulation of the electron flow.
Makes me wonder if tunneling plays a part here
Maybe a bit, but AFAIR electron tunnelling happens at really small scales, in the sub-nanometer range, maybe up to a few nanometers. The gap mentioned in
Small light bulbs? (Score:2)
Television circuit boards: 1975 (Score:2)
Cutting the summary writer some slack, ignoring audiophile amps, ignoring guitar amps, ignoring microwave ovens, ignoring broadcast equipment, and even ignoring cathode ray tubes (which still outnumbered flat panel sales through 2004), consumer television sets didn't go "solid state" until 1975 (I remember it being a big deal to have the "solid state" badge on the front of a new-fangled TV because it meant you didn't have to wait (as long) for it to war
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Many sets were already hybrid or entirely solid state by '75.
GE kept making the portacolor [rwhirled.com] until 1980 or so, but it was the last of the tubed sets (In North America anyway - I imagine Soviet sets were still tube for a while yet, but maybe not). I presume GE just rode out the existing tooling, and when the portacolors finally quit turning a profit/selling they tooled up for more SS sets (or got undercut by Japanese SS sets, either way)...
Though as I've mentioned earlier in this thread, any TV with a CRT isn'
The Tube Dance (Score:4, Interesting)
When I was a young kid, my mother would fix the TV by pulling out all of the TV tubes, wrapping them in news pages, and then carrying them all down-town to a big drug store which had a coin-operated tube-tester machine. She'd plug them into the matching slots one by one and see which ones were good and which were sour. I couldn't help her because I was too short.
Then she'd go to the back of the store to find matches for the sour tubes based on the codes printed on the tube slots. (Often the label was worn/cooked off the tube itself such that the slot labels on the tester were the only way to tell.)
I'd generally consider her a "technophobe", but she did it in a very routine fashion as if she'd done it dozens of times before. People just got used to tubes back then.
At least TV's were partly repairable. Now the repair costs are often more than a new TV. Oh, and Get off my lawn!
Re:The Tube Dance (Score:4, Informative)
The big snag (Score:2)
The military never stopped using Vacuum tubes. (Score:2)
Vacuum tubes aren't that unusual. The US Military has been using them for decades for Night Vision equipment and the best NV equipment is still based on vacuum tube technology. This is what Image Intensifiers are, which comprise more than 90% of new NV equipment.
Less commonly ( and more historically ) the Image Intensifier is a particular type of tube known as a photodiode, but more modern tubes incorporate a lot more technology including electron multipliers ( microchannel plates ) within the tube itself.
B
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Re:Old is new (Score:5, Funny)
Keep seeing all these whippersnappers nowadays wearing the same clothes I wore years ago.
You should have thought of that before you donated them.
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It's not mandatory. It's also not applicable to components.
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Only if you get a Beowulf cluster of them.
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No, it's simply a copy-paste of the article's first paragraph.
Fucking lazy, is what it is.
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If you want to get technical, if you've had a CRT based TV, you had a 'vacuum tube' TV. It just wasn't entirely hollow-state. ;-)
Re:News for who? (Score:5, Interesting)
I believe that anyone younger than 30 now stands a damn good chance of never seeing a vacuum tube or even know of their existance.
Wrong.
If they ever attend a rock concert or watch a video of one (or if they ever take up electric guitar or bass) they'd see walls of them. Usually with big script logos that say "Marshall" or sometimes logos that say "Fender", "Soldano", or "Mesa-Boogie", with a few other brands that are less well-known and typically considered more "exclusive" like Matchless, Framus, Dr. Z, Top Hat, Divided by 13, Bad Cat, Victoria, etc etc.
All the top guitar-amplifier makers' top-of-the-line pro-level models brag of being "all tube". DSP has not yet been able to equal the tone, "feel", and response to the player's nuances that vacuum tubes exhibit. It's really, REALLY hard to model all the variables that affect the sound of an electromechanical device like a vacuum tube with digital signal processing.
I build and sell custom vacuum-tube guitar amps myself, as well as provide service and repair for vintage & modern tube guitar and bass amps. I can also occasionally be found on a stage in a club, or on a festival stage somewhere, playing guitar. I've been doing both for about 4 decades now.
Strat
Re: (Score:3)
I believe that anyone younger than 30 now stands a damn good chance of never seeing a vacuum tube or even know of their existance.
Wrong.
If they ever attend a rock concert or watch a video of one (or if they ever take up electric guitar or bass) they'd see walls of them.
I've never seen a human pancreas, but I've looked at untold thousands of people during my life. If I hadn't done biology at school, I'd probably not even be aware that there was such a thing as a "pancreas", even after looking at all these people.
The previous posters point is that most modern geeks don't know about tubes. Most modern computer geeks aren't guitar geeks (although some of us are -- I even built my own electric guitar once!)
Re:News for who? (Score:5, Interesting)
It has more to do with reputation than with "can't be done otherwise". A 50 cent-a-pop DSP probably has enough power to simulate the good ol' vacuum tube sound.
Well, I guess we'll have to agree to disagree here. For 40 years I've worked at music stores and been in bands, never mind being an amp tech/designer/builder, even worked in avionics and military-related high-end electronics systems, heard many of the very best DSP studio rack processors made costing many thousands of dollars, and my ears and everything else I know and have learned so far during all this time convinces me that, although DSP has gotten much, much better compared to even 5 years ago, it hasn't arrived yet at the point where the human ear can't tell the difference.
DSP guitar tone, clean or overdrive/distortion/effects, does not sound like real tubes *yet*. They will probably get there, I'm not saying it won't happen, maybe quite soon. It's just not there yet.
There's one solid-state amplifier made starting in 1975 that sounds great for jazz guitar. The Roland JC-120 Jazz Chorus 120 amplifier. Beautiful clean sounds. It does have a distortion function, but *nobody* used it once they heard it! :)
Don't get me wrong. If you're in a local small-town working bar/dive band that is mostly there for the $40 to $80 a man per night, and not trying to impress anyone with your tone except the bar owner...just enough, that is, to pay you and keep you on the booking rotation, and you don't want to carry any more than absolutely necessary nor tie up more money than you absolutely have to in an amp, something like one of the "Line 6 Spider" combo amps will "get it done". Sorta like when old people...well, never mind. :-/
Those type of DSP solid state amps are also great for those just starting out, as it has a bunch of effects in software already, no effects pedals or rack effects, cords, etc to bother with, and they're dirt-cheap as amps go. If it breaks, throw it away and buy another just like a disposable lighter.
And yes, I do prefer the vacuum-tube amps, not only because of the sound, but also the warm feeling of old electronics :)
Here's my personal amp that I built recently.
http://i62.photobucket.com/albums/h103/stratman_el84/Testament%2030/cabhead03.jpg [photobucket.com]
4 tubes total. two 12AX7 dual-triode preamp tubes (one a parallel-triode preamp gain stage, the other is the "long-tailed pair" style dual triode inverter/driver tube) and two KT66 beam tetrode power tubes in cathode-biased push-pull Class AB, producing around 30 watts. Volume and Tone controls, Standby/On and Power On/Off toggles. That's it. It sounds fantastic. You can't find a Volume/Tone control setting combination that sounds bad. I keep finding wonderful new tones and sounds almost every time I play it.
The sealed-back dovetail pine cab finished with Tru-Oil gunstock finishing oil with a Baltic birch plywood baffle has a pair of Celestion G12T-75 12-inch 8 Ohm guitar speakers wired in parallel for a 4 Ohm total impedance. It sounds absolutely gorgeous. Combined with that amp, some serious guitar tone-heaven.
I took the amp head into the local Guitar Center store shortly after I'd finished it. They had *nothing* that sounded anywhere near that good. The manager finally noticed the small crowd gathering, and (gently) asked me to cease after he started hearing a couple people asking if I sold amps like that one. :D
Oh, and since you mentioned a "warm feeling from old electronics", here's a little something that's sure to make wherever it is at just a little warmer. And louder. A *LOT* louder.
http://i62.photobucket.com/albums/h103/stratman_el84/Junk/monster.jpg [photobucket.com]
Re:Ahistoric Hyperbole Rant Warning (Score:5, Informative)
Actually an open heater was NOT the way most tubes died. The coating on the cathode that emits electrons when heated gradually decays and emission drops off to the point that the tubes transconductance is too low for it to operate. But the heater rarely burns out, at least not in indirectly heated tubes. Another way they die is that air gradually leaks in and the vacuum becomes too poor. The silver flashing on the side of the tube will then turn a milky white as the chemical "getter" that absorbs air has absorbed all that it can. Once the getter coating is depleted the tube will become gassy. A tube can also die from shorts when closely spaced elements break loose from vibration and touch. Over heating will soften the elements and cause the same effect. Tubes can handle a much higher percent of overload than solid state devices however. Tubes computers were never faster than solid state ones even if the tubes themselves were faster. Because of their size the total wiring in a tube computer is much longer than in a solid state system. In transistors it is the "holes" in the crystal structure that "move" and the speed of light in silicon is lower than in a vacuum for electromagnetic waves. Still these waves have less distance to propergate in an IC than a bunch of interconnnected tubes. Finally note the description of this new tube technology, it is really a "vacuum state" IC. I always wondered when nanotechnology would be applied to thermionic "valves" (as they say across the "pond").
Re: (Score:3)
I have a few devices that use vacuum tubes and I have not encountered a tube that heats up but does not work due to low emissions. They all either work acceptably or not light up at all (a tube full of air also does not light up, at least from the nominal heater voltage). Maybe in the USSR made tubes the heater is the first to go.
Then again, I do not have a tube tester (always planning to build one, but always find something better to do), so maybe most of the tubes in my devices have really low emission, b
Re: (Score:3)
I have replaced a total of two tubes in my devices, both of them were dark. One was a tuning indicator (I got the radio with it bad) and the other was a Soviet version of EL84 - that worked for a year or so and then burned out. In all of those devices I have not seen a tube that does not work but lights up.
Also, the tubes in my headphone amp are on at least 12 hours per day (sometimes I do not turn it off for weeks) and in use 6 years already and they still work. One tube (it was used when I got it, it has
Re: (Score:2)
Um, light travels in copper? How's that work?
light, not necessarily visible (Score:2)
"light" is another term for "electromagnetic radiation"
Although one could quibble about whether or not a EM radiation travels in a copper wire, and technically the speed of progagation of the signal in a copper wire is roughly 0.96c while in a coax cable it's more like 0.66c.
Re: (Score:3)
Hey, it's ok cffrost. Just calm down.
We all know dinosaurs still exist.
Re: (Score:3)
If you're' looking for that 'classic' sound with its harmonic distortions, then yes.. if you're looking for accurate sound, then no.
Re: (Score:2)
The germans already did this in the 20s. Although it is a simple circuit... it is an integrated circuit.
Loewe 3NF [electricstuff.co.uk]