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Return of Vacuum Tubes?





quex
Just read this: http://news.sciencemag.org/sciencenow/2012/05/return-of-the-vacuum-tube.html?ref=hp

...and I have to say, I am very enthused indeed about possible impending access to an integrated circuit that runs at 0.46 terahertz. Can you imagine the processor speed we could juice out of something like that?

Seems like revisiting "old" technologies in our search for improving the modern manifold is paying off... windmills turn into wind turbines, vacuum tubes make a comeback... I'm probably missing some obvious ones. ^^'

Also, I am in love with the name Meyyappan. SO cool.

ALSO also, metamaterials sound fantastic.
coolclay
That is pretty fantastic news. Vacuum tubes are still used in some electronics today, amps especially. They are extremely stable, suffer from very little distortion and can withstand large overload surges. You should see the prices that some of the rarer vacuum tubes go on Ebay it's crazy!
ocalhoun
coolclay wrote:
That is pretty fantastic news. Vacuum tubes are still used in some electronics today, amps especially. They are extremely stable, suffer from very little distortion and can withstand large overload surges. You should see the prices that some of the rarer vacuum tubes go on Ebay it's crazy!

And some are still used in radar systems, where their capacity to handle truly huge voltages and currents without becoming exponentially more expensive is put to good use.

Making a transistor that can handle 32,000 volts would be a huge undertaking... but making a vacuum tube that can handle it is a simple matter of just making it big enough.
chatrack
Hi,

I came to know in some recording studios they still love valve equipments
than modern ic generation equipments
quex
coolclay wrote:
That is pretty fantastic news. Vacuum tubes are still used in some electronics today, amps especially. They are extremely stable, suffer from very little distortion and can withstand large overload surges. You should see the prices that some of the rarer vacuum tubes go on Ebay it's crazy!


I've always wondered about this... when I see OEM tubes up for auction that are for antique electronics, I assumed they were old stock that somebody dug up and is selling to keep the antiques alive, hence the rarity: limited and finite supply. HOWEVER, if there's demand form the music industry, do you suppose (or know for a fact) that people are still manufacturing these original tube configurations somewhere in the world?
quex
ocalhoun wrote:
coolclay wrote:
That is pretty fantastic news. Vacuum tubes are still used in some electronics today, amps especially. They are extremely stable, suffer from very little distortion and can withstand large overload surges. You should see the prices that some of the rarer vacuum tubes go on Ebay it's crazy!

And some are still used in radar systems, where their capacity to handle truly huge voltages and currents without becoming exponentially more expensive is put to good use.

Making a transistor that can handle 32,000 volts would be a huge undertaking... but making a vacuum tube that can handle it is a simple matter of just making it big enough.


Radar, really? Like old radar that's still running somewhere, or even modern newly-installed radar? That's kinda cool. I'm only curious because we have all these radar stations out here in the desert... some of them look like 1960's earth-to-space satellites.
ocalhoun
quex wrote:

Radar, really? Like old radar that's still running somewhere, or even modern newly-installed radar?

The difference is less than you might think, actually.
Even the top-of-the-line, brand new ones are usually using 10-20 year old technology by the time they finally get designed, tested, and installed... they have a very slow development process.

But yes, even some brand new ones use tubes. When dealing with very high energy levels, tubes are sometimes simply the more economical choice.
...Particularly magnetrons -- a specific type of tube great at turning raw pulses of power into specific-frequency, high-power RF.
...Come to think of it, you'll also probably find small magnetrons in most household microwave ovens, even the most modern ones.
Quote:
I'm only curious because we have all these radar stations out here in the desert... some of them look like 1960's earth-to-space satellites.

Those one's definitely have tubes in them! ^.^ Some really interesting ones! Some of those old tubes were amazingly complex, sometimes the size of an oil barrel, and sometimes very complex, with tubes within tubes and all kinds of craziness going on.

Here's a diagram of an old klystron tube design -- an RF amplifier:


And here's what one looks like in real life:


You'd be likely to find something like that in those old radar sets! ^.^
A lot of them used klystrons or twystrons (two in-line klystrons in the same tube) for the main stage of RF amplification before transmitting.
quex
ocalhoun wrote:
quex wrote:

Radar, really? Like old radar that's still running somewhere, or even modern newly-installed radar?

The difference is less than you might think, actually.
Even the top-of-the-line, brand new ones are usually using 10-20 year old technology by the time they finally get designed, tested, and installed... they have a very slow development process.

But yes, even some brand new ones use tubes. When dealing with very high energy levels, tubes are sometimes simply the more economical choice.
...Particularly magnetrons -- a specific type of tube great at turning raw pulses of power into specific-frequency, high-power RF.
...Come to think of it, you'll also probably find small magnetrons in most household microwave ovens, even the most modern ones.
Quote:
I'm only curious because we have all these radar stations out here in the desert... some of them look like 1960's earth-to-space satellites.

Those one's definitely have tubes in them! ^.^ Some really interesting ones! Some of those old tubes were amazingly complex, sometimes the size of an oil barrel, and sometimes very complex, with tubes within tubes and all kinds of craziness going on.

O,O AWEEESOME. Thanks for all this info... I want a klystron accent piece in MY library. ;_;

If the dish is down, it's pretty certain that the unit is no-longer functioning, right...? If so, I wonder if any of these pieces are scavengeable?
Here's a diagram of an old klystron tube design -- an RF amplifier:


And here's what one looks like in real life:


You'd be likely to find something like that in those old radar sets! ^.^
A lot of them used klystrons or twystrons (two in-line klystrons in the same tube) for the main stage of RF amplification before transmitting.
kelseymh
ocalhoun wrote:
Here's a diagram of an old klystron tube design -- an RF amplifier:


And here's what one looks like in real life:


Here's a whole bunch of klystrons and support structure all in a row:



(http://www.flickr.com/photos/gschroeder/6958038698/#/photos/gschroeder/6958038698/lightbox/)

That's part of the SLAC linear accelerator klystron gallery -- two miles of klystrons pumping RF power into a ~10 cm diameter pipe to accelerate electrons and positrons from 0 to 50 GeV.
ocalhoun
quex wrote:

If the dish is down, it's pretty certain that the unit is no-longer functioning, right...? If so, I wonder if any of these pieces are scavengeable?

No longer functioning, surely... but despite that, probably still very valuable.
Whoever owns them will be wanting to do their own scavenging, and they'd probably take exception to anyone else doing so.
(Or maybe they already have, and if you break into one, you'll just find an empty shell.)

...And if you wanted to pull a klystron out of one, you better bring some friends! Those big tubes can get heavy!
The gpn20 I worked had a 95 pound tube (replaced that bastard several times -- it was a 6 hour operation with a 3 man crew)... some of the others I was trained on had tubes that weighed in at a hefty 300 pounds -- before you filled them with a few dozen gallons of coolant fluid.
kelseymh wrote:

That's part of the SLAC linear accelerator klystron gallery -- two miles of klystrons pumping RF power into a ~10 cm diameter pipe to accelerate electrons and positrons from 0 to 50 GeV.

Well, there ya go, vacuum tubes being used in some of the most advanced technology on Earth.
Who said they were dead? ^.^ Like I said, still very useful for high-energy applications.
iocane
There is still vacuum tubes being manufactured in Hungary for use in amplifiers. I suspect that part of the phase out of vacuum tubes was do really to the view of that being old tech. So there is bound to be some variations of vacuum tubes that still have use.
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