Vacuum Tubes?


Not a radiotelecommunications expert here, but I believe that very high-powered broadcast equipment still uses vacuum tubes.

Not the little tubes shown in the picture, the kind that were used in antique radio receivers and telebishion sets. Giant high-voltage amplifier tubes, tubes that probably cost thousands of dollars each.
Although $37 billion does sound stunningly high.
I noticed this and thought it seemed really high too. The Wikipedia entry notes they are still used in some telecommunication equipment, but that in most applications have been phased out in favor of other technology. Also, who talks about vacuum tubes? We hear about aircraft and auto sales, fuel prices, etc., all the time, but vacuum tubes are not in the public consciousness. If they are consistently among our top five exports, why don't we hear more about them? Very strange.
I bet it's related to maintenance of the war machines.

Remember the goal: sell the razorblades, not the razor.
Reminds me: I need a new Klystron tube for my Interocitor.
@3 politicians don't talk about the price of vacuum tubes does not directly effect voters or consumers.
My parents had a TV with real, actual vacuum tubes back in the early 1970s. I've never seen one since then.
they are used to generate the whole range of electromagnetic radiation, e,g, microwaves…
I think that's a euphemism for bullets.
Ask your musician friends. Tubes rule the musical world!
It looks like super-high-tech vacuum tubes are used in radar and other millimeter-wave transmitters. According to this article
The armed forces use the devices in
transmitters for the detection of small targets and target imaging, in radar equipment, communications and
smart weapons systems. In the commercial sector the
amplifiers are widely used in high-data-rate communication systems such as digital radio links, SATCOM
and wireless LAN, while the consumer market is
expected to turn to millimeter-wave systems for applications such as automotive radar
@11, not at $37 billion exports they don't. And most tubes for your rockin' Fender Twin Reverb amps and whatnot don't get exported at all.
Here's another one: many advanced solar collectors use vacuum tubes.
Are they counting CRTs as vacuum tubes? They are, after all, though slightly outside the common usage of the term. And $37 billion would still be a surprising amount for CRTs these days!
$37B of vacuum tubes is preposterous. It's probably a category that includes semiconductors. What shoddy reporting by Times/AP
Perhaps for a Transducer.
I wonder if the AP copyeditor mistakenly truncated a longer category name, along the lines of "Vacuum tubes, radio, semiconductor, and computer equipment". Eimac is still in business, and still in the U.S., but they're not exactly Intel-sized.
Have you ever gone to Steve's Old Technology shop up on Aurora?

I used to visit there and buy things (just because they looked cool). If they are still around, they used to have tubes.

Back in the 1960s growing up, I remember the hardware stores used to have "tube testors". Kind of a breadboard thing with numbered slots for home repairmen that wanted to test and replace tubes in their radios and tvs.

Post transistor, tubes were still considered by audiophiles to make superior receivers. I do not know if that still is the case.
I went on a similar web-research ramble recently when I found a very old-looking "Edison Mazda" (early GE trademark) lightbulb—that worked!—in a box of things that had been in a relative's home. I was able to date it to 1913-1919 because they stopped using carbon filaments after 1912 (mine had tungsten) and they stopped putting the little gas-evacuation nipple on the top of the bulb after 1919 (they began sucking the air out via the bottom, through the filament pedestal, before attaching the brass screw base.

Interestingly, you can get accurate reproductions of these old lamps if you have a historic home or an old railroad car or just an old table lamp (1/3 the light for 10 times the price!):

Regarding vacuum tubes, if I remember correctly, if you want the small garden-variety tubes for your mid-century table radio or Hammond organ, compatible replacements are still made in Russia.

Fnarf @14, I think that might refer to the long double-wall tubes used in parabolic solar collectors like these—the inner tube contains an oil that is used as a heat-transfer fluid for the steam generators (because it can get very hot without creating pressure on the system) and the outer tube has a vacuum to prevent excessive heat loss to the air. Unless maybe they use some kind of vacuum-tube diode for inverters, to convert solar-cell DC to AC. But there are probably more-efficient high-power solid-state solutions for those.
Nicholas @18: Your's seems to be the most likely explanation offered thus far. I know there are some modern uses for vacuum tubes, but I can't see how any of them add up to $37 billion a year.
I wonder if in the entire history of the vacuum tube consuming world $37 million of the things were ever produced for all uses combined.

I hope the fuel exports were not used in US military aircraft,ships and armored vehicles that I also hope were not major components of a couple of the other categories.
Vacuum tubes are also less prone to getting fried in sensitive electronic applications unlike solid state technology. My guess is that a surprising amount of military hardware still uses tubes to defend against it being incapacitated by an EMP generated by a nuclear attack.

Also, the recording and broadcasting industry is probably bigger than you're accounting for, Goldy.
Hawthorne Stereo in Roosevelt
They must have offloaded the repair, with parts, of used equipment to Elbonia

I think it is a broad catagory, too, just as "fuel" might include coal.
I wonder if in the entire history of the vacuum tube consuming world $37 million of the things were ever produced for all uses combined.

I hope the fuel exports were not used in US military aircraft,ships and armored vehicles that I also hope were not major components of a couple of the other categories.
I spend a couple hundred a year on tubes for my guitar amps. I assume everyone else does the same.
@16/18, that sounds like the most likely thing to me. Unless there is some staggeringly obscure yet widespread military use for something that could be considered 'vacuum tubes,' I'm betting it's a larger category that includes other circuitry/computer/silicon components.

As far as vacuum tubes for electronics go (audio nerds), most of those are coming from russia and eastern europe. Some new, some new old stock. Even if CRTs fit in that category, they've been dead for years, even for flight simulators and cockpit displays. There are a few small-outfit companies still servicing and manufacturing CRT tubes (usually small ones or projection tubes, not TV-sized ones) but they're fairly small-fry and still stuck in the 1990s, apparently:…
Stacks and stacks of amps for the GODS OF MET-UHL!!!
Vacuum tubes operate well in extremely hot environments. Solid state devices do not. The Middle East is a hot environment.
@28: I have terrible news for you.
I don't think it would take very many of the very expensive tubes used for OTA radio/TV/etc. broadcasting to add up to $28 mil.
@30 OMG! Noooooo!!!
By the way, nerd props @6.

"This isn't paper, it's some kind of metal!"
The short answer is that 95% of the world doesn't have the level of technology we do.
Dont confuse electron tubes with vacuum tubes used in industry, medical labs and elsewhere....those have no electronic elements involved.
Steve is still in business!! The Shop
On Aurora is long gone but he still has his 20,000 vacuum tubes.

I'm so glad someone mentioned it and I tried the number on the off chance the business is still around (as is com-pro-sof although it's storefront is also gone).

Personally I was more likely to buy a slide-rule than a tube but it sure is a good thing to know old stuff can be repaired!

This made my day!
@21 that seems right. The biggest dollar vacuum tube industries are xrays, microwave, and other high energy applications. Only the really tricky high-end tubes are made here. China and korea e.g. make most magnetrons for microwaves. But things like replacement CAT scan tubes and such can't total more than 4-5Bn, but probably more like 1-2Bn.
Last I heard, tubes for audiophile equipment were coming from Russia, which was the only place they were still manufactured. I might be wrong about that.

@1 might be on to something. Once upon a time, I worked at an aerospace contractor that did vibration testing of big things. To do it, they used giant electromagnetic "shakers" that were powered by very high-wattage audio amplifiers. The big one was 250,000 watts and used a bunch of big, honking air-cooled triodes weighing over 50 pounds each. I know, because I had to go into the amplifier to change them.

Here's a water-cooled version of something similar.
@34 I would also like to register my approval of #6. Even one triangular viewing screen that cannot be photographed must be worth at least $37billion.
@39 -Lots of mid-grade tubes are made in Russia. Tung-sol, Sovtek, Svetlana (my personal favs for Fender amps), Winged C. But the very high end are us/uk, although some of us gear nerds spend the $ for NOS.

Depends on the style of tube and amp, but there are some great ones out there. Bell from India made a nice el84, (and cathode biased amps like the AC30 can take mismatched pairs, without rebiasing, -what are the chanced of finding a matched quad?) Mullard made great el34s and kt66s. Milspec often go by different codes, and can be confusing, but those are great for an amp that is gonna rattle around in the back of a van for a couple thousand miles. Preamp tubes are a whole different ballgame.
All the way up until the early 80's (and perhaps later) air intercept defense for the West Coast was run on two giant vacuum tube computers housed in a building at McChord Air Force Base. My scout troop got to tour the facility.

They would run one for 12-24 hours then switch over to the other in order to replace tubes. The building had cooling towers behind to dump all the excess heat.
My nerd hairs are standing on end. @42, kmg1, what did it look like?.
Oh! is this it? Only half of the vacuum tubes are shown.


These people claim they have a 12 million tube inventory at their radio electric supply store for "Amateur Radio, Industrial Equipment, Amplifiers of all kinds, Sound Equipment, Transmitters, Antique Radio, Electronic Organs, CB Radios, Ham Radio and more!".
Vacuum tubes are still used for lots of very high power RF, especially in the upper microwave region. They are also used in applications like inductive heating which need RF at powers of tens or hundreds of kW.

OK, since Goldy, Ace Boy Reporter, can't be bothered to, um, look at the publicly available source of the story he's reblogging:

85.40 - Thermionic, cold cathode or photocathode tubes (for example, vacuum or vapor or gas filled tubes, mercury arc rectifying tubes, cathode-ray tubes, television camera tubes); parts thereof:"

So yeah, 'vacuum tubes' includes CRTs.
The two tube powered machines @ McChord were reliable. I got a tour in high school. Each took up a building floor. They were designed knowing that stuff fails (spare cycles were used for testing, all the tube circuits were on fast change racks, a large staff 24x7 replacing stuff as needed or scheduled, tubes @ low current to minimize burnout, etc.). I saw darn near every technology between 1955 with the possible exception of mercury delay lines to the then date plugged into the thing including a panel usually only seen in Irwin Allen SciFi shows. Even had light pens...well, they were the size and weight of electric drills, but you could query stuff on the screens interactively with them.

When they were finally replaced the News-Tribune reported the new machines (size of a coke machine) were purchased using the A/c budget they no longer needed much of.

Just amazing all things considered.

Maybe "Vacumn Tubes" is Short Talk for Illegal Laundry of US Paper Money DOLLARS $$$$$$$$$$$$$$$ WHAT DO YOU THINK?????


RON IN TEXAS ON 1-1-2012 12 NOON.
@50: An interesting theoretical construct, sir.
Rock and Roll!
Take a look at the U.S. Census Bureau definition of code 334411. The title of the export category would have been more descriptive as "Electronic Tubes". Lots of different applications.
Look you guys, lots of audio equipment, such as guitar amps, mike preamps for recording, and high-end stereos, still use vacuum tubes, because they sound great. In recent years, most production was in China, Russia, and other eastern European countries, because their environmental rules were more lax. They still use tubes in military electronics in Russia, China, North Korea, etc.
I knew there were some high-end tubes for guitar amps and such made here, and that Peavy makes tubes in Mississippi, but still I'm suprised at the number.
Lots of industrial applications for heavy-duty vacuum tubes too. High voltage power supplies. Magnetrons used in sputter deposition systems: if you own a piece of plastic with a metal film on it, that's what put it there. Camera and eyeglass lenses have all been through one. Every silicon chip fab in the world has half a dozen of the things, and at $10k to $50k a pop, it adds up fast. Every radio station in the world has a great big tube driving their transmitting antenna, and a hot spare so they can switch over in seconds if the first burns out.

These tubes are huge. They have big water-cooling jackets and the power cable is the size of your wrist.
We're not exporting $37B in guitar amp tubes. oy. *facepalm*

@55 even at that highest price, you're talking about three-quarters-of-a-MILLION of those 50K tubes going out (or nearly 4 million of them at $10K each)

$37B is a HUGE number.
thanks @48 . under those defintions LIGHT BULBS (including those $300-$2000 ones for film/TV) are also vacuum tubes, so it's starting to make more sense.
10,000 Ampeg SVTs!
hipsters prefer the warmer sound and accurate soundstage produced by tubes, plus they have a lot of discretionary income... so there's that.

Match these numbers with any other list of top exports and if you have half a brain you'll realize "Vacuum tubes" is really "Semiconductors".
We have two full boxes of various tunes by Motorola, Ge, etcetera that we have been trying to sell. We bought them so we could take pictures of them. Email me for a complete list.
Following up on Nicholas @18 I looked at NAICS industry code categories. "electron tube manufacturing" is code 334411. The higher level category 3344 - "semiconductor and other electronic component manufacturing", includes many computer related manufacturing like circuit boards, printed circuit assemblys, semiconductor and related devices.
Seems likely that this category could be one of the top ten.
For the conspiracy theorists: Census reports for 2000 shows vacuum tubes with an NAICS code of 335314. In NAICS documents, this code is "relay and industrial control manufacturing" with other keywords "armature relays manufacturing"
Vacuum tubes also include pharmacutical tubes for drawing blood. The tubes are sealed and evacuuated. These tubes are not cheap and must meet strict specifications and are shipped by the millions. There are also other vacuumed tubes in other fields such a neon-tubes which are vacuumed and then filled with other gases.
Check out… for a list of tube manufacturers.
Vacuum tubes are still used by militaries in some applications because they are not susceptible to the crippling effects of an EMP attack that circuit boards and solid state technologies are. Also many guitarists use tube amps for their electric guitars because they sound better than solid state amps. They are warmer, smoother, and have better dynamics. As a guitarist, i can attest to this.
Probably the anonymus buyers wanna be prepared for the big EMP or solar flares yet to come.

A windmill , a generator ,a vacuum tube transmitter and receiver and voila ! human kind will survive .

And yes, turn off the light and listen some jazz while looking at an old school vacuum tube radio, no mp3 player can beat that !

siincereley ,Gabriel
They are used in industrial heat induction equipment. Also in the medical field for diathermy and MRI's.