# Vacuum tubes **URL:** \ **Category:** Factual Questions\ **Created:** [April 7, 2003, 12:32pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040 "2003-04-07T12:32:37Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Johnny\_L.A](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/johnny_l.a/32/1084_2.png) [@Johnny\_L.A](https://boards.straightdope.com/u/Johnny_L.A)\ **Post date:** [April 7, 2003, 12:32pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/1 "2003-04-07T12:32:37Z")
When I was a kid our TV had vacuum tubes. The radio on my grandmother’s kitchen table had vacuum tubes. Grocery and variety stores had tube testing machines so you could see if a tube needed replacement, and a stock of tubes under it. Friday I was at a mall and went into an antique store. There was a white plastic radio that reminded me of my grandmother’s. I thought it would be neat to buy it, just for the funkiness of having a tube radio (I use a rotary phone frequently). But then I wondered about the tubes. Are vacuum tubes still available? Are they still being made? Or do you have to go to antique stores to find them? Is there some secret cache of vacuum tubes somewhere? ---
**Author:** ![Pergau](https://avatars.discourse-cdn.com/v4/letter/p/7c8e57/32.png) [@Pergau](https://boards.straightdope.com/u/Pergau)\ **Post date:** [April 7, 2003, 12:40pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/2 "2003-04-07T12:40:35Z")
You can still buy vaccum tubes but they are hard to come by. They are still used in some specialist devices (e.g. music amps to give a “warm” sound) but you’d have to check with a specialist electronic shop to get a particular model tube. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [April 7, 2003, 12:41pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/3 "2003-04-07T12:41:57Z")
Yes, they’re still availaible. In fact, there are a very few modern audio amp manufactures who _still_ make lines of tube amps (coveted by many musicians and audiophiles). There is aslo a great deal of old tube ham radio equipment which have been kept running by their operators. Google on “vacuum tube” and you’ll find dozens and dozens of places selling them. As to whether they are still being made, I heard long ago that no new tubes were being manufactured and all the tubes being sold today are being stored by the places that sell them. This sounds like a myth to me, but I’ve never been able to verify it. ---
**Author:** ![stuyguy](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@stuyguy](https://boards.straightdope.com/u/stuyguy)\ **Post date:** [April 7, 2003, 12:44pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/4 "2003-04-07T12:44:30Z")
As of a few years ago I know you could get vt’s from Radio Shack (and I’m pretty sure you still can). Like odd-sized batteries though, they are a special-order item. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [April 7, 2003, 1:10pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/5 "2003-04-07T13:10:07Z")
Can you still buy vacuum tubes used in old computers? If one wanted to recreate the first generation of computers, possibly build some new machines, would it be possible without making certain tubes from scratch? ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [April 7, 2003, 1:11pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/6 "2003-04-07T13:11:57Z")
The army (as of 1996) uses a _huge_ quantity of commercially-available vacuums tubes. It may be that they have “enough” stored for all of remaining history, but I have to imagine that someone, somewhere is manufacturing them. I remember we used a lot of Raytheon brand tubes, but a tube with a certain number was supposed to be identical across brands. Raytheon’s site says they’ve divested all thier tube business to these guys below, so they may still make tubes: [http://www.littonedd.com/](http://www.littonedd.com/) (no page configured comes up) [http://www.cpii.com/bmd/magtable1.htm](http://www.cpii.com/bmd/magtable1.htm) (magnetrons, probably not useful for your receiver!) [http://www.cpii.com/eimac/index.html](http://www.cpii.com/eimac/index.html) (power tubes) Actually, this is a better list: [http://www.worldtubeaudio.com/directory/categories/kategorie\_9.htm](http://www.worldtubeaudio.com/directory/categories/kategorie_9.htm). Seems to be oriented towards radio, which is what you want. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [April 7, 2003, 1:15pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/7 "2003-04-07T13:15:39Z")
Yes, all you need is a tube capable of switching, the way a transistor does. Most tubes used as amplifiers can be used this way. You’ll need a hell of a lot of them, plus a big ass air conditioner, a building to keep it in, and a BIG budget for electricity. It won’t run Windows (though some might consider that a benefit). ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [April 7, 2003, 1:16pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/8 "2003-04-07T13:16:46Z")
That last post was directed at **Derleth**. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [April 7, 2003, 1:24pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/9 "2003-04-07T13:24:52Z")
> [@](#): > > \*Originally posted by Q.E.D. \* > \*\*. . . .I heard long ago that no new tubes were being manufactured and all the tubes being sold today are being stored by the places that sell them. This sounds like a myth to me, but I’ve never been able to verify it. \*\* New tubes are being manufactured and are not difficult to get. However, for musicians, the most coveted tubes are NOS–new old stock. That oxymoron means that these are “vintage” tubes that have never been sold or used, and still test out good as new. I don’t know if the same is true for audiophiles. The tubes are valued by musicians because when they are overdriven they produce harmonic distortion, whereas transistors just make noise. I really don’t know why NOS tubes are so valued, though. In the music business the conventional wisdom is usually, “They don’t make 'em like that anymore.” The world of tubes is a lot like the world of wine. ---
**Author:** ![Derleth](https://avatars.discourse-cdn.com/v4/letter/d/b9e5f3/32.png) [@Derleth](https://boards.straightdope.com/u/Derleth)\ **Post date:** [April 7, 2003, 2:02pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/10 "2003-04-07T14:02:36Z")
**QED** , a lot of the oldest machines didn’t have OSes anyway. You wrote on the bare metal and you liked it. 😃 ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [April 7, 2003, 2:04pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/11 "2003-04-07T14:04:33Z")
A lot of Ham Radio power amplifier tubes are still manufactured new. A lot of the older tubes are found at swap meets. The single tube in our club station’s 4 KW amplifier sell for about $900 U.S. ---
**Author:** ![Berkut](https://avatars.discourse-cdn.com/v4/letter/b/a88e57/32.png) [@Berkut](https://boards.straightdope.com/u/Berkut)\ **Post date:** [April 7, 2003, 2:07pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/12 "2003-04-07T14:07:54Z")
> [@](#): > > \*Originally posted by GaryM \* > **our club station’s 4 KW amplifier** That sure is a big amplifier. 😉 ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [April 7, 2003, 2:14pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/13 "2003-04-07T14:14:06Z")
I’m pretty sure tubes are still used in radio and TV transmitters. While solid state has its advantages, so far no one has come up with a way of producing thousands of watts of RF energy using transistors… Last I heard, regular ‘ol vacuum tubes are still being made in Russia and China. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [April 7, 2003, 2:22pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/14 "2003-04-07T14:22:01Z")
> [@](#): > > \*Originally posted by CookingWithGas \* > **The tubes are valued by musicians because when they are overdriven they produce harmonic distortion, whereas transistors just make noise.** From what I’ve heard (and I’m no expert), tubes are coveted by purists for two reasons: 1. A tube has a gradual cut-off when overdriven, thus producing a “softer” response. Transistors have a sharp cut-off, thereby producing nasty-sounding harmonics. 2. Transistors tend to produce _odd_ harmonics, while tubes tend to produce _even_ harmonics. (At least this is what I’ve _heard_.) According to the purists, odd harmonics sound irritatingly “harsh” and “metallic” while even harmonics sound “soft” and warm.” ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [April 7, 2003, 3:03pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/15 "2003-04-07T15:03:14Z")
Radio Shack most definitely still sells tubes via catalog and online (guess the URL). More expensive than other places though. I buy my tubes at ham fests. Have the business cards for some guys somewhere. There are computer motherboards being sold today that have a tube on them in order to provide higher quality sound. The tubes for these are new. Tubes are apparently still being made in Russia. And then … There are “micro” vacuum tube arrays being built. Think really, really small. Very special built hardware though. For some apps, you just can’t beat tubes. ---
**Author:** ![Flying\_Monk](https://avatars.discourse-cdn.com/v4/letter/f/48db29/32.png) [@Flying\_Monk](https://boards.straightdope.com/u/Flying_Monk)\ **Post date:** [April 7, 2003, 3:04pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/16 "2003-04-07T15:04:31Z")
Tubes sound better, that’s all. Even antique radio guys know this. I’ve known a lot of musicians, and I’ve never heard the NOS bit, although I do know a few folks who’d love to get their hands on a vintage Marshall head. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [April 7, 2003, 3:43pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/17 "2003-04-07T15:43:10Z")
I found these guys, [http://www.tubesandmore.com/](http://www.tubesandmore.com/) when doing some research to build my own tube guitar amp. ---
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [April 7, 2003, 4:00pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/18 "2003-04-07T16:00:39Z")
have heard that vacuum tubes are more resistant to EMP attack than transistors. Is this a good reason for keeping some just in case? ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [April 7, 2003, 4:17pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/19 "2003-04-07T16:17:51Z")
> [@](#): > > \*Originally posted by eburacum45 \* > have heard that vacuum tubes are more resistant to EMP attack than transistors. Is this a good reason for keeping some just in case? You would have to be very close to a likely target of a conventional EMP attack to worry about this. And having just tubes would do most people very little good. An actual working tube radio would be helpful. I have two working tube SW radios made by my father in electronics school in WWII. But I might also need power. My current UPSes wouldn’t supply enough power for a useful period of time. A better idea is to store a radio and batteries in a steel box (preferably grounded). Keep the batteries out of the radio wrapped in plastic. Check on them every once in a while. [This is Dale Gribble level paranoia though.] A nuke can also generate an EMP pulse that would damage electronics over a very wide area. But listening to the radio is fairly far down on the list for most people after a nuke. ---
**Author:** ![GaryM](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/garym/32/241_2.png) [@GaryM](https://boards.straightdope.com/u/GaryM)\ **Post date:** [April 7, 2003, 4:36pm UTC](https://boards.straightdope.com/t/vacuum-tubes/167040/20 "2003-04-07T16:36:51Z")
> [@](#): > > \*Originally posted by Joey G \* > \*\*That sure is a big amplifier. 😉 \*\* Yes it is! It’s a Henry Radio 4K Ultra. $KW input and will produce 2.5 KW out. But we are always careful to not exceed the power required to carryout the desired communication IAW part 97 [Next page](https://boards.straightdope.com/t/vacuum-tubes/167040.md?page=2)