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On Wed, 25 Feb 2004 23:41:36 GMT, "Frank Dresser"
wrote: "harry" wrote in message om... Hi Folks: A guy at work bought his old guitar amp to get looked at. The tech said he needed new tubes. (probably really doesn't). However, I needed to bring in my 833A and said he needed 2 tubes like this!! He was hysterical! The tech and I got talking about BIG glass tubes. I was wondering if anyone knows of a bigger glass tube than 833a , 852 , 861, 4-1000a etc. Thanks! Harry These are pretty big. They're described as 5 feet tall. They're from Powel Crosley's 500 kw WLW transmitter: http://hawkins.pair.com/wlw/wlw3.jpg This is from: http://hawkins.pair.com/wlw.shtml Good Gawd, but that is a terrible page to try to read after they load the background! Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com Frank Dresser |
Roger Halstead wrote:
OTOH, there are many tubes in the multi KW range that are Huge. I've seen pictures of "walk in" tubes that had an air lock. If you ever find those pics, _PLEASE_ scan them and put them up on a website somewhere, or mail the scanned images to me so that I can put them on mine. -- Mike Andrews Tired old sysadmin |
On Sun, 29 Feb 2004 05:22:45 +0000 (UTC), (Mike
Andrews) wrote: Roger Halstead wrote: OTOH, there are many tubes in the multi KW range that are Huge. I've seen pictures of "walk in" tubes that had an air lock. If you ever find those pics, _PLEASE_ scan them and put them up on a website somewhere, or mail the scanned images to me so that I can put them on mine. "I believe" it was the old VOA station. "It seems" like there was a story on it wayyyy back in QST. Maybe in the 60s or 70s. OTOH it could have been one of the very high powered VLF stations. At least those are a couple of good places to start. I remember the photo, but it's been a long time. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com |
In article , Roger Halstead
writes: OTOH, there are many tubes in the multi KW range that are Huge. I've seen pictures of "walk in" tubes that had an air lock. "I believe" it was the old VOA station. "It seems" like there was a story on it wayyyy back in QST. Maybe in the 60s or 70s. OTOH it could have been one of the very high powered VLF stations. At least those are a couple of good places to start. Most likely you are remembering the plate coil and capacitor output network of one of the old Navy VLF stations. I remember photos of a big room full of the inductor and some capacitors that looked like they'd hopped off telephone poles. The room had copper plated walls and an interlock on the door to cut the juice if someone opened it. I doubt there were ever walk-in tubes. The vacuum required for any kindof tube life is so "hard" and pure that you wouldn't be able to pump out a whole room to that purity. Though maybe with a really big "getter" ... Mike K. Oscar loves trash, but hates Spam! Delete him to reply to me. |
Mike Knudsen wrote:
I doubt there were ever walk-in tubes. The vacuum required for any kindof tube life is so "hard" and pure that you wouldn't be able to pump out a whole room to that purity. Though maybe with a really big "getter" ... Mike K. I have this image of someone walking in through the airlock with a _big_ container of cesium or strontium, to be used as a getter, and hooking it up to a pair of terminals on the inside of the tube once it has been baked and pumped down for a while. I also have this image of an enormous induction heater, with coils completely surrounding the tube, forepumps the size of modern fanjet engines, and diffusion pumps slinging kiloliters of oil per second. Somehow, I think it's just not viable. -- I just overheard someone referring to Solaris 2.6 as a "virgin operating system". With a straight face, no less. In one sense, I can see it. The one whereby it knows what it wants to do, it's just not entirely sure how... -- Carl Jacobs |
In article ,
Mike Andrews wrote: Mike Knudsen wrote: I doubt there were ever walk-in tubes. The vacuum required for any kindof tube life is so "hard" and pure that you wouldn't be able to pump out a whole room to that purity. Though maybe with a really big "getter" ... Mike K. I have this image of someone walking in through the airlock with a _big_ container of cesium or strontium, to be used as a getter, and hooking it up to a pair of terminals on the inside of the tube once it has been baked and pumped down for a while. I also have this image of an enormous induction heater, with coils completely surrounding the tube, forepumps the size of modern fanjet engines, and diffusion pumps slinging kiloliters of oil per second. Somehow, I think it's just not viable. I believe that in Rocket Ship Galileo, Heinlein discussed vacuum tubes on the moon. No external envelope needed, just shielding. --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
Scott Dorsey wrote:
I believe that in Rocket Ship Galileo, Heinlein discussed vacuum tubes on the moon. No external envelope needed, just shielding. He did. Should make for _great_ transmitting-tube laboratories. -- There are two product lines in which customers are called "users". The other one is illegal drugs. MWMeyer, viva voce personal communication |
Mike Knudsen wrote: I doubt there were ever walk-in tubes. The vacuum required for any kindof tube life is so "hard" and pure that you wouldn't be able to pump out a whole room to that purity. Though maybe with a really big "getter" ... Mike K. I don't know about walk in tubes but I do recall visiting a UK Post Office radio station many years ago and walking into the final amplifier where there was at least one tube which I recall as being around 4 or 5 feet high (maybe more) which had a water cooling system. If it means anything to anyone the station was at Leafield in Oxfordshire. Dave |
On Wed, 03 Mar 2004 22:47:32 -0500, Dave Holford
wrote: Mike Knudsen wrote: I doubt there were ever walk-in tubes. The vacuum required for any kindof tube life is so "hard" and pure that you wouldn't be able to pump out a whole room to that purity. Though maybe with a really big "getter" ... Mike K. It's not that difficult. Where I used to work we had vacuum chambers large enough for to get in. We ran those down to 10^-7 torr. OTOH we had some mass spectrometers that used ion pumps in addition to the mechanical roughing pumps and the diffusion pumps. Once past about 10^-2 torr, most of the molecules cling to the surfaces and are basically scrapped off with the diffusion pumps. After that there isn't a lot for the ion pumps as the things lasted for years. Course if we managed to burn out one of the induction heating coils which was water cooled, it took days to clean up the mess. You know it's gonna be a bad day whey there is water coming out the roughing pump exhaust. We once had a failure on the midnight shift that wasn't caught right away. It filled up the entire exhaust system for a big room full of float zone refining equipment. Now that was expensive. Roger Halstead (K8RI & ARRL life member) (N833R, S# CD-2 Worlds oldest Debonair) www.rogerhalstead.com I don't know about walk in tubes but I do recall visiting a UK Post Office radio station many years ago and walking into the final amplifier where there was at least one tube which I recall as being around 4 or 5 feet high (maybe more) which had a water cooling system. If it means anything to anyone the station was at Leafield in Oxfordshire. Dave |
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