Here is a patent for "tubes on a chip".

http://www.freepatentsonline.com/4721885.html

Long live the tube!

Tony

Love it! I have to go to school, so I don't have too much time to read, but I thought this section sumarized some of the idea. Interesting note I forgot about, regarding how tubes are not really affected by radiation. I heard from someone that the Russians use tubes in their planes and such since they cannot be affected by nuclear bombs. I don't know if they still use tubes or not. Kind of makes the plane heavy!

From the web page:
OBJECTS AND SUMMARY OF THE INVENTION

An object of this invention is the provision of an improved integrated microelectronic device which includes a field emission cathode structure, which device may be readily and inexpensively produced and which operates in the manner of a vacuum tube but without the need for a high vacuum.

An object of this invention is the provision of an improved integrated microelectronic device of the above-mentioned type for use in very high speed integrated circuits which are capable of switching at speeds substantially faster than comparable gallium arsenide devices.

An object of this invention is the provision of an improved integrated microelectronic device of the above-mentioned type which occupies a small space per tube, dissipates a small amount of power in the "on" mode, does not necessitate the use of single-crystal materials, is radiation hard, can be operated over a wide range of temperatures, and may be integrated to contain a large number of circuit elements on a single substrate.

The above and other objects and advantages of this invention are achieved by use of a field emission tube whose dimensions are sufficiently small that the mean free path of electrons travelling between the tube cathode and anode is larger than the interelectrode distances, even at atmospheric or close to atmospheric pressure, say, between 1/100 to atmosphere, and whose voltage of operation is less than the ionization potential of the residual gas. Because a high vacuum is not required for operation, tubes of this type are relatively easily produced, and air or other gases may be employed therein. A variety of circuits may be fabricated using tubes of this invention. For example, high speed memory circuits, may be made wherein tubes are interconnected to provide flip-flop circuits which function as memory elements.

The electromagnetic pulse produced by a nuclear explosion is less damaging to tube circuits but they are still very likely to be affected. Any electronic circuit of any type that is exposed to such a huge magnetic pulse will most certainly go nuts. The amount of current induced in a conductor by a changing magnetic field is proportional to how fast the field changes. The pulse from a nuclear explosion is very fast and very very big. Even short wires in such a field will develop large currents. When those currents have no place to go, large voltages are developed. You get arcs and fried transistors. In tube circuits the tube may survive the arcing but any operating circuit is going to malfunction, at least temporarily.

Tony

:Love it! I have to go to school, so I don't have too much time to read, but I thought this section sumarized some of the idea. Interesting note I forgot about, regarding how tubes are not really affected by radiation. I heard from someone that the Russians use tubes in their planes and such since they cannot be affected by nuclear bombs. I don't know if they still use tubes or not. Kind of makes the plane heavy!
:
:From the web page:
:OBJECTS AND SUMMARY OF THE INVENTION
:
:An object of this invention is the provision of an improved integrated microelectronic device which includes a field emission cathode structure, which device may be readily and inexpensively produced and which operates in the manner of a vacuum tube but without the need for a high vacuum.
:
:An object of this invention is the provision of an improved integrated microelectronic device of the above-mentioned type for use in very high speed integrated circuits which are capable of switching at speeds substantially faster than comparable gallium arsenide devices.
:
:An object of this invention is the provision of an improved integrated microelectronic device of the above-mentioned type which occupies a small space per tube, dissipates a small amount of power in the "on" mode, does not necessitate the use of single-crystal materials, is radiation hard, can be operated over a wide range of temperatures, and may be integrated to contain a large number of circuit elements on a single substrate.
:
:The above and other objects and advantages of this invention are achieved by use of a field emission tube whose dimensions are sufficiently small that the mean free path of electrons travelling between the tube cathode and anode is larger than the interelectrode distances, even at atmospheric or close to atmospheric pressure, say, between 1/100 to atmosphere, and whose voltage of operation is less than the ionization potential of the residual gas. Because a high vacuum is not required for operation, tubes of this type are relatively easily produced, and air or other gases may be employed therein. A variety of circuits may be fabricated using tubes of this invention. For example, high speed memory circuits, may be made wherein tubes are interconnected to provide flip-flop circuits which function as memory elements.
:

My previous post was based pretty much on my intuition and experience as an electrical engineer. The following link seems to be a little more versed:

http://www.geocities.com/CapeCanaveral/5971/emp.html

It looks like I am a little off in my guesstimate of the strength of the field. Short wires probably won't be affected. The conductors have to be fairly long. The article claims that localized heating is what destroys the semiconductor devices. Tubes would be fairly immune to that. But the field strength of 10000 volts per meter is still going to do some zapping, even in a tube circuit.

Tony

:Love it! I have to go to school, so I don't have too much time to read, but I thought this section sumarized some of the idea. Interesting note I forgot about, regarding how tubes are not really affected by radiation. I heard from someone that the Russians use tubes in their planes and such since they cannot be affected by nuclear bombs. I don't know if they still use tubes or not. Kind of makes the plane heavy!
:
:From the web page:
:OBJECTS AND SUMMARY OF THE INVENTION
:
:An object of this invention is the provision of an improved integrated microelectronic device which includes a field emission cathode structure, which device may be readily and inexpensively produced and which operates in the manner of a vacuum tube but without the need for a high vacuum.
:
:An object of this invention is the provision of an improved integrated microelectronic device of the above-mentioned type for use in very high speed integrated circuits which are capable of switching at speeds substantially faster than comparable gallium arsenide devices.
:
:An object of this invention is the provision of an improved integrated microelectronic device of the above-mentioned type which occupies a small space per tube, dissipates a small amount of power in the "on" mode, does not necessitate the use of single-crystal materials, is radiation hard, can be operated over a wide range of temperatures, and may be integrated to contain a large number of circuit elements on a single substrate.
:
:The above and other objects and advantages of this invention are achieved by use of a field emission tube whose dimensions are sufficiently small that the mean free path of electrons travelling between the tube cathode and anode is larger than the interelectrode distances, even at atmospheric or close to atmospheric pressure, say, between 1/100 to atmosphere, and whose voltage of operation is less than the ionization potential of the residual gas. Because a high vacuum is not required for operation, tubes of this type are relatively easily produced, and air or other gases may be employed therein. A variety of circuits may be fabricated using tubes of this invention. For example, high speed memory circuits, may be made wherein tubes are interconnected to provide flip-flop circuits which function as memory elements.
:

Taking into consideration, too, that even regular transistors (discrete) are microscopic internally when compared to regular tubes. It is understandable why they can be fried by the electromagnetic wave created by a nuclear bomb. Considering, now, that these micro-tubes are far smaller than your common transistor, I would think that they'd be just as susceptable to frying.

Hmmm....maybe not the cure-all. We need to go back to the old ST and baloon style tubes. Let's make our computers with those. They're beautiful and rugged!

Thomas

Thomas, They actually made a motherboard with one tube for the audio. It was made by AOpen. Here's a link to it: http://yahoo.pcworld.com/yahoo/article/0,aid,106388,00.asp
I doubt one tube in the audio chain will make much of a difference in sound but it is an interesting idea. Along the same line, I remember a friend sending me an article from a stereo magazine from the mid 1990's for a Luxman amplifier. It was all solid state, probably with conventional bi-polar transistors but with a single 6CG7/6FQ7 in the audio chain. They even mounted it unshielded right behind the front panel with a clear opening to show the one tube off. I doubt it made much difference in sound but was neat to see.
Along with your tubes in computer idea, I am looking for a book I have here which I got at a ham radio club meeting and details the tube linup for ENIAC at the University of Pennsylvania. It not only describes the functions of each but gives a probability of failure for each type. Most were common types like 6SN7's, 5U4's etc. When I find the book, I will post it.

Fred WA3KIO

:Taking into consideration, too, that even regular transistors (discrete) are microscopic internally when compared to regular tubes. It is understandable why they can be fried by the electromagnetic wave created by a nuclear bomb. Considering, now, that these micro-tubes are far smaller than your common transistor, I would think that they'd be just as susceptable to frying.
:
:Hmmm....maybe not the cure-all. We need to go back to the old ST and baloon style tubes. Let's make our computers with those. They're beautiful and rugged!
:
:Thomas

When you consider that 10,000 volts per meter is really only 10 volts per millimeter, it's not that brutal. Even closely spaced vacuum tubes can easily tolerate that. MOSFET gates are spaced in tens of nanometers and can support only a few volts before breakdown. The other problem with semiconductors is that nuclear radiaton bombards them with particles that actually change the doping and, therefore, the electrical characteristics. We used to x-ray JFETs at Siliconix to see if the chips were correctly soldered to the packages. We found that each x-ray shifted the threshold voltage of the device.
Rich

:Thomas, They actually made a motherboard with one tube for the audio. It was made by AOpen. Here's a link to it: http://yahoo.pcworld.com/yahoo/article/0,aid,106388,00.asp
:I doubt one tube in the audio chain will make much of a difference in sound but it is an interesting idea. Along the same line, I remember a friend sending me an article from a stereo magazine from the mid 1990's for a Luxman amplifier. It was all solid state, probably with conventional bi-polar transistors but with a single 6CG7/6FQ7 in the audio chain. They even mounted it unshielded right behind the front panel with a clear opening to show the one tube off. I doubt it made much difference in sound but was neat to see.
:Along with your tubes in computer idea, I am looking for a book I have here which I got at a ham radio club meeting and details the tube linup for ENIAC at the University of Pennsylvania. It not only describes the functions of each but gives a probability of failure for each type. Most were common types like 6SN7's, 5U4's etc. When I find the book, I will post it.
:
:Fred WA3KIO
:
::Taking into consideration, too, that even regular transistors (discrete) are microscopic internally when compared to regular tubes. It is understandable why they can be fried by the electromagnetic wave created by a nuclear bomb. Considering, now, that these micro-tubes are far smaller than your common transistor, I would think that they'd be just as susceptable to frying.
::
::Hmmm....maybe not the cure-all. We need to go back to the old ST and baloon style tubes. Let's make our computers with those. They're beautiful and rugged!
::
::Thomas

Very cool. I'd like to know, however, why every modern electronics geek seems to think that tubes need replacing every two years. How many people who watch their televisions for at least four hours a day replace their picture tube every two years? My parents are still using a microwave that they purchased in August of 1985. It has its original tube. Ah, the lies of advertisement of yesteryear have stuck with us. Buy a solid state radio and forget about those darn tubes that burn out all the time. Yeah, sure. Well, to-day's advertisements aren't any more honest. And then you can go way back to Chevrolet's 1946 "Let's go for a 200,000 mile trip," with an engine that utilized splash lubrication and needed a ring job at only 90,000 miles. Lord help you if you took that 200,000 mile trip at anything over 60. You'll burn out the bearings!

It just bugs me whenever I hear someone say that tubes burn out all the time.

Thomas

I have many tubes in my collection from the 20's, 30's, and 40's with dated test labels on them and those tubes still test like new. I am sure they have many hours of use on them and they will supply many more for sure. I never replace a tube unless it has a problem, even tubes that test weak will still work in most radio circuits. Watch for shorts, they can cause other problems. One 47 tube that was in a Philco set I have tests like brand new but will not work in any radio that uses a 47, strange !

:Very cool. I'd like to know, however, why every modern electronics geek seems to think that tubes need replacing every two years. How many people who watch their televisions for at least four hours a day replace their picture tube every two years? My parents are still using a microwave that they purchased in August of 1985. It has its original tube. Ah, the lies of advertisement of yesteryear have stuck with us. Buy a solid state radio and forget about those darn tubes that burn out all the time. Yeah, sure. Well, to-day's advertisements aren't any more honest. And then you can go way back to Chevrolet's 1946 "Let's go for a 200,000 mile trip," with an engine that utilized splash lubrication and needed a ring job at only 90,000 miles. Lord help you if you took that 200,000 mile trip at anything over 60. You'll burn out the bearings!
:
:It just bugs me whenever I hear someone say that tubes burn out all the time.
:
:Thomas

What does the #47 do that it won't work? Usually output tubes give something, especially if they test new. If they're weak or are on replace, they at least emit some distorted sound. This one just won't work? Perhaps something is disconnected in the base or internally. Perhaps even a wire broke in the base. If you are using an emissions tester, remember that these usually tie all of the grids (save the supressor grid if it's connected internally to the cathode) and the plate together. Because of this you'll get an emission reading regardless of whether all of the elements are connected or not. If the control grid or plate are disconnected somehow, the tube will test good but it won't work. If the plate is disconnected, it won't even affect the reading much, since it is so far away from the cathode. The control grid, on the other hand, should affect the reading greatly. You can try this on your tester. If you have a tester like the EICO 625, with the throw levers that correspond to each pin, throw the plate lever to the filament or return side (with the EICO, up is for the meter--where you put the grids and plates, center is for one side of the filament, and down is the return for the filament and for everything else....you can't really say that up is positive and down is negative because the tester feeds the tube elements alternating current). You will notice very little change in the meter reading when you throw the plate lever to some other position. If you wish to test elements to see if one is failing, throw all levers (plate and grids) to the common position. Then throw up one at a time to see if each is working. You will get a meter reading for each element, even if only small (say for the plate). If you are ever testing a tube that uses a voltage higher than 12 volts, never throw unwanted elements to the filament position because the filament current will flow through them to the cathode, and will cause damage.

I agree that replacing tubes for no reason is bad practice. I only replace weak output tubes if I desire more power and the weak one won't give it. Even then I save the weak tubes for some other purpose (say, a radio which doesn't deliver much power anyway).

Thomas

:I have many tubes in my collection from the 20's, 30's, and 40's with dated test labels on them and those tubes still test like new. I am sure they have many hours of use on them and they will supply many more for sure. I never replace a tube unless it has a problem, even tubes that test weak will still work in most radio circuits. Watch for shorts, they can cause other problems. One 47 tube that was in a Philco set I have tests like brand new but will not work in any radio that uses a 47, strange !
:
:
::Very cool. I'd like to know, however, why every modern electronics geek seems to think that tubes need replacing every two years. How many people who watch their televisions for at least four hours a day replace their picture tube every two years? My parents are still using a microwave that they purchased in August of 1985. It has its original tube. Ah, the lies of advertisement of yesteryear have stuck with us. Buy a solid state radio and forget about those darn tubes that burn out all the time. Yeah, sure. Well, to-day's advertisements aren't any more honest. And then you can go way back to Chevrolet's 1946 "Let's go for a 200,000 mile trip," with an engine that utilized splash lubrication and needed a ring job at only 90,000 miles. Lord help you if you took that 200,000 mile trip at anything over 60. You'll burn out the bearings!
::
::It just bugs me whenever I hear someone say that tubes burn out all the time.
::
::Thomas

Its does play though it is extremely distorted, I suspect a bad solder connection or broken wire in the base. I keep all of my weak tubes as well, when the day comes that a person cant get any more a weak one will be better than none.
Greg

:What does the #47 do that it won't work? Usually output tubes give something, especially if they test new. If they're weak or are on replace, they at least emit some distorted sound. This one just won't work? Perhaps something is disconnected in the base or internally. Perhaps even a wire broke in the base. If you are using an emissions tester, remember that these usually tie all of the grids (save the supressor grid if it's connected internally to the cathode) and the plate together. Because of this you'll get an emission reading regardless of whether all of the elements are connected or not. If the control grid or plate are disconnected somehow, the tube will test good but it won't work. If the plate is disconnected, it won't even affect the reading much, since it is so far away from the cathode. The control grid, on the other hand, should affect the reading greatly. You can try this on your tester. If you have a tester like the EICO 625, with the throw levers that correspond to each pin, throw the plate lever to the filament or return side (with the EICO, up is for the meter--where you put the grids and plates, center is for one side of the filament, and down is the return for the filament and for everything else....you can't really say that up is positive and down is negative because the tester feeds the tube elements alternating current). You will notice very little change in the meter reading when you throw the plate lever to some other position. If you wish to test elements to see if one is failing, throw all levers (plate and grids) to the common position. Then throw up one at a time to see if each is working. You will get a meter reading for each element, even if only small (say for the plate). If you are ever testing a tube that uses a voltage higher than 12 volts, never throw unwanted elements to the filament position because the filament current will flow through them to the cathode, and will cause damage.
:
:I agree that replacing tubes for no reason is bad practice. I only replace weak output tubes if I desire more power and the weak one won't give it. Even then I save the weak tubes for some other purpose (say, a radio which doesn't deliver much power anyway).
:
:Thomas
:
::I have many tubes in my collection from the 20's, 30's, and 40's with dated test labels on them and those tubes still test like new. I am sure they have many hours of use on them and they will supply many more for sure. I never replace a tube unless it has a problem, even tubes that test weak will still work in most radio circuits. Watch for shorts, they can cause other problems. One 47 tube that was in a Philco set I have tests like brand new but will not work in any radio that uses a 47, strange !
::
::
:::Very cool. I'd like to know, however, why every modern electronics geek seems to think that tubes need replacing every two years. How many people who watch their televisions for at least four hours a day replace their picture tube every two years? My parents are still using a microwave that they purchased in August of 1985. It has its original tube. Ah, the lies of advertisement of yesteryear have stuck with us. Buy a solid state radio and forget about those darn tubes that burn out all the time. Yeah, sure. Well, to-day's advertisements aren't any more honest. And then you can go way back to Chevrolet's 1946 "Let's go for a 200,000 mile trip," with an engine that utilized splash lubrication and needed a ring job at only 90,000 miles. Lord help you if you took that 200,000 mile trip at anything over 60. You'll burn out the bearings!
:::
:::It just bugs me whenever I hear someone say that tubes burn out all the time.
:::
:::Thomas

When that day comes, it'll be one sad day! Someone better get out there and make reproduction old style tubes. Those GT style replacements for the ST tubes are kind of sad. Who wants to put a tubular 80 in their radio? I have found, though, that removing the tubular 80 from its 4 pin base and putting it on the narrow octal base makes a really neat and old fashioned looking 5Y3, kind of like the old 117Z6G which is so tall.

Thomas

:Its does play though it is extremely distorted, I suspect a bad solder connection or broken wire in the base. I keep all of my weak tubes as well, when the day comes that a person cant get any more a weak one will be better than none.
:Greg
:
::What does the #47 do that it won't work? Usually output tubes give something, especially if they test new. If they're weak or are on replace, they at least emit some distorted sound. This one just won't work? Perhaps something is disconnected in the base or internally. Perhaps even a wire broke in the base. If you are using an emissions tester, remember that these usually tie all of the grids (save the supressor grid if it's connected internally to the cathode) and the plate together. Because of this you'll get an emission reading regardless of whether all of the elements are connected or not. If the control grid or plate are disconnected somehow, the tube will test good but it won't work. If the plate is disconnected, it won't even affect the reading much, since it is so far away from the cathode. The control grid, on the other hand, should affect the reading greatly. You can try this on your tester. If you have a tester like the EICO 625, with the throw levers that correspond to each pin, throw the plate lever to the filament or return side (with the EICO, up is for the meter--where you put the grids and plates, center is for one side of the filament, and down is the return for the filament and for everything else....you can't really say that up is positive and down is negative because the tester feeds the tube elements alternating current). You will notice very little change in the meter reading when you throw the plate lever to some other position. If you wish to test elements to see if one is failing, throw all levers (plate and grids) to the common position. Then throw up one at a time to see if each is working. You will get a meter reading for each element, even if only small (say for the plate). If you are ever testing a tube that uses a voltage higher than 12 volts, never throw unwanted elements to the filament position because the filament current will flow through them to the cathode, and will cause damage.
::
::I agree that replacing tubes for no reason is bad practice. I only replace weak output tubes if I desire more power and the weak one won't give it. Even then I save the weak tubes for some other purpose (say, a radio which doesn't deliver much power anyway).
::
::Thomas
::
:::I have many tubes in my collection from the 20's, 30's, and 40's with dated test labels on them and those tubes still test like new. I am sure they have many hours of use on them and they will supply many more for sure. I never replace a tube unless it has a problem, even tubes that test weak will still work in most radio circuits. Watch for shorts, they can cause other problems. One 47 tube that was in a Philco set I have tests like brand new but will not work in any radio that uses a 47, strange !
:::
:::
::::Very cool. I'd like to know, however, why every modern electronics geek seems to think that tubes need replacing every two years. How many people who watch their televisions for at least four hours a day replace their picture tube every two years? My parents are still using a microwave that they purchased in August of 1985. It has its original tube. Ah, the lies of advertisement of yesteryear have stuck with us. Buy a solid state radio and forget about those darn tubes that burn out all the time. Yeah, sure. Well, to-day's advertisements aren't any more honest. And then you can go way back to Chevrolet's 1946 "Let's go for a 200,000 mile trip," with an engine that utilized splash lubrication and needed a ring job at only 90,000 miles. Lord help you if you took that 200,000 mile trip at anything over 60. You'll burn out the bearings!
::::
::::It just bugs me whenever I hear someone say that tubes burn out all the time.
::::
::::Thomas