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Ancient circuitry
Here at work, we are repairing the vacuum control circuitry for an
electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. |
Ancient circuitry
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Ancient circuitry
"Del Cecchi" wrote in message ... "Canuck57" wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away ;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. Bu the rest is history. You are a couple of years overdue. Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS at 12 volts worked much better. Vacuum tubes worked perfectly. (and still do). Eisboch |
Ancient circuitry
On Jan 17, 6:18*pm, "Eisboch" wrote:
"Del Cecchi" wrote in message ... "Canuck57" wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch *wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. *It has 6 SN7400 chips. *If I remember, these are quad 2 input NAND gates. *2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. *I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away *;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. *Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. *Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. *A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. *As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. *Bu the rest is history. You are a couple of years overdue. *Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. * The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was *used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. *It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS *at 12 volts worked much better. Vacuum tubes worked perfectly. *(and still do). Eisboch I'd like to find a cool vacuum tube project to make steampunk. |
Ancient circuitry
"Eisboch" wrote in message ... "Del Cecchi" wrote in message ... "Canuck57" wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away ;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. Bu the rest is history. You are a couple of years overdue. Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS at 12 volts worked much better. Vacuum tubes worked perfectly. (and still do). Eisboch TTL up level was 2 volts, down level was 0.8 at the input. The output was 2.4 and .4 for 400 mV of noise immunity. S and LS was a little different. I've still got a TI manual with the gold covers on my bookshelf. Vacuum tubes worked OK for some things if you didn't need long life, reliability, and had plenty of power to waste. If you want to make a solid state amp sound like vacuum tubes, put some resistance in series with the speakers, to simulate the higher output impedence. del |
Ancient circuitry
On Jan 17, 9:08*pm, "Del Cecchi" wrote:
"Eisboch" wrote in message ... "Del Cecchi" wrote in message ... "Canuck57" wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch *wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. *It has 6 SN7400 chips. *If I remember, these are quad 2 input NAND gates. *2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. *I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away *;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. *Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. *Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. *A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. *Bu the rest is history. You are a couple of years overdue. *Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. * The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was *used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. *It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS *at 12 volts worked much better. Vacuum tubes worked perfectly. *(and still do). Eisboch TTL up level was 2 volts, down level was 0.8 at the input. *The output was 2.4 and .4 for 400 mV of noise immunity. S and LS was a little different. *I've still got a TI manual with the gold covers on my bookshelf. Vacuum tubes worked OK for some things if you didn't need long life, reliability, and had plenty of power to waste. * If you want to make a solid state amp sound like vacuum tubes, put some resistance in series with the speakers, to simulate the higher output impedence. del "Tubes" could come back. Imagine a carbon nano-tube as the filament/ cathode. It would emit electrons with a small applied voltage without heating due to "tunnelling" and the extremely high field levels near the tip. It would be inserted into a well in a silicon chip. A ring of conductor is evaporated around the top edges of said well as a grid. A short distance above that would be the anode plane. All of this made on dimensions of a micron or so with zillions of them etched into an Si wafer. Voila, integrated circuitry of "tubes". |
Ancient circuitry
On 17/01/2010 4:09 PM, Del Cecchi wrote:
wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away ;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. Bu the rest is history. You are a couple of years overdue. Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss Has to show up at Best Buy for a mortals price. |
Ancient circuitry
On 17/01/2010 4:18 PM, Eisboch wrote:
"Del wrote in message ... wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away ;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. Bu the rest is history. You are a couple of years overdue. Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS at 12 volts worked much better. Vacuum tubes worked perfectly. (and still do). Eisboch Can't say I miss tubes. RF and heat burns... But good heaters. |
Ancient circuitry
On Jan 18, 8:36*am, Canuck57 wrote:
On 17/01/2010 4:18 PM, Eisboch wrote: "Del *wrote in message ... *wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch * wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. *It has 6 SN7400 chips. *If I remember, these are quad 2 input NAND gates. *2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. *I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away *;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. *Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. *Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. *A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. *As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. *Bu the rest is history. You are a couple of years overdue. *Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. * The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was *used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. *It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS *at 12 volts worked much better. Vacuum tubes worked perfectly. *(and still do). Eisboch Can't say I miss tubes. *RF and heat burns... But good heaters.- Hide quoted text - - Show quoted text - I miss them in my guitar amp! |
Ancient circuitry
In article c9511ebc-d7f2-449a-9d90-c55f2b828712
@m3g2000yqf.googlegroups.com, says... On Jan 18, 8:36*am, Canuck57 wrote: On 17/01/2010 4:18 PM, Eisboch wrote: "Del *wrote in message ... *wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch * wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. *It has 6 SN7400 chips. *If I remember, these are quad 2 input NAND gates. *2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. *I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away *;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. *Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. *Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. *A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. *As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. *Bu the rest is history. You are a couple of years overdue. *Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. * The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was *used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. *It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS *at 12 volts worked much better. Vacuum tubes worked perfectly. *(and still do). Eisboch Can't say I miss tubes. *RF and heat burns... But good heaters.- Hide quoted text - - Show quoted text - I miss them in my guitar amp! I got them in mine... I bought a modern Fender Champ and it is a tube job. There is a second channel which adds solid state circuitry to emulate other amps, but played straight, it's a tube.. Scotty AKA Plays With Sharks:) |
Ancient circuitry
On Mon, 18 Jan 2010 11:31:21 -0500, I am Tosk wrote:
I miss them in my guitar amp! I got them in mine... I bought a modern Fender Champ and it is a tube job. There is a second channel which adds solid state circuitry to emulate other amps, but played straight, it's a tube.. Scotty AKA Plays With Sharks:) Close your eyes. Can you also hear dueling banjos. I do. |
Ancient circuitry
Eisboch wrote:
Plus, musicians being the fickle group that they are, always want modifications and tweaking. Thanks, Eisboch To say nothing of their instruments... |
Ancient circuitry
On 18/01/2010 6:38 AM, Loogypicker wrote:
On Jan 18, 8:36 am, wrote: On 17/01/2010 4:18 PM, Eisboch wrote: "Del wrote in message ... wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away ;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. Bu the rest is history. You are a couple of years overdue. Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS at 12 volts worked much better. Vacuum tubes worked perfectly. (and still do). Eisboch Can't say I miss tubes. RF and heat burns... But good heaters.- Hide quoted text - - Show quoted text - I miss them in my guitar amp! I have heard many like them for audio amps, why not make one? I wouldn't doubt you could get some pentodes, triodes, nut sized resistors, some electrolytic caps and transformers still. Wouldn't doubt you could still get the parts. And you don't need to do the slide rule thing any more as we were tough in junior high school. What a PITA. My first calc was a 9V add, subtract, multiply and divide, crappy precision but I retired the slide rule pretty quick except for logs. Funny, I think back then with 6800/Z80 uProcs being the rage and all of 4k of memory, it was more fun than today. Certainly a lot less dysfunctional politics that has crept in over the years. I took the path of microprocessors like bees to flowers. |
Ancient circuitry
"Canuck57" wrote in message ... On 18/01/2010 6:38 AM, Loogypicker wrote: On Jan 18, 8:36 am, wrote: On 17/01/2010 4:18 PM, Eisboch wrote: "Del wrote in message ... wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away ;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. Bu the rest is history. You are a couple of years overdue. Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS at 12 volts worked much better. Vacuum tubes worked perfectly. (and still do). Eisboch Can't say I miss tubes. RF and heat burns... But good heaters.- Hide quoted text - - Show quoted text - I miss them in my guitar amp! I have heard many like them for audio amps, why not make one? I wouldn't doubt you could get some pentodes, triodes, nut sized resistors, some electrolytic caps and transformers still. Wouldn't doubt you could still get the parts. Transformers, particularily output transformers, would be a little hard to come by. And you don't need to do the slide rule thing any more as we were tough in junior high school. What a PITA. My first calc was a 9V add, subtract, multiply and divide, crappy precision but I retired the slide rule pretty quick except for logs. Funny, I think back then with 6800/Z80 uProcs being the rage and all of 4k of memory, it was more fun than today. Certainly a lot less dysfunctional politics that has crept in over the years. I took the path of microprocessors like bees to flowers. |
Ancient circuitry
Del Cecchi wrote:
Transformers, particularily output transformers, would be a little hard to come by. These guys are still around... http://www.hammondmfg.com/claspg.htm -rick- |
Ancient circuitry
"Bill McKee" wrote in message m... Thanks, Eisboch Send me an Email ( bmckee at ix dot netcom dot com.) Done Eisboch |
Ancient circuitry
In article ,
says... "Canuck57" wrote in message ... On 18/01/2010 6:38 AM, Loogypicker wrote: On Jan 18, 8:36 am, wrote: On 17/01/2010 4:18 PM, Eisboch wrote: "Del wrote in message ... wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away ;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. Bu the rest is history. You are a couple of years overdue. Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS at 12 volts worked much better. Vacuum tubes worked perfectly. (and still do). Eisboch Can't say I miss tubes. RF and heat burns... But good heaters.- Hide quoted text - - Show quoted text - I miss them in my guitar amp! I have heard many like them for audio amps, why not make one? I wouldn't doubt you could get some pentodes, triodes, nut sized resistors, some electrolytic caps and transformers still. Wouldn't doubt you could still get the parts. Transformers, particularily output transformers, would be a little hard to come by. And you don't need to do the slide rule thing any more as we were tough in junior high school. What a PITA. My first calc was a 9V add, subtract, multiply and divide, crappy precision but I retired the slide rule pretty quick except for logs. Funny, I think back then with 6800/Z80 uProcs being the rage and all of 4k of memory, it was more fun than today. Certainly a lot less dysfunctional politics that has crept in over the years. I took the path of microprocessors like bees to flowers. Not to mention. There are plenty of old tube Amps available and the parts are available too... Scotty |
Ancient circuitry
"I am Tosk" wrote in message ... Not to mention. There are plenty of old tube Amps available and the parts are available too... Scotty Usually all the old tube amps need are new capacitors. Tubes, like you say are plentiful. Transformers fail rarely and are still available when they do fail. I recently came across a Paul Reed Smith solid state amp that was designed back in the late 80's. Smith retained a guy to design it, anticipating a future shortage of tubes. The amp was designed with a "harmonic generator" to emulate the sound of a tube amp. Only about 300 were built. Turns out the anticipated tube shortage never happened. Reason? During the Cold War, while the USA developed hardened solid state instruments and avionic displays, the Soviet Union stuck mostly with vacuum tube devices due to their natural immunity to radiation and EMI blasts. When the Soviet Union collapsed they had a well developed manufacturing capacity to build vacuum tubes. They took advantage of it and are now the leading producers of replacement tubes for virtually all applications. Eisboch (with more useless trivia) |
Ancient circuitry
On Jan 19, 9:00*am, "Eisboch" wrote:
"I am Tosk" wrote in ... Not to mention. There are plenty of old tube Amps available and the parts are available too... Scotty Usually all the old tube amps need are new capacitors. *Tubes, like you say are plentiful. Transformers fail rarely and are still available when they do fail. I recently came across a Paul Reed Smith solid state amp that was designed back in the late 80's. *Smith retained a guy to design it, anticipating a future shortage of tubes. *The amp was designed with a "harmonic generator" to emulate the sound of a tube amp. Only about 300 were built. * Turns out the anticipated tube shortage never happened. Reason? During the Cold War, while the USA developed hardened solid state instruments and avionic displays, the Soviet Union stuck mostly with vacuum tube devices due to their natural immunity to radiation and EMI blasts. When the Soviet Union collapsed they had a well developed manufacturing capacity to build vacuum tubes. * They took advantage of it and are now the leading producers of replacement tubes for virtually all applications. Eisboch *(with more useless trivia) Very interesting! |
Ancient circuitry
On Jan 18, 11:31*am, I am Tosk
wrote: In article c9511ebc-d7f2-449a-9d90-c55f2b828712 @m3g2000yqf.googlegroups.com, says... On Jan 18, 8:36 am, Canuck57 wrote: On 17/01/2010 4:18 PM, Eisboch wrote: "Del wrote in message ... wrote in message ... On 16/01/2010 6:17 PM, wrote: On Sat, 16 Jan 2010 14:05:54 -0800 (PST), Frogwatch wrote: Here at work, we are repairing the vacuum control circuitry for an electron microscope made in 1979. It has 6 SN7400 chips. If I remember, these are quad 2 input NAND gates. 2 of them have gone bad because the heat sinking of the board is not very good, you can see heat discoloration on the board. Back in 1974, I was 18 and was experimenting with making computer circuitry trying to make a computer cpu with a calculator chip and a buffer made from a bunch of 7400 gates as memory flip flops. I never got rid of all those old chips and still have several tubes of them unused. Now, 36 years later, I find a use for them. Never throw anything away ;-) There are still plenty of places that still stock these things. I never took the TTL plunge because I had IBM parts to play with but I have made a lot of CMOS (4xxx) stuff. Couple that with a big SSR and you can run humongous stuff straight from CMOS. (like my 11kw spa heater) Same deal, just that you are likely a few years yonger. Every TTL has a CMOS counterpart in time and CMOS was a better/newer evolution of the TTL. Used both myself but mostly TTL. Was fun to tinker with those chips on bread boards. A joy many today will never know. I always wondered if the US government got a hold of an ancient space ship and reverse engineered the electronics we have today. As we accelerated down this path about as fast as socially possible without regards to the hardware. I remember saying to people at the time that it is unlikely I will retire before we see a 4ghz computer with 4 CPUs and 4gb of ram and 4gb of hard drive as a commodity system. Only 4ghz CPU stands between me and retirement. Bu the rest is history. You are a couple of years overdue. Put in those papers. Depending on your definition of commodity of course. http://www-03.ibm.com/press/us/en/pr...ease/21580.wss I remember TTL logic being the rage in the late 70's. The problem for electrically noisy industrial applications was that a "high" was about 3.8 volts and a "low" was around 2.4 volts. A TTL logic based controller would work fine in the quiet lab, but when it was used in a real application and subjected to harsh RFI and EMI environments, there was no way of telling what it would do. It didn't take much of a electrical spike or some RFI to completely screw up the logic. CMOS at 12 volts worked much better. Vacuum tubes worked perfectly. (and still do). Eisboch Can't say I miss tubes. RF and heat burns... But good heaters.- Hide quoted text - - Show quoted text - I miss them in my guitar amp! I got them in mine... I bought a modern Fender Champ and it is a tube job. There is a second channel which adds solid state circuitry to emulate other amps, but played straight, it's a tube.. Scotty AKA Plays With Sharks:)- Hide quoted text - - Show quoted text - I'm holding out for an old vintage Vibrolux! |
Ancient circuitry
"Loogypicker" wrote in message ... I'm holding out for an old vintage Vibrolux! Too bad. Just sold one cheap. Eisboch |
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