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In article , W7TI
writes: On Wed, 22 Oct 2003 23:40:05 GMT, "Ken Finney" wrote: The semiconductor industry is one of the most bizarre there is, but it works for them. _________________________________________________ ________ Before semis became ubiquitous, tube manufacturers did about the same thing. Any idea how many variations there are on the good 'ol 6AU6? I'd guess probably between 50 and 100, some pin compatible and some not, and not one of them worked a bit better than the others. But it was a money maker for them to keep coming out with "new" tubes that everyone had to stock up on. In February, 1953, I did my first QSY on HF with a BC-339 that ran a pair of 833s in the final. 833 is not your run-of-the-mill receiver set tube. :-) About the same time a group of the guys at Army station ADA were into an argument about "how many vacuum tube types" there were then. (I guess it was something to do) Several scarfed up catalogs and things, even got the station OIC interested. I forget the exact number but it was like 3500 nomenclature types of all kinds, receiving, transmitting, power control, photoelectric eyes, whatever. By 1960 there were the 12 V filament versions of basic 6 V tubes and the other "weird" filament voltages for series-stringing to reduce the cost of a transformer in a TV set. Ruggedized versions of basic lower-power tubes for mobile and airborne were out with 5000 and 6000 series numbers. Loctals were disappearing as were the "acorn" types for VHF-UHF. Big changes everywhere, not just on TV sets, to meet both competition and new environments and frequencies. Sylvania's tube spec book had small loose-leaf pages, at least two update sets per year...:-) By 1980 the number of available-on-the-market semiconductors were at least two orders of magnitude greater than that old 1953 group compilation of tubes done at ADA...maybe three orders of magnitude. All kinds of ICs for many, many purposes and universal applications like the all-purpose Opamp (bless you, Bob Widlar, wherever you are). By 1990 there was already a trend of "downsizing" semiconductor product lines. National Semi and Motorola data books were no longer expanding beyond their one-foot shelf width for most volumes. There was COMPETITION on the world market for all kinds of electronics and it was fierce and hot, not just in PCs+peripherals but all kinds of electronic things and products. The number of available semi products had expanded beyond reasonable capitalistic bounds and the market overall just couldn't sustain all of them. Ahhhhh, the good old days. Bill, I respectfully give you a pthbtbtbt on that. :-) I DON'T want them back now that the whole electronics world is swimming in a sea of wonderful parts plethora! Sure, it's getting to be a chore on selecting a precise IC or transistor...because there's SO MANY to choose from. In 1956 one was lucky to get a transistor (affordable) that would work beyond audio frequencies. Just got a Mouser paper catalog a couple days ago. It's a full inch and a half thick with very thin paper contents. The Digi-Key industrial catalog on paper is about that size, maybe larger. HUGE inventories! Pages of semiconductor components that don't seem to stop. All kinds of semis, all kinds of other components...TTL expanded to many families, CMOS functional work-alikes to TTL numbers for zilch power drain...voltage regulators, band-gap voltage references more precise than zeners, all kinds of FETs capable of POWER handling, RF transistors capable of working at 1.2 GHz, small signal FETs approaching that. Huge selection of Microchip microcontrollers that anyone can use and program with free software, displays that knock the eyes out, LEDs of many colors. Yes, the traditional "radio" parts aren't there anymore, not in the Allied or Newark catalogs either. "Plate transformers" are hard to get and only specialty places still sell variable capacitors for "tuning." Even vacuum tube sockets are getting hard to get. The electronics world get very big everywhere and it got much lower in voltage and much bigger in functions for all kinds of purposes. Times change. These are times of paradise for designers! I wouldn't have it any other way... :-) Len Anderson retired (from regular hours) electronic engineer person |
In article , W7TI
writes: On Wed, 22 Oct 2003 23:40:05 GMT, "Ken Finney" wrote: The semiconductor industry is one of the most bizarre there is, but it works for them. _________________________________________________ ________ Before semis became ubiquitous, tube manufacturers did about the same thing. Any idea how many variations there are on the good 'ol 6AU6? I'd guess probably between 50 and 100, some pin compatible and some not, and not one of them worked a bit better than the others. But it was a money maker for them to keep coming out with "new" tubes that everyone had to stock up on. In February, 1953, I did my first QSY on HF with a BC-339 that ran a pair of 833s in the final. 833 is not your run-of-the-mill receiver set tube. :-) About the same time a group of the guys at Army station ADA were into an argument about "how many vacuum tube types" there were then. (I guess it was something to do) Several scarfed up catalogs and things, even got the station OIC interested. I forget the exact number but it was like 3500 nomenclature types of all kinds, receiving, transmitting, power control, photoelectric eyes, whatever. By 1960 there were the 12 V filament versions of basic 6 V tubes and the other "weird" filament voltages for series-stringing to reduce the cost of a transformer in a TV set. Ruggedized versions of basic lower-power tubes for mobile and airborne were out with 5000 and 6000 series numbers. Loctals were disappearing as were the "acorn" types for VHF-UHF. Big changes everywhere, not just on TV sets, to meet both competition and new environments and frequencies. Sylvania's tube spec book had small loose-leaf pages, at least two update sets per year...:-) By 1980 the number of available-on-the-market semiconductors were at least two orders of magnitude greater than that old 1953 group compilation of tubes done at ADA...maybe three orders of magnitude. All kinds of ICs for many, many purposes and universal applications like the all-purpose Opamp (bless you, Bob Widlar, wherever you are). By 1990 there was already a trend of "downsizing" semiconductor product lines. National Semi and Motorola data books were no longer expanding beyond their one-foot shelf width for most volumes. There was COMPETITION on the world market for all kinds of electronics and it was fierce and hot, not just in PCs+peripherals but all kinds of electronic things and products. The number of available semi products had expanded beyond reasonable capitalistic bounds and the market overall just couldn't sustain all of them. Ahhhhh, the good old days. Bill, I respectfully give you a pthbtbtbt on that. :-) I DON'T want them back now that the whole electronics world is swimming in a sea of wonderful parts plethora! Sure, it's getting to be a chore on selecting a precise IC or transistor...because there's SO MANY to choose from. In 1956 one was lucky to get a transistor (affordable) that would work beyond audio frequencies. Just got a Mouser paper catalog a couple days ago. It's a full inch and a half thick with very thin paper contents. The Digi-Key industrial catalog on paper is about that size, maybe larger. HUGE inventories! Pages of semiconductor components that don't seem to stop. All kinds of semis, all kinds of other components...TTL expanded to many families, CMOS functional work-alikes to TTL numbers for zilch power drain...voltage regulators, band-gap voltage references more precise than zeners, all kinds of FETs capable of POWER handling, RF transistors capable of working at 1.2 GHz, small signal FETs approaching that. Huge selection of Microchip microcontrollers that anyone can use and program with free software, displays that knock the eyes out, LEDs of many colors. Yes, the traditional "radio" parts aren't there anymore, not in the Allied or Newark catalogs either. "Plate transformers" are hard to get and only specialty places still sell variable capacitors for "tuning." Even vacuum tube sockets are getting hard to get. The electronics world get very big everywhere and it got much lower in voltage and much bigger in functions for all kinds of purposes. Times change. These are times of paradise for designers! I wouldn't have it any other way... :-) Len Anderson retired (from regular hours) electronic engineer person |
Avery Fineman wrote:
By 1960 there were the 12 V filament versions of basic 6 V tubes and the other "weird" filament voltages for series-stringing to reduce the cost of a transformer in a TV set. Hmm... and to think it wasn't until the '80s or thereabouts that cars started to become noticeably non-user-serviceable... (Well, I suppose you guys just checked the pins of the tube bases to see where the voltage stopped? Not too bad...) One of the things people should keep in mind is that -- especially in the digital world -- one device can replaces tons of older ones. If you need fast digital logic, use a CPLD or FPGA. For slower stuff, nothing can beat the versatility of a microcontroller, and these days they're dirt cheap with tons of features. Analog electronics is certainly still struggling in that programmable analog devices based on, e.g., switched capacitor architectures tend to noticeably limit performance in a manner that makes their usage nichey (i.e., if you can afford the ADC and DAC anyway, a lot of programmable analog chips perform no better than an ADC, DSP, and a DAC), but at the same time Analog Devices, Linear Tech., etc. keep cranking out some very impressive op-amps, regulators, etc. (Just off-hand, the LTC1799 is a pretty nice chip that's already found its way into some amateur radio equipment!) I'm personally quite interested in bridging the digital and analog worlds of radio design, applying each where it makes the most sense. ---Joel Kolstad |
Avery Fineman wrote:
By 1960 there were the 12 V filament versions of basic 6 V tubes and the other "weird" filament voltages for series-stringing to reduce the cost of a transformer in a TV set. Hmm... and to think it wasn't until the '80s or thereabouts that cars started to become noticeably non-user-serviceable... (Well, I suppose you guys just checked the pins of the tube bases to see where the voltage stopped? Not too bad...) One of the things people should keep in mind is that -- especially in the digital world -- one device can replaces tons of older ones. If you need fast digital logic, use a CPLD or FPGA. For slower stuff, nothing can beat the versatility of a microcontroller, and these days they're dirt cheap with tons of features. Analog electronics is certainly still struggling in that programmable analog devices based on, e.g., switched capacitor architectures tend to noticeably limit performance in a manner that makes their usage nichey (i.e., if you can afford the ADC and DAC anyway, a lot of programmable analog chips perform no better than an ADC, DSP, and a DAC), but at the same time Analog Devices, Linear Tech., etc. keep cranking out some very impressive op-amps, regulators, etc. (Just off-hand, the LTC1799 is a pretty nice chip that's already found its way into some amateur radio equipment!) I'm personally quite interested in bridging the digital and analog worlds of radio design, applying each where it makes the most sense. ---Joel Kolstad |
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