What has pleased you today

A place for some light-hearted chat.
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RobertArthur
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Re: What has pleased you today

Post by RobertArthur »

@ AJM, if you were to go deep down in a chip, a processor or memory cells, you would finally arrive at a level where you can find what I have called "transistor functions". Incredible small compared with what you still could see under a standard microscope in early analogue operational amplifies as the 741 and 709. Then the digital domain: from the first discrete digital logic building blocks to integrated circuits, RTL, TTL, CMOS technology. A race between chip designers and the guys specialised in photolithography. How to get millions or billions of tiny transistors etched on to a silicon wafer for a processor. The transistor, although being invisible, is still alive. I'm not referring to the loads of BC 107s, BC 109s, 2N3055s hiding in drawers here, also alive, but invisible for those bringing in gear - Quad amplifiers - to be repaired. Not of any use for computers I noticed.....
Last edited by RobertArthur on Fri Dec 25, 2020 10:00 pm, edited 1 time in total.

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JohnnyD
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Re: What has pleased you today

Post by JohnnyD »

You left out BC 108, was that the one in a metal case? I remember building things with BC 107 and 109's, and 1N4001 diodes in a rectifier circuit.....god that makes me feel old

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RobertArthur
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Re: What has pleased you today

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JohnnyD, if you want to register a complaint about the missing BC108 the only thing I can say in my defense is that I ran out of stock, the BC 108 ceased to be available, went to see other electronic equipment. So not being able to confirm if the package is metal or plastic I preferred to remain silent. Here comes the judge, show exhibit # 1:

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Re: What has pleased you today

Post by JohnnyD »

I remember trying to build a tv tennis game back in the 1980's from Elektor magazine, full of 74121 monostable multivibrators, I had no idea what they were and I still dont :lol:

I think the BC108B was used in the TV output mudulator for Ch36 and the 1N4001 were used in the rectifying circuit for the power supply for it all, I seem to recall the 4001 meant 1A as they also did 4002, 3 and 4, but it was so long ago .......

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Re: What has pleased you today

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RobertArthur wrote:
Fri Dec 25, 2020 10:17 pm
JohnnyD, if you want to register a complaint about the missing BC108 the only thing I can say in my defense is that I ran out of stock, the BC 108 ceased to be available, went to see other electronic equipment. So not being able to confirm if the package is metal or plastic I preferred to remain silent. Here comes the judge, show exhibit # 1:

Image
You can restock :lol:

https://uk.farnell.com/multicomp/bc108b ... dp/9206744

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RobertArthur
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Re: What has pleased you today

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JohnnyD, the BC 108 was also popular in pre-amplifiers, being low noise and having a nice hFE linearity. In the Huntingdon designs of Peter Walker you'll see several BC 109s in the pre-amp modules of the Quad 33. I still like the qualities of the 33/303 combination, but... Doug Self published one day, in Wireless World, a discrete dc coupled design, more an op-amp than the classical approach and higher dc voltages to feed this new audio animal (Quad 33 only 12 V). To my surprise it performed, after modifications and letters across the Channel, much better: more head room in the disc stage. I discovered lots of new sounds playing vinyl (Thorens): what was a sort of blurred, undefined low frequency rumble appeared to be a mouth harp, crystal clear, the intro of a song on a record of the Lovin' Spoonful. And I thought: perhaps these guys of the Golden Ear Brigade do have a point. There is more than only advanced verifiable measuring techniques.

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Re: What has pleased you today

Post by rabbit »

RobertArthur wrote:
Fri Dec 25, 2020 9:56 pm
@ AJM, if you were to go deep down in a chip, a processor or memory cells, you would finally arrive at a level where you can find what I have called "transistor functions". Incredible small compared with what you still could see under a standard microscope in early analogue operational amplifies as the 741 and 709. Then the digital domain: from the first discrete digital logic building blocks to integrated circuits, RTL, TTL, CMOS technology. A race between chip designers and the guys specialised in photolithography. How to get millions or billions of tiny transistors etched on to a silicon wafer for a processor. The transistor, although being invisible, is still alive. I'm not referring to the loads of BC 107s, BC 109s, 2N3055s hiding in drawers here, also alive, but invisible for those bringing in gear - Quad amplifiers - to be repaired. Not of any use for computers I noticed.....
Yes but they are not transistors they are gates. AJM was right

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Re: What has pleased you today

Post by RobertArthur »

@ Rabbit, so transistors are Fred Flintstone stuff and gates something completely different, not any hardware evolution or timeline between them? I must hurry to the dechetterie, no, not open today, to throw away more than one textbook.

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Re: What has pleased you today

Post by FrenchForumSurvivor »

rabbit wrote:
Sat Dec 26, 2020 9:44 am
RobertArthur wrote:
Fri Dec 25, 2020 9:56 pm
@ AJM, if you were to go deep down in a chip, a processor or memory cells, you would finally arrive at a level where you can find what I have called "transistor functions". Incredible small compared with what you still could see under a standard microscope in early analogue operational amplifies as the 741 and 709. Then the digital domain: from the first discrete digital logic building blocks to integrated circuits, RTL, TTL, CMOS technology. A race between chip designers and the guys specialised in photolithography. How to get millions or billions of tiny transistors etched on to a silicon wafer for a processor. The transistor, although being invisible, is still alive. I'm not referring to the loads of BC 107s, BC 109s, 2N3055s hiding in drawers here, also alive, but invisible for those bringing in gear - Quad amplifiers - to be repaired. Not of any use for computers I noticed.....
Yes but they are not transistors they are gates. AJM was right
Rabbit, and your expertise in the world of computing and electronics is what, precisely?
"I am a man of fixed and unbending principles, the first of which is to be flexible at all times." - Everett Dirksen

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Re: What has pleased you today

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ajm wrote:
Fri Dec 25, 2020 8:59 pm
"Transistors"? They disappeared years ago.
I've always had a bit of a problem with timing. I had a keen interest in radio and electronics from a young age. In school I was lucky enough to have access to a course in the subject. Learned the ins and outs of electronic theory and applications using vacuum tubes (valves to you lot) and basic circuitry. Loved it. The next opportunity to engage in the subject was two years later when tubes were old hat and transistors were the thing. I never got caught up with the technology (or the maths) so my dream of electronic engineering went south and after school I ended up as a prototype wireman for a while. Same these days with computers. I have built a few from scratch but couldn't code for a light switch. :?
I have a problem with smartphones. I need one hand to hold the phone, another to peck/push/and swipe, and another to hold the magnifying glass.

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