I did work on a Marantz -- installing IC sockets. That was what made me ask the question of how thin it is typically. I'll do some tests and report what affect thin copper has vs 1-2 oz copper.
[BTW - I dont build audio circuits with smd parts.... dont see any reason to do so. Offers me no sonic advantage and a lot of head-aches.]
THx-RNMarsh
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A stirling effort by Dimitri then
, and thanks to you both for putting such information in usefully available form.I would not expect a novice engineer without proper exposure to real world professional audio to make head or tails of much of what you discuss in the pdf.
For the record, my father is similar age to you John (only recently retired), and has been written up as the icon of the Australian radio broadcast industry....we play in his garage and I get to hear many stories of how things were done.
The SSM2142 audio balanced line driver was drunkenly conceived on a paper napkin in a Dallas bar....my father explained what was needed and how to do it....three weeks later Derek Bower sent my father initial examples.
That product went on to become highly popular in the professional audio world.
Sometimes it is the new dog teaching the old dog (concepts parallel to BQP and other stuff), but not always....we have beery intelligent relaxed technical discussions, and I get plenty of interesting technical tips as I have gotten from you.
He has threatened to write a book of industry memoirs....with Dimitri's effort you are half way there.....I am sure you could put something together, all you need is a Dictaphone.
Dan.
BTW, I took your 'don't blame me' quip as humorous tongue in cheek.....it's a sad pity that at least one member elected not to see it that way.
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You are very tiring. Do you think this thing was invented by someone who never hunted, never thought about how to kill a prey, never speculated 'if I only could do it from farther away'? Basic R&D my friend.
jan
I Should Have Patented This....
Vacuum desoldering irons are recipe for damaging modern (and old) consumer boards.
I use a spring desolder pump....the trick is to shorten the teflon tip by 3mm or so, and then fit a 10mm or so length of 1/4'' silicone tubing over the teflon so that it protrudes by 3mm or so.
This gives a heatproof resilient compliant tip that prevents the recoil from shifting the copper traces/pads, and provides perfect seal sucking all solder away from the joint.
Apply liberal new solder and flux beforehand.
The silicone tubing end will last a couple of thousand joints...just trim it back 3mm or so and you are good for another couple of thousand desolders.
Lube the internals of the solder sucker with Mr Sheen or Marveer wax polish....prevents solder particles sticking internally.
I have reworked hundreds of thousands (millions ?) of joints this way and have never lifted/shifted a track/pad since adopting this method.
Aeromodel shops sell it as fuel tubing.
Dan.
Vacuum desoldering irons are recipe for damaging modern (and old) consumer boards.
I use a spring desolder pump....the trick is to shorten the teflon tip by 3mm or so, and then fit a 10mm or so length of 1/4'' silicone tubing over the teflon so that it protrudes by 3mm or so.
This gives a heatproof resilient compliant tip that prevents the recoil from shifting the copper traces/pads, and provides perfect seal sucking all solder away from the joint.
Apply liberal new solder and flux beforehand.
The silicone tubing end will last a couple of thousand joints...just trim it back 3mm or so and you are good for another couple of thousand desolders.
Lube the internals of the solder sucker with Mr Sheen or Marveer wax polish....prevents solder particles sticking internally.
I have reworked hundreds of thousands (millions ?) of joints this way and have never lifted/shifted a track/pad since adopting this method.
Aeromodel shops sell it as fuel tubing.
Dan.
There was undoubtedly an evolutionary process in its development, and the final form(s) was/were the result of endless variation, trial-and-error, and ruthless selection (the "error" part often did not end well) over generations. Thus was all early development.
In the past century or two, with a basic understanding of how the material world works used as a starting point, the climb up the technological curve has been orders of magnitude steeper- and I think you understand why.
We all stand on the backs of those that came before us. Whatever field we work in to disregard what has come before whether good or bad would be rather silly. In this realm we are happy to look back at things that John and many others have created and use those basic designs to move forward and create something new where it is desired. Without those who came before you have to start with nothing, a very difficult place to be for sure.
I imagine that the precursor to the boomerang was a rock or a stick. I'm going to eat and I want to kill that animal, I can throw a rock from over here and if I miss I can run! Then perhaps a big stick and on from there. An evolution of design from a basic necessity of wanting to survive by eating! So many starts to things were just simple observation but from there you have to have a basic understanding of how something actually works to understand and move forward.
SY's example like the discovery of polycarbonate plastic are found through serendipity but at the same time the person who discovered polycarbonate did have a basic intent to do something, it just wasn't what was originally the desired result. A mistake was recognized as something useful and then the real work begins.
I imagine that the precursor to the boomerang was a rock or a stick. I'm going to eat and I want to kill that animal, I can throw a rock from over here and if I miss I can run! Then perhaps a big stick and on from there. An evolution of design from a basic necessity of wanting to survive by eating! So many starts to things were just simple observation but from there you have to have a basic understanding of how something actually works to understand and move forward.
SY's example like the discovery of polycarbonate plastic are found through serendipity but at the same time the person who discovered polycarbonate did have a basic intent to do something, it just wasn't what was originally the desired result. A mistake was recognized as something useful and then the real work begins.
Yes, by directed research (in the sense of chemistry rather than alchemy or "hey, let's throw a bunch of **** together and see what happens!") and a prepared mind (a well-trained chemist).
It was not a garage discovery by simple-minded ditch digger.
Actually I don't believe you need to have a detailed understanding how something works to be able to recognise it's utility and use it, even refine it. I doubt that those hunters knew about gravity and aerodynamics and kinetic energy in any significant way.
An example: you must have seen outfielders (right name?) catch a ball; do they do any advanced calculus to calculate where it will land, and then move to that position?
No - the ONLY trick is to make sure that the angle under which you see the ball does not change. If you do that, the ball ends up in your hand. Very easy.
Do they know this? Most did not - they just did it!
Jan
An example: you must have seen outfielders (right name?) catch a ball; do they do any advanced calculus to calculate where it will land, and then move to that position?
No - the ONLY trick is to make sure that the angle under which you see the ball does not change. If you do that, the ball ends up in your hand. Very easy.
Do they know this? Most did not - they just did it!
Jan
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Frankly, no idea, Richard. Remember, I live in Serbia.
I have a man doing the PCB for me, and he does all the purchasing. Currently, the best he has is 50 microns, I'm not very happy with that, I'd prefer 7 microns, but right now, it seems I don't have a choice.
I would suggest you fing a PCB printing/drilling service near you, go there and ask them for samples, they always have leftovers, cutouts, etc, if you just want to satisfy your curiosity. Or they can cut more serious pieces for you usually on the spot, depending on what you want.
Jan, with all respect, I think you are looking at it far too technically. While in technology you are probably quite right, do remember that Alexander Fleming did discover panicillin quite by accident, he simply forgot to put a plate back in the fridge, and it turned kinda green by the morning he was back in the lab.
Do you really think one of our ancestors thought out a scientific test to create wine from grape juice? Or vinegar from wine? Or create penicillin crossed hard cheese you Dutch are such masters of (I wouldn't be caught dead without some Old Amsterdam cheese in my fridge!)?
Discovering new Saturn moons is another matter, that is, as you say, hard science and no accident.
If you leave a plate out and it turns green do you leap to the conclusion that you have discovered a new medicine?
Edit: the point is not that accidental discoveries are not made. The point is that such an accidental or serendipity only happens to those that know the field, know the details and recognise the lucky shot for what it is. SY's example is a good one: the guy who made the 'accident' happen had no clue - it was the experts in the field that recognised it for what it was.
Jan
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