John Curl's Blowtorch preamplifier part II

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It is just that here machinist still think in thousandth's of an inch and they still use these types of measurement tools. I could go buy all new micrometers but why would I? As for liquid measure I buy fuel by the gallon, but I do use milliliters and liters and am used to that. I grew up in a medical lab and you always use metric units there so that is some of the reason I find it so easy to go back and forth. We called it CC's before all along and it is second nature. I convert things in my head all the time with linear measure, you only need to remember 25.4 =1 to do that.
 
It is just that here machinist still think in thousandth's of an inch and they still use these types of measurement tools. I could go buy all new micrometers but why would I? As for liquid measure I buy fuel by the gallon, but I do use milliliters and liters and am used to that. I grew up in a medical lab and you always use metric units there so that is some of the reason I find it so easy to go back and forth. We called it CC's before all along and it is second nature. I convert things in my head all the time with linear measure, you only need to remember 25.4 =1 to do that.

i'm not saying you personally are crazy for using them, more the country as a whole :tongue: I totally get your situation as its what you are used to and as you mention, its what you are tooled up for and I imagine it would be an expensive exercise to replace some of your machining tools.

the fact you have inconsistencies industry to industry and have to switch back and forth, that would annoy me. I dont really have difficulty with the conversions, I would just find it annoying. as I said I use feet and occasionally inches quite a bit for rough estimates, but I would never use it for something precise, some things just dont work out neatly and you would end up having to mix decimal fractions and imperial or use 2 or 3 different measures to make up the total. like with 1000th of an inch, if you had 250/1000ths, would you say 1/4" or .250" ?

I find it interesting, not taking the ****, especially with someone with your background in high precision engineering and computing.
 
qusp,
You are correct we would say ,250 and everyone would instantly know what we are talking about and that would infer the tolerance at the same time. If you say 1/4 inch then it would be inferred as a rough number that way. So I guess it is just the language that we use here, it is rather precise in how we use it. We do measure to .0001" when we are being more precise and then you are using finer precision measurement devices. But if you don't need to you wouldn't do that as the precision to do that is a pain in the rear. Funny thing is we also use micron to describe thickness of film! We are rather messy in that regards. We mix imperial and metric all the time and we are just used to it. Even the pot smokers buy their stuff by the gram, but then switch to the ounce. Got to love it!
 
@ Kindhornman:
yeah, but what would you do for precision if you couldnt steal some decimal? 0.0001" is not strictly imperial really is it?, its more imperial units, with decimal fractions for accuracy. if its like that sure I guess its neither here nor there as its just a unit with decimal fractions, no different to a m with decimal fractions in the end, its more the large or small numbers where it gets messy, or where you have to mix several different units that are each divided into different numbers instead of having a base. by the sounds of it you just switch to a mutant 'impecimal' system when thats necessary. ;)

Even the pot smokers buy their stuff by the gram, but then switch to the ounce.
same here, then it would go to lb, then back to kg (I believe it works this way with other drugs too, or so i've been told ;) ). Back in the day, I used to buy what were termed '8 balls' which is an eighth of an ounce. A legacy you guys, popular culture and hollywood have left us I suspect. of course we used to use imperial here too, but not in my lifetime
 
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the reason its kinda on my mind is the annoyance of having to do PCB layouts that combine the 2, so you will be in the position of doing a layout with metric trace widths, or mils, with some parts with metric pin spacing and some parts with imperial (or rather impecimal) then specify copper foil by the ounce, vias with mils

aaaarrrrgh…. it messes with my chi, luckily i'm doing a lot of stuff with planes and fills, so its not so annoying. but its messy because you cant just pick a grid and have it suit everything on the board.
 
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qusp,
With the current model of globalization it does seem that we are moving more and more to the metric system. I agree that it is easier to use with a base ten for everything, but some things just die slowly. Why things are still so intermixed with things like the Troy weights for things like the copper amounts don't ask me. Then again why do the English still have Kings and Queens when they really don't make any sense anymore? Tradition is hard to kill, people are just attached to some old things and that is why we still have imperial measure today. In science we have moved away from it but in other aspects we just hold on to it, perhaps just to mess with the rest of the world, sort of like the French still being peeved that English is the international language. At least we are smart enough to be able to understand them both! Some can't seem to get either one right.......
 
but there seems to be a meaning relating to typically 100-1000nm scale (or microscopic and macroscopic), which certainly falls within the boundaries of modern device structures. but I havent read your link. mesoscopic physics would seem to have context in fabrication of solid state electronics surely?

Mesoscopic physics - Wikipedia, the free encyclopedia

sorry for the wikipedia reference :redface:

not taking sides here, it does seem that the word itself is not out of place, I have no comment on the content of the paper, or how John referenced the word
 
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Scott,
I haven't read the entire paper yet, I did copy it to my documents to read, but the math is over my head. I do understand what the subject is about but not sure how on the scale of audio circuits it would be applicable? Only in the sense of some hidden noise factor is all I could conjecture, but I'll leave that to someone of your knowledge to decide if it is relevant in the least. No reason to look any further than this while still trying to understand the normal noise contributors.
 
Scott,
I haven't read the entire paper yet, I did copy it to my documents to read, but the math is over my head. I do understand what the subject is about but not sure how on the scale of audio circuits it would be applicable? Only in the sense of some hidden noise factor is all I could conjecture, but I'll leave that to someone of your knowledge to decide if it is relevant in the least. No reason to look any further than this while still trying to understand the normal noise contributors.

I have never found any noise mechanism that was not explainable by macro scopic physics. But we are not talking just about noise the claims involve precognition and question causality.
 
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Not exactly, look up the standard meaning of mesoscopic, I thought it might be clear to any reasonable person how inapplicable this was to audio. Seriously, folks you don't feel your intelligence is being insulted?

The standard meaning of mesoscopic leaves a lot of holes for the imagination to escape through
Mesoscopic physics - Wikipedia, the free encyclopedia (no red face gusp)
I found some hard limitations in part 1.1 The Mesoscopic Regime in this informative link http://www-ipcms.u-strasbg.fr/IMG/pdf/petra.pdf
The rest of the paper explains the why and how of these limitations (not many buzz words)

(for your information, I am not insulted, as I belong to the group "with the need for basic electronic circuit design skills") :)

George
 
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