I am sorry but did you mean ad (advertisement) or add as in extra ?. ACPD for "jobs" rather than ACD . Disorders are still disorders .
Scott
You have spend a good part of your life designing ICs. You know very well what you are talking about when small dimentions and what matters there is brought into discussion.
This is understood and respected by everyone here.
IMO any nonsense flying around, better be considered as a reflexion of rare spontaneous psychological self adjusting activities granded to our quere human nature and not treated as a technical issue.
George
Well I treat this nonsense to be dismissed, why waste your time on it? Frankly I'm tired of it.
Bragging ...
although a gear enthusiast,
and boat anchor aficionado,
yet,
i felt the need to limit the purchase of certain tools.
throughout the 80's, i had no calculator.
however,
i had figured out how to hack the telephone,
to accomplish whatever computational needs arose.
`````````````````````````````````````````````````````
would this be subliminal advertising for things made of apricot(s)?
although a gear enthusiast,
and boat anchor aficionado,
yet,
i felt the need to limit the purchase of certain tools.
throughout the 80's, i had no calculator.
however,
i had figured out how to hack the telephone,
to accomplish whatever computational needs arose.
`````````````````````````````````````````````````````
would this be subliminal advertising for things made of apricot(s)?
Gee, really? Who is your biggest trading partner? Hint: there is no ocean between us. Trade volume between Canada and the USA eclipses trade volume between the USA and any other country, it's not even close. We converted to the metric system in the 1970's. But you figure "globalization" is the driving force to convert? Seriously? Your biggest supplier and customer doesn't matter, just "globalization"! I really wish you guys would stop pretending that you invented the British Imperial System (was 1776 for nothing?) and get with the program. When the biggest economy in the world thumbs its nose at its closest trading partners it costs us all money.
That said, we have some odd combinations of units. When I buy meat, the price is displayed in $/lb and as $/Kg, but either way I know I want a pound of ground beef or a Kg of chicken, and I do a quick-and-dirty conversion. Most of us born in say 1955 or later can do the rough conversion in our heads. Temperature is always degC, except oven temperatures which are degF. For weather I no longer have an internal "Fahrenheit" scale, I need to convert from "real degrees" to communicate with Americans. When I talk about distances I generally use metric, except for my own height (6'1", and I would need to think for a minute to convert that to cm), and when I buy a stick of lumber I ask for a 2x4 (even though its dimensions are probably specified in mm, not inches). Fuel mileage is liters/100Km, which is much more sensible than mpg (esp since the "g" is location-dependent). And we use g/Kg to discuss weight, except for the weight of a person, which is always expressed in lb.
I recall an article I read years ago about precision vs accuracy in computer numeric representations, which asked one to calculate the velocity of light in furlongs per fortnight. The point was to show where one might lose precision in calculations (given a number of bits in which to represent intermediate results).
Gents
nice excursions about calculators etc. Let's come back to preamps... what's your opinions on preamps gain and power amplifiers sensitivity (and of course headroom)?
As I stated some donkey's years in this thread the perfect pre would be an attenuator with unbity gain - and the pre's gain moved into the phono stage and / or line stage. For example we have an signal output from the phono with 1Vrms and a sensitivity of the line with 0.5Vrms - and 6dB headroom.
Another statement out in the field is that the preamp is responsible for the sound. So we can reduce the phono's gain and sensitivity of the power amp, the gain of the line stage is, for example, 20dB.
Pros and cons?!
nice excursions about calculators etc. Let's come back to preamps... what's your opinions on preamps gain and power amplifiers sensitivity (and of course headroom)?
As I stated some donkey's years in this thread the perfect pre would be an attenuator with unbity gain - and the pre's gain moved into the phono stage and / or line stage. For example we have an signal output from the phono with 1Vrms and a sensitivity of the line with 0.5Vrms - and 6dB headroom.
Another statement out in the field is that the preamp is responsible for the sound. So we can reduce the phono's gain and sensitivity of the power amp, the gain of the line stage is, for example, 20dB.
Pros and cons?!
Regarding PCB design, if you use modern SMD devices they are all metric, I use metric exclusively and have done for years, it makes interfacing with the mechanical sides of things easier as well...All modern new SMD devices are hard metric.
http://www.dnu.no/arkiv1/The CAD Library of the Future.pdf
A bit of reading, also the MOST up to date and widely used standard for PCB footprints is the IPC-7351B, probably all big companies use it as a basis for there component footprints. I only use thou (or mils) when I'm feeling really retro these days.
http://www.dnu.no/arkiv1/The CAD Library of the Future.pdf
A bit of reading, also the MOST up to date and widely used standard for PCB footprints is the IPC-7351B, probably all big companies use it as a basis for there component footprints. I only use thou (or mils) when I'm feeling really retro these days.
How do you know? Who measured it, what did they use?
We use lots of Faro arms, and lots of laser trackers with fiducials built right into the components. Even with 8 laser trackers taking multiple reads, we can't measure to that accuracy. Yes, readings will be at the tenth micron level, but repeatability just isn't there. We take multiple readings and look at the distribution.
In working with a watchmakers lathe, the 8mm collets can be very accurate, but that's more sideplay than anything else...good runout specs.
Perhaps your specification is actually a surface finish specification, as I suspect that to be the important measure.
All this talk of digital vernier calipers.. The watchmaker's lathe I have has a cross-slide in metric. When I measure movement using the digital, the measured error is exactly 10 microns per mm. 10mm move...100 micron error. Given the vernier was 30 dollars out of home depot, I'm confident it's the caliper that has the gain error.
I found the discussion of the normal to superconductor interface interesting. Specifically, the reflection of the electron at the interface, with a "hole" travelling backwards in the normal material and the implication that this mechanism generates the cooper pair.
I've never heard the experts mention this in the meetings, I'll have to ask about it when I get a chance..(but in private of course...better silent and thought a fool...)
jn
Have agree with you since the 7th grade (about 1968) could not understand why we did not go metric . Easier to teach (decimal system ) strangly some of it has converted in car industry 5 liters v8's( should be 305 cubic inch but they call a 302 as such) and most of the bolts have gone metric . 8mm is easier than 5/16 to deal with . So how many furlong in a fortnight does light travel ?
yes, but audio does not yet use all modern devices, even SMD and I work almost exclusively in SMD. the majority of the parts are metric thank god, but there is always some bastard of an SOIC, QSOP, MSOP to come screw that up. luckily 0.01mm will resolve that, but its still annoying.
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Reference pins and hole templates, with minimum pin/hole clearance.
(getting a constant temperature is more tiresome)
1 micron surface finish flat/round is child's play, and boring. Spent half a childhood watching and waiting for the spindle to rotate to the other side of the product, parts for punch/press/injection molds.
(more exciting is ripping the skin of a right thumb all off at a heavy 3-phase column drill, or punching off the side of a middle finger under a 50 ton press. fortunately, I'm vegetable top and bottom
)
nezbleu,
I understand that you are our trading partner but at the same time besides lumber I can't think of a product that I buy that comes from Canada? Seriously it is hard to find almost anything these days that doesn't say made in China in most places. I do work with the Chinese and do convert everything to metric before I even consider sending something to them, I can just imagine what would happen if I didn't do that!
JNeutron,
I'm with you on the laser tracker and the Farro arms, I ran a tool shop for an aerospace company and I can confirm that accuracy is not what people think it is. I had to get a Boeing rep we had in-house to back me up when they tried to change some test protocols from Theodolite to laser tracker that were over 30 years old, they would have all failed if we did that and the entire Apache rotor blade program would have come to a dead stop. I laughed and so did my tool and die makers when some of the tolerances were called out, we did not have temp controlled rooms where we were working, how are you supposed to hold some of those tolerances when the ambient temp would change from day to day and hour to hour?
Triodethom,
Try and figure out a set of Wentworth wrenches and give me a call! That had to be the most confusing thing I've ever seen. I gave those to a guy who restored old Bentley and RR cars as I had no use for them. Do you really want them to call it out as a 4.998 liter engine or something like that, or isn't 5 liters close enough? I have three crankshafts for old Z'28 302 engines and I will call them that or a 5 liter and people will know what I am saying.
I understand that you are our trading partner but at the same time besides lumber I can't think of a product that I buy that comes from Canada? Seriously it is hard to find almost anything these days that doesn't say made in China in most places. I do work with the Chinese and do convert everything to metric before I even consider sending something to them, I can just imagine what would happen if I didn't do that!
JNeutron,
I'm with you on the laser tracker and the Farro arms, I ran a tool shop for an aerospace company and I can confirm that accuracy is not what people think it is. I had to get a Boeing rep we had in-house to back me up when they tried to change some test protocols from Theodolite to laser tracker that were over 30 years old, they would have all failed if we did that and the entire Apache rotor blade program would have come to a dead stop. I laughed and so did my tool and die makers when some of the tolerances were called out, we did not have temp controlled rooms where we were working, how are you supposed to hold some of those tolerances when the ambient temp would change from day to day and hour to hour?
Triodethom,
Try and figure out a set of Wentworth wrenches and give me a call! That had to be the most confusing thing I've ever seen. I gave those to a guy who restored old Bentley and RR cars as I had no use for them. Do you really want them to call it out as a 4.998 liter engine or something like that, or isn't 5 liters close enough? I have three crankshafts for old Z'28 302 engines and I will call them that or a 5 liter and people will know what I am saying.
Mr John,
you might like my computer desk, btw.
$20k prototype of a table for medical surroundings, can lift 4400lb from 2' to 6' height, by hand or electrically, the 6' part of telescopic feet makes it difficult)
(5-head MD goes corporate enterprise club offered three times the normal manufacture cost, for them to be able to also charge three times as much leverage. so my old man told them to go screw themselves, literally. For a 2000 table contract at $2k each, in the late '70s, I'd likely been much more cooperative.
) Sentimental memorabilia with a 32'' x 60' Ikea solid beach top.
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