Current RFIP solutions are based on silicon chips - which are dirt cheap! The silicon is so inexpensive, that the cost of the chips is insignificant compared to the rest of the device. The expensive parts are the off chip componants: the packaging, the antenna, etc.
The big advantage of the other techniques is that they are well suited to making large devices cheaply - like the antenna.
As other have mentioned, this is wrong. Silver is the best conductor, followed by copper, then gold. (see http://hypertextbook.com/physics/electricity/resis tance/ for more details)
What gold does do best is resist corrosion, which is why it is often used for connectors. Silver and copper both oxidize very rapidly, causing bad connections, but gold does not.
Because it isn't really a sales tax ban. If you have a physical presence in the state, you are still required to collect sales tax. Only interstate purchases are exempt, because of the difficulty in complying with all of the different sales taxes laws.
The ban that is about to expire is the one on taxing online services (such as ISP access). The "ban" on collecting sales tax over the internet is because of a law, but is the result of a court decision (which originally concerned catalog sales).
If you're looking for very small quantities, overseas vendors (relative to the USA) are the only way to go. I have used both of these, with excellent results:
Actually, they do. They don't buy the "blank" boards from Radio Shack (which does carry them, by the way), and they use fancier methods to etch them, but they do start with a copper-clad board.
The problem with that is that its not actually possible to write all zeros to the drive - no matter what data you send to the drive. (unless you happen to have software from the drive manufacturer that can send special commands to the drive to do it) A hard drive would not be able to accurately read the disk if it contained nothing but zeros, so it encodes the data. The encoding guarantees that there are some ones and some zeros actually written on the disk. So writing "all zeros" is not any better than writing random data, and is actually probably worse, because it generates a regular pattern that would be easier to filter out when someone tries to read your "erased" data.
No. At subsonic speeds, the air flow around an airplane is considered to be incompressable (density is constant). Once you go supersonic, really weird stuff starts happening (like flows accelerating in a diverging nozzle) due to the fact that air then behaves as a compressible flow. Bernoulli's law is still valid at both points, we just don't usually think about the supersonic case.
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Current RFIP solutions are based on silicon chips - which are dirt cheap! The silicon is so inexpensive, that the cost of the chips is insignificant compared to the rest of the device. The expensive parts are the off chip componants: the packaging, the antenna, etc.
The big advantage of the other techniques is that they are well suited to making large devices cheaply - like the antenna.
As other have mentioned, this is wrong. Silver is the best conductor, followed by copper, then gold. (see http://hypertextbook.com/physics/electricity/resis tance/ for more details)
What gold does do best is resist corrosion, which is why it is often used for connectors. Silver and copper both oxidize very rapidly, causing bad connections, but gold does not.
Because it isn't really a sales tax ban. If you have a physical presence in the state, you are still required to collect sales tax. Only interstate purchases are exempt, because of the difficulty in complying with all of the different sales taxes laws.
The ban that is about to expire is the one on taxing online services (such as ISP access). The "ban" on collecting sales tax over the internet is because of a law, but is the result of a court decision (which originally concerned catalog sales).
If you're looking for very small quantities, overseas vendors (relative to the USA) are the only way to go. I have used both of these, with excellent results:
Olimex - Bulgaria
MyroPCB - China
Some others that I haven't used personally:
CustomPCB - Malaysia
PCB Pool - Ireland
The only downside to these is the rather long shipping times.
For hobbyists there is one very good reason - price. Even a cheap homebuilt milling machine costs a lot more than some ferric chloride.
Actually, they do. They don't buy the "blank" boards from Radio Shack (which does carry them, by the way), and they use fancier methods to etch them, but they do start with a copper-clad board.
The problem with that is that its not actually possible to write all zeros to the drive - no matter what data you send to the drive. (unless you happen to have software from the drive manufacturer that can send special commands to the drive to do it) A hard drive would not be able to accurately read the disk if it contained nothing but zeros, so it encodes the data. The encoding guarantees that there are some ones and some zeros actually written on the disk. So writing "all zeros" is not any better than writing random data, and is actually probably worse, because it generates a regular pattern that would be easier to filter out when someone tries to read your "erased" data.
No. At subsonic speeds, the air flow around an airplane is considered to be incompressable (density is constant). Once you go supersonic, really weird stuff starts happening (like flows accelerating in a diverging nozzle) due to the fact that air then behaves as a compressible flow. Bernoulli's law is still valid at both points, we just don't usually think about the supersonic case.
The Who won by a bit of a landslide. =)