I make sure my browser doesn't "helpfully" remember any of my sensitive web site passwords (like my bank account login, for example.)
Otherwise someone could steal my computer and empty out my bank account in very short order.
It does take paying attention. Even after selecting "never for this site" for remembering my bank access password, one day I mistyped and was sent to the "you entered a bad password-try again" - and it offered to remember it again.
So if you steal a computer:
Go to every bank and credit card login site you can think of and see if the login information pops up.
After that, try entering some random password, and see if the login information pops up on THAT site.
After that, check out all the porn sites to see if they have accounts there...
No, I was building magnetometers - strictly analog sensor stuff. Flux transformers and Squids, integrated using YBCO. (For John Clarke at Berkeley)
Re:GaAs??? GaAs is material of the future...
on
Where's My 10 Ghz PC?
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· Score: 2, Insightful
Disclosure: on my day job I do design III-V chips, and I used to design superconductor chips up until recently, now trying to push that technology forward is more of a night job for me...;-)
I haven't been in the superconducter field for ten years now... what's the technology being used for the switches/logic gates?
As for GaAs, it's alive and well in the world of RF (analog) amplifiers going up to 100 GHz - I think the current technology uses a 6" wafer. (see, for example, WIN Semiconductor)
The power received goes as 1/r^2. So you're right - the figure of merit is power/distance^2, which in this case would be 5.24E-17 Watts/m^2. Which, if you think about it, is a factor of 4 pi off from the energy density at the receiver.
Note that it is possible to pick up a signal of any low power, in principal, by reducing the bandwidth (i.e. increasing the integration time). This was an on and off CW signal, which is very low bandwidth. The same setup could not have carried a voice conversation.
Despite the misleading figure of merit, this is still a pretty neat technical accomplishment. Even a very low bandwidth communications can be incredibly valuable. "Tidal wave coming in 1 hour", transmitted over 5 minutes, is clearly a very low bandwidth, but potentially very useful communication.
Ah. I think the crux of the disagreement is the difficulty of implementing the IF for generating spoofing of a GPS signal. You're contending that the IF generation is trivial enough that this hardware adds little to easing the problem of a GPS spoofer. If IF generation is easy, then clearly this board adds little to the problem.
Your point about the low bandwidth of the GPS satelite signal is well taken, and this specialized hardware is probably overkill for that purpose. I guess I was thinking about the supporting free software tools which may or may not yet exist for programming this thing, which could make it a remote controlled, stand alone GPS spoofer. The board appears to be about five inches across (if that is 100 mil header in the corner, anyway), so a complete system could be about 5"X5"X3". Depending on the software tools, this would certaintly aid me in building a GPS spoofer, but I'm not well rounded enough engineer to know if the IF generation could be easily implemented on another platform - a small computer running RTLinux, for example.
[And a dipole antenna is no more than 50% efficient in this case, as GPS uses circularly polarized signals;)]
The 50 MHz indicates the BANDWIDTH of the transmitter signal. It is easy to build a mixer and amplifier using off the shelf components (see www.minicircuits.com) to upconvert this signal to the GPS frequency band. You can buy an off the shelf (and cheap) GPS frequency range antenna - hell, pull one out of your existing GPS unit. An undergrad EE with one semester of RF design could build one for well under $100 in a day.
The point of this project is that it is very easy to take a signal and frequency shift it to a higher frequency for transmission (or a lower frequency for reception). Generating the unshifted signal is the hard part, and this board allows you to do it. GPS signals have a very low bandwidth, so 50 MHz is plenty to acheive this.
It's neither a receiver or a transmitter until you plug in a daughter board. It solves the hard part to the problem of GPS spoofing. An off the shelf mixer, power amplifier, and patch antenna do the rest.
If the intent was to only use it to 50 MHz, it wouldn't even be able to pick up "Classic Rock" (88.5 MHz around here).
It's inherently interesting that ANYONE is attempting to write a new OS. Technologically, however, I would not that their site seems to be completly slashdotted...
Another problem with everyone using GMT would be the day changing in the middle of waking hours. I have enough trouble making plans without my dinner being the day after lunch.
There's a reason the day changes in the middle of the night.
You actually can just work in the schematic as well, then generate the board. If you don't like the board, you can delete the board file and regenerate a new one. You have to place all the components again, though.
Also, eagle severely limits what can be back annotated from the PCB to the schematic - in fact, there seems to be very little that it WILL let you do in that direction.
I don't know when you last used eagle, but I've been using it for six months now and I've never had it crash. I've been very happy with it (and I tried the Protel demo), although circuit simulation is not important for what I'm doing.
One thing I like about eagle is that everything can be exported into a text based script - libraries, schematics, etc. This openness in the file format is one of the reasons I appreciate the software - if the source isn't open, at least the file formats are!
I was in a meeting with some people from a company that is developing SiC (Silicon Carbide) wafers and devices that is doing some work on GaN (Gallium Nitride). (SiC is good at very high temperatures and voltages and harsh environments. GaN is also very tough, but can be used at higher frequencies). One of the reasons they haven't pursued GaN devices very much is that it's a minefield of patents. There are so many patents on so many little aspects of GaN device development, that small players face a big risk trying to develop something. Only big companies with substantial patent portfolios (that they can cross license) and legal teams can really hope to develop something. Which is unfortunate, because a lot of the really good cutting edge work is done at small companies.
Unless someone comes up with something creative, GaN device technology will be hampered by the proliferation of minor patents.
This is even in the absence of dumb patents (like one click shopping) - these are patents for serious semiconductor work. In this case, stronger patent protections are hampering progress (to no one's benefit) rather than facilitating it.
Certaintly ever since Mother Jones swung so far to the right.
Seriously, if you think the NYT represents the views of the far or even moderate left in this country, you really need to get out and meet more people. Perhaps visiting one of the coastal states. I wouldn't go so far as to suggest northern California, but people are pretty friendly in New York and Massachussetts, and probably won't try to convert you to homosexuality if you say you're just visiting.
hmm, a hundred batteries capable of 10 AMPS or a hundred pairs of 10 AMP wire, which will be less problematic?
Easy - the wire. My house wiring has carried much more current than that for decades, and hasn't needed to be replaced. My car battery needs replacement every 5 to 10 years.
Slashdot Mirror
Frankly, I'm puzzled why zinc is on there - you can buy zinc lozenges with zinc pennies. Thhere's not much market for lead lozenges.
Remember, you're doing this on a stolen computer - give instructions for IE!
Otherwise someone could steal my computer and empty out my bank account in very short order.
It does take paying attention. Even after selecting "never for this site" for remembering my bank access password, one day I mistyped and was sent to the "you entered a bad password-try again" - and it offered to remember it again.
So if you steal a computer:
Go to every bank and credit card login site you can think of and see if the login information pops up.
After that, try entering some random password, and see if the login information pops up on THAT site.
After that, check out all the porn sites to see if they have accounts there...
Which is, what's the most expensive hardware you've ever ruined?
I own the screws holding it on - as long as you don't touch those...
No, I was building magnetometers - strictly analog sensor stuff. Flux transformers and Squids, integrated using YBCO. (For John Clarke at Berkeley)
I haven't been in the superconducter field for ten years now... what's the technology being used for the switches/logic gates?
As for GaAs, it's alive and well in the world of RF (analog) amplifiers going up to 100 GHz - I think the current technology uses a 6" wafer. (see, for example, WIN Semiconductor)
Note that it is possible to pick up a signal of any low power, in principal, by reducing the bandwidth (i.e. increasing the integration time). This was an on and off CW signal, which is very low bandwidth. The same setup could not have carried a voice conversation.
Despite the misleading figure of merit, this is still a pretty neat technical accomplishment. Even a very low bandwidth communications can be incredibly valuable. "Tidal wave coming in 1 hour", transmitted over 5 minutes, is clearly a very low bandwidth, but potentially very useful communication.
It's not starvation, but not as good as a law degree by far.
Your point about the low bandwidth of the GPS satelite signal is well taken, and this specialized hardware is probably overkill for that purpose. I guess I was thinking about the supporting free software tools which may or may not yet exist for programming this thing, which could make it a remote controlled, stand alone GPS spoofer. The board appears to be about five inches across (if that is 100 mil header in the corner, anyway), so a complete system could be about 5"X5"X3". Depending on the software tools, this would certaintly aid me in building a GPS spoofer, but I'm not well rounded enough engineer to know if the IF generation could be easily implemented on another platform - a small computer running RTLinux, for example.
[And a dipole antenna is no more than 50% efficient in this case, as GPS uses circularly polarized signals ;)]
The 50 MHz indicates the BANDWIDTH of the transmitter signal. It is easy to build a mixer and amplifier using off the shelf components (see www.minicircuits.com) to upconvert this signal to the GPS frequency band. You can buy an off the shelf (and cheap) GPS frequency range antenna - hell, pull one out of your existing GPS unit. An undergrad EE with one semester of RF design could build one for well under $100 in a day.
The point of this project is that it is very easy to take a signal and frequency shift it to a higher frequency for transmission (or a lower frequency for reception). Generating the unshifted signal is the hard part, and this board allows you to do it. GPS signals have a very low bandwidth, so 50 MHz is plenty to acheive this.
It's neither a receiver or a transmitter until you plug in a daughter board. It solves the hard part to the problem of GPS spoofing. An off the shelf mixer, power amplifier, and patch antenna do the rest.
If the intent was to only use it to 50 MHz, it wouldn't even be able to pick up "Classic Rock" (88.5 MHz around here).
2 Daughterboard slots hold any RF transmitter
4 High-Speed DA Converters (128 MS/s, 14-bit) to generate signals up to about 50 MHz (same chip as above).
It's inherently interesting that ANYONE is attempting to write a new OS. Technologically, however, I would not that their site seems to be completly slashdotted...
There's a reason the day changes in the middle of the night.
I could care less ... but it's hard to imagine how.
Also, eagle severely limits what can be back annotated from the PCB to the schematic - in fact, there seems to be very little that it WILL let you do in that direction.
One thing I like about eagle is that everything can be exported into a text based script - libraries, schematics, etc. This openness in the file format is one of the reasons I appreciate the software - if the source isn't open, at least the file formats are!
Unless someone comes up with something creative, GaN device technology will be hampered by the proliferation of minor patents.
This is even in the absence of dumb patents (like one click shopping) - these are patents for serious semiconductor work. In this case, stronger patent protections are hampering progress (to no one's benefit) rather than facilitating it.
How about Tom Lehrer?
Yup, I've known a few.
If I should die before I wake
All my bone and sinew take
Put me in the compost pile
To decompose me for a while
Worms, water, sun will have their way,
Returning me to common clay
All that I am will feed the trees
The plants, the fishes in the seas
When radishes and corn you munch
You'll be having me for lunch
And then excrete me with a grin
Chortling "There goes Lee again!"
--Lee Hayes
Certaintly ever since Mother Jones swung so far to the right.
Seriously, if you think the NYT represents the views of the far or even moderate left in this country, you really need to get out and meet more people. Perhaps visiting one of the coastal states. I wouldn't go so far as to suggest northern California, but people are pretty friendly in New York and Massachussetts, and probably won't try to convert you to homosexuality if you say you're just visiting.
Easy - the wire. My house wiring has carried much more current than that for decades, and hasn't needed to be replaced. My car battery needs replacement every 5 to 10 years.