Actually it is the University of Colorado. Several regional schools follow the same switch in abbreviation including KU, MU, NU, and OU. Each are the "University of" their respective states.
All of the original Big-8 schools without a "state" in their names reverse their initials. Colorado, Missouri, Nebraska, and Oklahoma are CU, MU, NU, and OU respectively. There is no UC Boulder. It is CU Boulder.
Except that 1/0.3937 is not 2.54. The difference is approximately 0.00000508001016009. It is simply a matter of scale to find a conversion where this would cause a problem.
you're a US surveyor. In that case, according to U.S. standards set in 1893 and 1959, you should use:
1 inch = 100/39.37 centimeters. This is approximately 2.54000508001016.
For details, see:
http://www.wsdot.wa.gov/Metrics/ftmtr2.htm
There are two valid conversion factors: the 1959 standard linking the inch to the cm as in 1 inch = 2.54 cm exactly, and the previous standard (1893) that is used in US surveys and that defines the foot in terms of the meter as 1 foot = 12/39.37 meters.
The full story is here: http://www.wsdot.wa.gov/Metrics/ftmtr2.htm
The NIST article correctly makes the distinction that the leap seconds are inserted to account for the earth's rotational period, not its orbital period.
The AP story got it completely wrong.
Having an integrated GPS unit in your car (not sliding around on or velcroed to the dash) with an integrated external antenna is really valuable. It would cost at least $250 to install an equivalent system and even then it would not look as nice. The speculation about voiding the entire auto warranty is FUD. You can remove your entire stereo system and destroy it without jeopardizing the warranty on the rest of the car.
However this is only half of the hack. Someone needs to learn how to unlock the cellular phone so that people can independently buy service. Then you could dial in to your car to track it, unlock it -- all the same things as onstar.
The field strength appears to be reasonable. First a quick calculation for the power density at 30 cm from a 1 Watt transmitter transmitting isotropically:
This is in the ballpark. Once the factor for the phone's antenna gain (~2 dB) is included, it's close to the stated 30 V/m. I'm guessing that you are not measuring your ham rig from 30 cm while you're transmitting (of course is wouldn't make sense to try and measure HF from that short distance anyway).
After reading through the test results, there is some room to question the applicability of the results to a real aircraft, namely:
1. The avionics used in the test are not the newer models that are required to have better EMI rejection. They are certified to an older standard that is more susceptible to interference. 2. A passenger is very unlikely to approach within 30 cm of the avionics equipment without any obstruction that would mitigate the interference.
Additionally, no further attempts are reported to determine the mechanism for the interference. In the test, the navigation signals the instruments use are injected directly via cable into the devices' antenna ports. The interfering signal is transmitted at the devices using a horn antenna. Therefore one can presume that the interference is not entering the device via the RF section but instead through the housing, power connections or some other route. But which is it? Are the power connections poorly sheilded?
Sending letters to users of Linux is like Honda stealing trade secrets from Ford on how to build a certain engine, me buying a Honda, and then getting a letter from Ford letting me know that I may be in violation of something.
It's exactly like that, but with these additions: not only did you get your Honda, you also got the plans for it and you have the ability to produce them yourself and make a profit from delivering them.
In that case, I think Ford would be justified in sending you a letter.
The radiated power that makes it outside the bulb is likely very low. Remember, these devices are designed to save power versus a conventional incandescent lamp, not hose the spectrum with wasted emissions. Has anyone seen any real numbers that could form a basis for estimating the interference potential? Measurements have been made on similar lighting devices, see:
http://www.its.bldrdoc.gov/pub/ntia-rpt/99-366/
These measurements were made with the receive antenna ~ 0.5 meters from the device.
These bulbs are extremely bright, and are designed to light factory floors, stadiums, and other large areas where the devices likely will be a factor of 20 or more (36 dB) farther away.
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Actually it is the University of Colorado. Several regional schools follow the same switch in abbreviation including KU, MU, NU, and OU. Each are the "University of" their respective states.
forgot the University of Kansas: KU.
All of the original Big-8 schools without a "state" in their names reverse their initials. Colorado, Missouri, Nebraska, and Oklahoma are CU, MU, NU, and OU respectively. There is no UC Boulder. It is CU Boulder.
As do all of the original Big 8 schools without a "State" in their names. NU, OU, KU, MU, and CU.
Except that 1/0.3937 is not 2.54. The difference is approximately 0.00000508001016009. It is simply a matter of scale to find a conversion where this would cause a problem.
you're a US surveyor. In that case, according to U.S. standards set in 1893 and 1959, you should use: 1 inch = 100/39.37 centimeters. This is approximately 2.54000508001016. For details, see: http://www.wsdot.wa.gov/Metrics/ftmtr2.htm
There are two valid conversion factors: the 1959 standard linking the inch to the cm as in 1 inch = 2.54 cm exactly, and the previous standard (1893) that is used in US surveys and that defines the foot in terms of the meter as 1 foot = 12/39.37 meters.
The full story is here:
http://www.wsdot.wa.gov/Metrics/ftmtr2.htm
The NIST article correctly makes the distinction that the leap seconds are inserted to account for the earth's rotational period, not its orbital period. The AP story got it completely wrong.
Having an integrated GPS unit in your car (not sliding around on or velcroed to the dash) with an integrated external antenna is really valuable. It would cost at least $250 to install an equivalent system and even then it would not look as nice. The speculation about voiding the entire auto warranty is FUD. You can remove your entire stereo system and destroy it without jeopardizing the warranty on the rest of the car. However this is only half of the hack. Someone needs to learn how to unlock the cellular phone so that people can independently buy service. Then you could dial in to your car to track it, unlock it -- all the same things as onstar.
The field strength appears to be reasonable.
First a quick calculation for the power density at 30 cm from a 1 Watt transmitter transmitting isotropically:
Power_density = 1 Watt / (4 * Pi *(0.3 meters)^2)
= 0.884 Watts/m^2
Field_strength = Sqrt(Power_density * Z_o)
= Sqrt(0.884 Watts/m^2 * 120 * Pi Ohms)
= 18.26 Volts/meter
This is in the ballpark. Once the factor for the phone's antenna gain (~2 dB) is included, it's close to the stated 30 V/m. I'm guessing that you are not measuring your ham rig from 30 cm while you're transmitting (of course is wouldn't make sense to try and measure HF from that short distance anyway).
After reading through the test results, there is some room to question the applicability of the results to a real aircraft, namely:
1. The avionics used in the test are not the newer models that are required to have better EMI rejection. They are certified to an older standard that is more susceptible to interference.
2. A passenger is very unlikely to approach within 30 cm of the avionics equipment without any obstruction that would mitigate the interference.
Additionally, no further attempts are reported to determine the mechanism for the interference. In the test, the navigation signals the instruments use are injected directly via cable into the devices' antenna ports. The interfering signal is transmitted at the devices using a horn antenna. Therefore one can presume that the interference is not entering the device via the RF section but instead through the housing, power connections or some other route. But which is it? Are the power connections poorly sheilded?
It's exactly like that, but with these additions: not only did you get your Honda, you also got the plans for it and you have the ability to produce them yourself and make a profit from delivering them. In that case, I think Ford would be justified in sending you a letter.
The radiated power that makes it outside the bulb is likely very low. Remember, these devices are designed to save power versus a conventional incandescent lamp, not hose the spectrum with wasted emissions. Has anyone seen any real numbers that could form a basis for estimating the interference potential? Measurements have been made on similar lighting devices, see: http://www.its.bldrdoc.gov/pub/ntia-rpt/99-366/ These measurements were made with the receive antenna ~ 0.5 meters from the device. These bulbs are extremely bright, and are designed to light factory floors, stadiums, and other large areas where the devices likely will be a factor of 20 or more (36 dB) farther away.