The ERP is the Effective isotropic Radiated Power, or in other words, the amount of power that would be required to produce a uniform spherical radiation pattern having the same magnitude as that of the peak of a non-isotropic or directional radiation pattern. TV antennas are just big dipoles, and the radiation pattern looks something like a doughnut. They don't waste power radiating straight up into the atmosphere or down into the ground below the antenna. The ratio of actual radiated power to EIRP for a dipole is something like 1/20, so you would adjust the FCC ERP numbers down accordingly before adding transmitter inefficiency back in.
... assuming it's ALL running at the same time you only have 22-23KVA less than half of what a 200A circuit provides...
And then, of course, the refrigerator comes on while you simultaneously blow dry your hair, vacuum the floors, and watch your 60" HDTV.
In other words, I completely agree with your point. 200A service should be overkill for just about anything shy of a mansion or a family of 12. You would have to live in a part of the country with very cheap electricity to have all of your major appliances be electric in the first place. Though, as with too many things in life, you have to regulate for the lowest common denominator. Plan for the worst and hope for the best, etc.
I think you may be confused. 100A service is the minimum service allowed under the 2008 National Electric Code. I doubt any electrician will install a 100A panel in a home which has at least one 220V electric appliance in addition to the air conditioner (oven, clothes dryer, etc.). As I said, it would be only under extreme circumstances that a single family home would saturate a 200A service, but the service is indeed there (at least for the majority of homes built within the last two decades).
200A service (2 each 120V x 100A lines) is standard for new construction these days, even for smaller single story homes of less than 1000 sq. ft. With this, a home could draw 48000W, which while extremely high as an average load, is not too far from impractical as a peak draw if the home has electric appliances.
Re:Fiber's still the wave of the future
on
100 Gbps Via Ethernet
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· Score: 3, Interesting
This (Infinera) is the company that makes complete wavelength-division multiplexed optical systems on a chip. They have demonstrated 40 Gbps x 40 channels = 1.6Tbps in development and currently have many 10 Gbps x 10 channel networks deployed by companies such as Level 3 (which first came online in 2004.)
Also, the limiting factor in single optical channel transmission is not the transistors at each end. The real problem is the laser modulation at the transmitter as well as the response of the photdetector at the receiver. GaAs or InP transistor circuits at either end are more than capable of handling speeds in excess of 40Gbps if the laser generation/detection ever gets there.
I have used MCE 2005 for about a year now. I have two HDTV tuners and a single standard definition cable tuner in the machine, and it has always handled them beautifully. This on a modest Athlon XP 2400+ mobile chip, using the onboard sound on an Asus board. The largest headache with rolling your own HTPC is getting the right blend of hardware and drivers, but if you do a little research and plan your purchases accordingly, the DVR software packages that are out there right now provide a great television experience, including MCE. The picture quality will depend on the MPEG decoders that you use, and properly configuring your graphics card for the type of display you are driving. Building your own HTPC is not for the technophobic, and for this reason you can buy OEM Media Center PC's from several vendors, but the software and hardware ARE there TODAY that are stable and easy to use IF you have the right skillset and are willing to put some time into overcoming the initial learning curve. If you don't like Microsoft products on principle, there are plenty of alternatives: MediaPortal (open source), MythTV (open source, linux), BeyondTV, SageTV, GotAllMedia (free), GB-PVR (free), MeedioTV, etc. I have played with about half of these, and they all worked fine, ONCE I got my hardware rock solid. Having said all this, if you don't need the extra functionality of an HTPC (music, movies, games,...), you probably aren't into tweaking anyway, and should just buy a tivo.
I like to think I was somewhat of a carPC pioneer, and I have been through several iterations (the first one, a quick proof of concept hack, ran on a 486dx motherboard with two 500mb drives). Since then I have changed hardware several times, but always used regular 3.5" desktop hard drives, with no extra shock absorption of any kind, and have never experienced a failure. As a matter of fact, my faith in modern hard drives has been strengthed by my experiences. In particular: On cold winter mornings the hard drive bearings scream for the first minute or so, and on really cold days the drive won't start at all until the car warms up a bit, but it always comes back to life. For a while I had the drive in a cheap removable drive bay that was mounted vertically. When going over a large bump such as railroad tracks, the drive would lose its connection, the music would stop and you could hear the drive spin down, but as soon as it reseated it would spin back up and the music would pick up where it left off (much like a cd player).
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The ERP is the Effective isotropic Radiated Power, or in other words, the amount of power that would be required to produce a uniform spherical radiation pattern having the same magnitude as that of the peak of a non-isotropic or directional radiation pattern. TV antennas are just big dipoles, and the radiation pattern looks something like a doughnut. They don't waste power radiating straight up into the atmosphere or down into the ground below the antenna. The ratio of actual radiated power to EIRP for a dipole is something like 1/20, so you would adjust the FCC ERP numbers down accordingly before adding transmitter inefficiency back in.
... assuming it's ALL running at the same time you only have 22-23KVA less than half of what a 200A circuit provides ...
And then, of course, the refrigerator comes on while you simultaneously blow dry your hair, vacuum the floors, and watch your 60" HDTV. In other words, I completely agree with your point. 200A service should be overkill for just about anything shy of a mansion or a family of 12. You would have to live in a part of the country with very cheap electricity to have all of your major appliances be electric in the first place. Though, as with too many things in life, you have to regulate for the lowest common denominator. Plan for the worst and hope for the best, etc.
I think you may be confused. 100A service is the minimum service allowed under the 2008 National Electric Code. I doubt any electrician will install a 100A panel in a home which has at least one 220V electric appliance in addition to the air conditioner (oven, clothes dryer, etc.). As I said, it would be only under extreme circumstances that a single family home would saturate a 200A service, but the service is indeed there (at least for the majority of homes built within the last two decades).
200A service (2 each 120V x 100A lines) is standard for new construction these days, even for smaller single story homes of less than 1000 sq. ft. With this, a home could draw 48000W, which while extremely high as an average load, is not too far from impractical as a peak draw if the home has electric appliances.
This (Infinera) is the company that makes complete wavelength-division multiplexed optical systems on a chip. They have demonstrated 40 Gbps x 40 channels = 1.6Tbps in development and currently have many 10 Gbps x 10 channel networks deployed by companies such as Level 3 (which first came online in 2004.) Also, the limiting factor in single optical channel transmission is not the transistors at each end. The real problem is the laser modulation at the transmitter as well as the response of the photdetector at the receiver. GaAs or InP transistor circuits at either end are more than capable of handling speeds in excess of 40Gbps if the laser generation/detection ever gets there.
I have used MCE 2005 for about a year now. I have two HDTV tuners and a single standard definition cable tuner in the machine, and it has always handled them beautifully. This on a modest Athlon XP 2400+ mobile chip, using the onboard sound on an Asus board. The largest headache with rolling your own HTPC is getting the right blend of hardware and drivers, but if you do a little research and plan your purchases accordingly, the DVR software packages that are out there right now provide a great television experience, including MCE. The picture quality will depend on the MPEG decoders that you use, and properly configuring your graphics card for the type of display you are driving. Building your own HTPC is not for the technophobic, and for this reason you can buy OEM Media Center PC's from several vendors, but the software and hardware ARE there TODAY that are stable and easy to use IF you have the right skillset and are willing to put some time into overcoming the initial learning curve. If you don't like Microsoft products on principle, there are plenty of alternatives: MediaPortal (open source), MythTV (open source, linux), BeyondTV, SageTV, GotAllMedia (free), GB-PVR (free), MeedioTV, etc. I have played with about half of these, and they all worked fine, ONCE I got my hardware rock solid. Having said all this, if you don't need the extra functionality of an HTPC (music, movies, games,...), you probably aren't into tweaking anyway, and should just buy a tivo.
I like to think I was somewhat of a carPC pioneer, and I have been through several iterations (the first one, a quick proof of concept hack, ran on a 486dx motherboard with two 500mb drives). Since then I have changed hardware several times, but always used regular 3.5" desktop hard drives, with no extra shock absorption of any kind, and have never experienced a failure. As a matter of fact, my faith in modern hard drives has been strengthed by my experiences. In particular: On cold winter mornings the hard drive bearings scream for the first minute or so, and on really cold days the drive won't start at all until the car warms up a bit, but it always comes back to life. For a while I had the drive in a cheap removable drive bay that was mounted vertically. When going over a large bump such as railroad tracks, the drive would lose its connection, the music would stop and you could hear the drive spin down, but as soon as it reseated it would spin back up and the music would pick up where it left off (much like a cd player).