> -----Original Message----- > From: tclug-list-bounces at mn-linux.org > [mailto:tclug-list-bounces at mn-linux.org]On Behalf Of Mike Miller > Sent: Wednesday, January 16, 2008 11:50 AM > To: Brian Wall > Cc: tclug-list at mn-linux.org > Subject: Re: [tclug-list] [scalug] Zonbu laptops > > > On Wed, 16 Jan 2008, Brian Wall wrote: > > > On Jan 15, 2008 6:53 PM, Mike Miller <mbmiller at taxa.epi.umn.edu> wrote: > > > >> Another good thing about those XO laptops is that they have > very strong > >> WiFi built in. Apparently much stronger than ordinary laptops (the > >> secret is in the "ears," I'm told). > > > > Laptops sold in the US are limited in their antenna design by the FCC. > > So many mW of radiated power at x meters and so on. I wonder if the XO > > team fudged their wifi antennas, since these were not originally > > designed for sale in the US.. :-) "mW of radiated power" is not a limit on antenna design as such, it's a limit on transmitted power. Making the receiver's antenna separate and "hotter" is possible as one way to have an equivalent of more transmitter power. Most laptops have poor built-in antennas, so having good antennas and adjustable transmitter power may be better, since that takes care of some directionality issues that different antennas introduce. Something like a BIOS setting for time zone and country could be used to set the power. Most USA WiFi units don't seem to use the maximum allowed power. Some here have power settings, and some laptops recommend using the lower setting which happens to be the default as a way to save battery power. There is at least a 20:1 range in available transmitter power in different products here, according to a vendor's data table. > I doubt the FCC would allow that. I would think that the laptops sold in > the US would have to meet FCC requirements even if they were designed for > other countries -- so they'd have to partially disable laptops for US > sales. On the other hand, maybe they are within US FCC limits and most > competitors' laptops just aren't close to pushing up against the FCC > limit. The XO makers say that the antennae are the key -- most laptops > don't have antennae. Most USA units aren't close to the limits. I'd guess the average is about 1/10th max from product data I've seen. I've seen pretty wide variation in range from the 3 or 4 models of PCMCIA cards I've had, and similarly wide variation in PCI cards using their own antennas. I get such great range performance from the 3 types of internal mini-PCI cards in my Dell laptops (the Dell built-in antennas seem to be good) that I now generally prefer these to other WiFi stuff I've collected. BTW, I have 3 pretty hot Orinoco Gold a,b,g PCMCIA cards plus one PCI version of the same I want to sell and just haven't posted a classified yet. Linux drivers exist for these and may be on the driver CDs I have. The PCMCIA cards are new and unused OEM units, and the PCI is almost new. Probably will also sell my two Dell b cards (also Orinoco Gold) that have the external antenna connectors. Those are quite good on their internal antennas and great with various types of external antennas. Chuck