Date:         Thu, 19 Apr 2007 22:45:10 -0700
Reply-To:     Michael Elliott <camping.elliott@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Michael Elliott <camping.elliott@GMAIL.COM>
Subject:      Re: External Wireless Amplifier
In-Reply-To:  <11dcddf80704191420t72a3d0a1h7c6a55d3e3e768f5@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

I'd say don't expect miracles. When the manufacturer says that this
product will "...expand the connection of your laptop up to 10 times the
current range of your notebook," you know that the marketing geniuses
have taken one spec (10 times greater transmit power) and distorted it
into another (10 times the range). It don't work like that. Every time
you double the distance it takes at least four times the power. In order
to increase the range 10 times would require a 100 times increase in
power -- This is the inverse square law. Standard wireless cards
transmit about 30mW, and this isn't a 3W product, so there's no chance
it will provide a 10 times increase in range.

Real life performance is probably a lot worse than that. CNET tested a
similar type of device, a 200mw high power wireless card and they found
that "...[it] delivered a signal capable of broadband speeds at
distances up to 150 feet. By comparison, most 802.11b PC Cards we've
tested reach about 100 feet before losing the connection. So what's the
secret? The card's increased range lies in its 200mW power output, a
substantial increase over the 30mW offered by standard cards"
(http://tinyurl.com/2e4zu8). A seven times increase in power provided a
50% increase in range.

The other half of the equation is the sensitivity of the receiver
portion of the card, too. It doesn't do much good to step up transmit
power if you can't "hear" the hotspot. There's nothing on the website
for the product that says anything about increased sensitivity. They do
describe the antenna as high gain, but don't provide numbers.

--
Mike "Rocket J Squirrel" Elliott
71 Type 2: the Wonderbus
84 Westfalia: Mellow Yellow ("The Electrical Banana")
74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
KG6RCR



Christopher Gronski typed:
> Hi All,
>
> Anyone got a wireless amplifier in thier van? I was thinking of
> getting one of these:
> http://www.radiolabs.com/products/wireless/waverv2.php?PHPSESSID=7a6b9719f1a107fbd81f3e0f4c4b9660
>
>
> Chris
>