You had mentioned, I believe, mounting a wifi antenna "on the roof".
What were you feeding it with? I currently have the RF to USB device
mounted at the antenna and the down feed is a USB cable however it
appears that a length of more then approximately 10 feet results in
deterioration of the signal at the computer, and I assume the other
way also.

I have seen USB cables with built in amplifier. Did you use these and
do they require an external 5 VDC source? Or can the computer power
them?

My understanding is that at this frequency the coax represents a
significant loss and so have used only 5 -,6 inches of coax from the
antenna to the USB - wifi adapter with USB the rest of the way.

Suggestions???

Cheers,

Bruce
(bruceinbangkokatgmaildotcom)

On Fri, 16 Jul 2010 18:11:53 +0700, Bruce in Bangkok
wrote:

You had mentioned, I believe, mounting a wifi antenna "on the roof".
What were you feeding it with? I currently have the RF to USB device
mounted at the antenna and the down feed is a USB cable however it
appears that a length of more then approximately 10 feet results in
deterioration of the signal at the computer, and I assume the other
way also.

I have seen USB cables with built in amplifier. Did you use these and
do they require an external 5 VDC source? Or can the computer power
them?

My understanding is that at this frequency the coax represents a
significant loss and so have used only 5 -,6 inches of coax from the
antenna to the USB - wifi adapter with USB the rest of the way.

What you want is an antenna coupled directly to a Ubiquiti Bullet 2 HP
or something similar. Since the WiFi adapter is coupled directly,
there is virtually no feedline loss. The output of the adapter is
Cat5 ethernet cable which also suplies the power via a
Power-Over-Ethernet injector (POE). Cable length can be up to about
100 feet with no impairment.

http://www.amazon.com/s/?ie=UTF8&keywords=ubiquiti

Bruce in Bangkok wrote in
:

You had mentioned, I believe, mounting a wifi antenna "on the roof".
What were you feeding it with? I currently have the RF to USB device
mounted at the antenna and the down feed is a USB cable however it
appears that a length of more then approximately 10 feet results in
deterioration of the signal at the computer, and I assume the other
way also.


I'm feeding it with Cat5 Ethernet cable, which also provides DC power to
run the 200 mw router, located inside an upside down plastic bucket about
15 meters up the oak tree by my house. It's the wifi hotspot some of the
kids and American GIs on the Air Force base across the main road use
because the poor enlisted barracks has no wifi. It's my little gift to the
troops and some of the poorer kids in the neighborhood. Oddly, before
someone starts harping on it, I've never had any trouble from my users
though the hotspot is wide open to anyone in about a mile range to use. I
log the MAC of the users as the Cradlepoint router sends an email to me
from the router, itself, every day. I could, if necessary, lock out
whatever MACs were abusers, but rarely check it. I got plenty of bandwidth
on unlimited service.

There's no RF coming down from above. The whole station is in the bucket.

--
iPhone 4 is to cellular technology what the Titanic is to cruise ships.

Larry