http://www.radiolabs.com/products/wireless/waverv.php
I'm looking for a good antenna for wifi on my RV for a laptop computer. What do you think of this one?
It's got all the technical things there. Do they look good? Can it really reach out four miles like it said in Cruising World
magazine?

Cheers,
Ellen

"Ellen MacArthur" wrote in message
reenews.net...
http://www.radiolabs.com/products/wireless/waverv.php
I'm looking for a good antenna for wifi on my RV for a laptop computer.
What do you think of this one?
It's got all the technical things there. Do they look good? Can it really
reach out four miles like it said in Cruising World
magazine?

Cheers,
Ellen


They put the radio modem under an 8 dB omnidirectional antenna and run the
data signal down the USB cable.

One way link budget:

Tx power = +26 dBm
Tx gain = +8 dB
Rx gain = +8 dB (assume receiver is same as Tx)

Receiver sensitivity = -93 dBm @ 1Mbps data rate.

Link can tolerate path loss of 26 +8 + 8 -93 dB = 135 dB


Friis Equation:

Path loss (dB) = 32.44 + 20 log (km) + 20 log (MHz)

PL (dB) = 32.44 + 20 log (km) + 20 log (2450)

PL (dB) = 100 + 20 log (km)

135 - 100.22 = 20 log (km)

1.73 = log (km)

55 km = Link range.

I think their quoted sensitivity of -93 dBm may be too high. For a 1 Mbps
data rate assume a slope factor of 2.3 so Rx bandwidth is approx 2.5 MHz.

Thermal noise power at 273K is:

P = kTB k = 1.38e-23; T = 273; B = 2.5e6 Hz

P = 9.5 fW

P = -110 dBm.

Doesn't look like thermal noise is a problem. The noise figure of the front
end is probably 2-3 dB so it should go 4 miles and beyond.

Go for it, you can always return it if it's a pig.

Thanks, Gilligan. Your a dear. I don't understand all that technical stuff. Decibels are for
sound waves. I just can't figure out how they apply to radio waves when you can't even hear
them. But I just ordered one of the antennas. Anything's gotta be better than the weak little
antenna inside my laptop. Should I set the rate inside the card driver properties at 1 Mbps to
make it work the best?

Cheers,
Ellen


"Gilligan" wrote
|
| "Ellen MacArthur" wrote in message
| reenews.net...
| http://www.radiolabs.com/products/wireless/waverv.php
| I'm looking for a good antenna for wifi on my RV for a laptop computer.
| What do you think of this one?
| It's got all the technical things there. Do they look good? Can it really
| reach out four miles like it said in Cruising World
| magazine?
|
| Cheers,
| Ellen
|
|
| They put the radio modem under an 8 dB omnidirectional antenna and run the
| data signal down the USB cable.
|
| One way link budget:
|
| Tx power = +26 dBm
| Tx gain = +8 dB
| Rx gain = +8 dB (assume receiver is same as Tx)
|
| Receiver sensitivity = -93 dBm @ 1Mbps data rate.
|
| Link can tolerate path loss of 26 +8 + 8 -93 dB = 135 dB
|
|
| Friis Equation:
|
| Path loss (dB) = 32.44 + 20 log (km) + 20 log (MHz)
|
| PL (dB) = 32.44 + 20 log (km) + 20 log (2450)
|
| PL (dB) = 100 + 20 log (km)
|
| 135 - 100.22 = 20 log (km)
|
| 1.73 = log (km)
|
| 55 km = Link range.
|
| I think their quoted sensitivity of -93 dBm may be too high. For a 1 Mbps
| data rate assume a slope factor of 2.3 so Rx bandwidth is approx 2.5 MHz.
|
| Thermal noise power at 273K is:
|
| P = kTB k = 1.38e-23; T = 273; B = 2.5e6 Hz
|
| P = 9.5 fW
|
| P = -110 dBm.
|
| Doesn't look like thermal noise is a problem. The noise figure of the front
| end is probably 2-3 dB so it should go 4 miles and beyond.
|
| Go for it, you can always return it if it's a pig.
|
|
|
|

Ellen MacArthur wrote:
Thanks, Gilligan. Your a dear. I don't understand all that technical stuff. Decibels are for
sound waves. I just can't figure out how they apply to radio waves when you can't even hear
them. But I just ordered one of the antennas. Anything's gotta be better than the weak little
antenna inside my laptop. Should I set the rate inside the card driver properties at 1 Mbps to
make it work the best?

Cheers,
Ellen

Please let me know how it works out.
I need to tap into a wi-fi network here.

Thanks
Joe


"Gilligan" wrote
|
| "Ellen MacArthur" wrote in message
| reenews.net...
| http://www.radiolabs.com/products/wireless/waverv.php
| I'm looking for a good antenna for wifi on my RV for a laptop computer.
| What do you think of this one?
| It's got all the technical things there. Do they look good? Can it really
| reach out four miles like it said in Cruising World
| magazine?
|
| Cheers,
| Ellen
|
|
| They put the radio modem under an 8 dB omnidirectional antenna and run the
| data signal down the USB cable.
|
| One way link budget:
|
| Tx power = +26 dBm
| Tx gain = +8 dB
| Rx gain = +8 dB (assume receiver is same as Tx)
|
| Receiver sensitivity = -93 dBm @ 1Mbps data rate.
|
| Link can tolerate path loss of 26 +8 + 8 -93 dB = 135 dB
|
|
| Friis Equation:
|
| Path loss (dB) = 32.44 + 20 log (km) + 20 log (MHz)
|
| PL (dB) = 32.44 + 20 log (km) + 20 log (2450)
|
| PL (dB) = 100 + 20 log (km)
|
| 135 - 100.22 = 20 log (km)
|
| 1.73 = log (km)
|
| 55 km = Link range.
|
| I think their quoted sensitivity of -93 dBm may be too high. For a 1 Mbps
| data rate assume a slope factor of 2.3 so Rx bandwidth is approx 2.5 MHz.
|
| Thermal noise power at 273K is:
|
| P = kTB k = 1.38e-23; T = 273; B = 2.5e6 Hz
|
| P = 9.5 fW
|
| P = -110 dBm.
|
| Doesn't look like thermal noise is a problem. The noise figure of the front
| end is probably 2-3 dB so it should go 4 miles and beyond.
|
| Go for it, you can always return it if it's a pig.
|
|
|
|

"Joe" wrote
|
| Please let me know how it works out.
| I need to tap into a wi-fi network here.

I'll do a post just for you, Joe honey. I hope it finds lots of hot spots. Maybe I can get on some of
them for free. I think most truck stops have wi-fi. I don't know, just guessing, but Scotty would
probably know for sure. Most marinas have hot spots. But they're weak and they want you to
get a slip so they make them weak on purpose. A good antenna should let you get reception even
anchored far away from them. It would be good on my boyfriend's boat when we go on sailing
trips.

Cheers,
Ellen

Ellen MacArthur wrote:
"Joe" wrote
|
| Please let me know how it works out.
| I need to tap into a wi-fi network here.

I'll do a post just for you, Joe honey. I hope it finds lots of hot spots. Maybe I can get on some of
them for free. I think most truck stops have wi-fi. I don't know, just guessing, but Scotty would
probably know for sure. Most marinas have hot spots. But they're weak and they want you to
get a slip so they make them weak on purpose. A good antenna should let you get reception even
anchored far away from them. It would be good on my boyfriend's boat when we go on sailing
trips.

Cheers,
Ellen

If you are crusing S. Florida perhaps you will meet Capt. Neal. He's
been hacking Wi-fi's for years, and I bet his airstream can be seen
lingering around the truck stops.

Joe

"Ellen MacArthur" wrote in message
reenews.net...
Thanks, Gilligan. Your a dear. I don't understand all that technical
stuff. Decibels are for
sound waves. I just can't figure out how they apply to radio waves when
you can't even hear
them. But I just ordered one of the antennas. Anything's gotta be better
than the weak little
antenna inside my laptop. Should I set the rate inside the card driver
properties at 1 Mbps to
make it work the best?

Cheers,
Ellen

I think your system will set the optimum data rate on its own. It will work
fine at 1 Mbps.

If your laptop had an external antenna connector and you could keep the
antenna cable short, you can get some real range with a directional antenna
15 dBi gain. Presently, with my notebook, I can only hack about 1/4 mile
with its built in antenna. You can put the notebook in your car and drive
around town (especially near hotels and cafes) and use their access.