did you install the driver on the CD that comes with the card? the
updated driver seems not working well with netstumbler

i bought those airlink cards about a year ago and havent done any
modification. i did pop the USB plastic case open and saw two antennas
on this card. the external seems to be the TX and the one on PCB i
think is the RX... it has different antenna configuration than its PCI
counterpart, but the USB has a different chipset, the rt73 (vs rt61)
which i suspect having better receive sensitivity

so the perfect mod would be replacing the external antenna with a
reverse polarity SMA connector and hook it up with

a) yes, a very high gain omni or directional antenna
b) or an external amp, like the popular and available hawking HSB2
that can put out 500mW and comes with a 2dBi omni

Frys is having HSB2 on sale for $69.... for antenna, i would look for
one on eBay or other websites... i just can't stand the ridiculous
prices that they set on those simple devices at local electronics
retailers, even at Frys... despite the fact that i dont have enough
skill and too lazy to build one

i am not sure how this set up would work for MIMO design, as the
AWLL5025 specification says that it has diversity antenna
configuration... meaning it assigns TX to one antenna and RX to
another. This mod would probably improve just the TX side and leave
the RX side at the mercy of the chipset's RX sensitivity

but the AWLH4030 is a different story. it has one single antenna for
both TX and RX... so i removed the antenna and hooked it up to a
hawking HSB1 (yeah i've got the version 1 of the HSB) set the amp to
500mW, snapped in a 9dbi omni and ran wildpackets omnipeek. From my 2nd
floor apartment, i can see a wifi hotspot from a nearby scottish inn,
which is about 1.5 miles away as the crow flies.... by the way, the
setup is entirely indoor and done in my desk in the living room, and
no, there's no clear line-of-sight to any of the networks i was able to
"see" with this setup

contrary to popular beliefs, and politics, an external wifi amplifiers
does boost the receiving side of the radio it hooks up to, provided
that one single antenna is being used..... from my experience, the
Hawking HSB1 and HSB2 are bi-directional, output 500mW of TX power and
provide a +12dB RX gain, are relatively inexpensive and work well with
both OFDM and DSSS in half-duplex mode ...

my next wifi adventure would be buying another HSB, hook them up in
series, that would theoretically give me a +24dB boost in RX gain while
maintaining the output TX power within legal limit... i cant wait to
see how far my hotrod wifi toys can reach...

cheers

miso@sushi.com wrote:

> Mine (USB ralink) didn't work with netstumbler. :-(
>
> I opened mine up and yanked the antenna. I cut some hardline with a SMA
> on one end and plan on mating the two. It looks doable. [The idea is it
> is cheaper and better to use a USB cable to position the radio rather
> than have the loss in the coax.]
>
> I also built a new biquad using what might be a time saving trick.
> Instead of trying to shove coax into copper pipe to do the feed, I cut
> the top (threaded part) off of a female to female N adapter with a
> hacksaw. Now I have N connector and a feed in one step. I cut a hole in
> the copper plate using a cheap ass Harbor Freight stepped drill bit.
> [The drill bit set is about the only good thing I ever bought there.]
>
> I made the loop as a circle rather than having corners. Get copper wire
> and mark out two sequential segments 122mm in length. Don't start from
> the end, but give yourself some working room so you can grab the free
> end of the wire. I then wrapped the wire around a PVC adapter that was
> close to the proper diameter to get the shape. Then you bend the wire
> in the center to form one common point of the biquad loop. Trim the
> wire at the other marks and solder to the center feed of the hacked N
> to N adapter. Yeah, I'll get around to photographing this. Next up is
> fitting it to a Direct TV dish. [I couldn't find the Echo Star dish.]