anyone using a wlan parabolic grid antenna?

I've bought a wlan grid antenna and I suspect it might be faulty. I've got it connected to
my PCI wireless card and I can't pick up a thing with it. Even my little plastic usb stick
picks up a couple of AP's but the grid - nothing. Yes I know the grid is directional. I've
tried contacting the supplier but had no response yet.
To those that may be using a grid antenna there was just one question I'd like to ask:
what it the resistance across the terminals on your antenna cable? ie: if you connect an
ohm meter to the cable pin connector housing what resistance do you get? On mine I get a
short circuit, no resistance at all and I don't know whether this is correct or not. I may
have a faulty antenna. The antenna spec cheet states 50ohm nominal input impedance.
I've got several other dinky wlan antennas and I tested all of them and they are all the
exact opposite - maximum resistance, not the slightest hint of continuity. I need to work
out if this grid antenna is faulty or not. Thanks for any feedback.

The 50 ohm rating is at 2.4 Ghz. You are measuring DC resistance. An antenna will normally read open circuit to ground, but if there is a coil or transformer in the antenna assembley the DC resistance will be close to zero even though the 2.4 Ghz impedance is 50 ohms. On the other hand if you pick up no signal no matter how the antenna is oriented the antenna is likely bad.

tg wrote:
>
> I've bought a wlan grid antenna and I suspect it might be faulty. I've got it connected to
> my PCI wireless card and I can't pick up a thing with it. Even my little plastic usb stick
> picks up a couple of AP's but the grid - nothing. Yes I know the grid is directional. I've
> tried contacting the supplier but had no response yet.
> To those that may be using a grid antenna there was just one question I'd like to ask:
> what it the resistance across the terminals on your antenna cable? ie: if you connect an
> ohm meter to the cable pin connector housing what resistance do you get? On mine I get a
> short circuit, no resistance at all and I don't know whether this is correct or not. I may
> have a faulty antenna. The antenna spec cheet states 50ohm nominal input impedance.
> I've got several other dinky wlan antennas and I tested all of them and they are all the
> exact opposite - maximum resistance, not the slightest hint of continuity. I need to work
> out if this grid antenna is faulty or not. Thanks for any feedback.

--
Mike Walsh

"Mike Walsh" <spam_sucks@bellsouth.net> wrote in message
news:484DAC13.E61B0688@bellsouth.net...
>
> The 50 ohm rating is at 2.4 Ghz. You are measuring DC resistance. An antenna will
> normally read open circuit to ground, but if there is a coil or transformer in the
> antenna assembley the DC resistance will be close to zero even though the 2.4 Ghz
> impedance is 50 ohms. On the other hand if you pick up no signal no matter how the
> antenna is oriented the antenna is likely bad.

ok thanks for your response Mike