2.4 Ghz 24dbi Grid Antenna No Signal!!

Hi,

I really need your help!

Iv just bought a 24dbi grid antenna with 12 meters of LLC400 Coxial cable from here :eBay Seller: wifilink uk: Networking, Computing items on eBay.co.uk

I am using a 200mw pci card to connect the antenna to bought from here:Find 200mW Wireless WiFi G/B Desktop PCI Card Jack & Antenna on eBay within PC Cards, USB, Adapters, NICs, Wireless Networking, WiFi, Networking, Computers Networking (end time 17-Nov-07 00:00:00 GMT)

The pci card has been bought from here originally: Alfa Network

The problem is that i am just about catching 2 or 3 networks even less than what I was catching with my USB cantenna which only cost me 20 pounds whereas this ended up costing me 70 pounds. So why is my signal so low? What should the range of my antenna really be?

I am using a low loss cable which has a loss of 0.22db per meter so the 10 meter cable shouldn't be a problem should it?

What am I doing wrong ? Please Help ME!! I really appreciatte any help!!

Thanks