http://www.stormcam.org/antenna-mmcx/
What is cheaper 2.4GHz wireless card?
What is the least expensive card? He must have an External Antenna jack preferably MMCX.
Looks like ZCOM for $ 69. http://wlanparts.com/product/XI-325HPPLUS Although not listed on the site of the factory ZCOM (http://www.zcom.com.tw/program/) Next would be the Senao for $ 99. http://www.austwireless.com/product_info.php?products_id=346 The Cisco product seems much more convincing, but it is double that in the 200 $.
Part 2 – Modify a Bluetooth USB to take External Antenna