Dave Platt wrote:

The first thing that you ought to do, is check the specs and
literature for the WiFi radio (card, access point, etc.) you're
planning to use it with. Find out whether this radio was certificated
(i.e. tested for compliance by the manufacturer) with an antenna
having a gain level of 8 dBi or more.

If it hasn't - if the radio was only certificated with an antenna with
less gain - then you cannot use the MJF antenna with the radio, and
transmit, without violating the radio's Part 15 certification. You
would be transmitting illegally.

The horror...

If the Wifi card has a standard connector it should be OK with an
aftermarket antenna. If it has an oddball connector it must be used
with a specific antenna.

In any case, there is no one enforcing Part 15 compliance in the field.