Xternal antenna for the 12"powerbook G4
What you need is the original electronic nuts and GEEKS, They are called Hammers, Ham Radio operators, It is very EZ to make a passive repeater that clips on to the edge of the screen. It picks up the signal from the antenna running up the edge of the screen and ( repeats ) the signal out the attached antenna, all without an actual hard connection, The key is the signal wave length and after all the only problem is the close proximity to the Aluminum case. Find a Ham operator and Make His Day by showing him he is still usefull He (or she) can make you one in about 10 min, a nice one in about 30 min
also a Very minor mod to the battery flange can be done to accomidate a extra antenna pigtail if you can get a mac tech to get you one. You would run the wire out a small notch in the battery flange . use a file to make the notch 1/16" then you only need to connect the antenna to the pig tail. and the pig tail to the card as normal . If you can use a solidering iron , Great. If not , see a hammer