The link to the Optus 3G tower proved a challenge that required a fair bit of extra gain. This is a picture of the home-brew Yagi used.
Veroboard isn't the neatest way to build circuits, but it's cheap, quick and easy. See the electronics here.
The circuit isn't complex as most of the magic is done in the ARM computer and microcontrollers. Have a look at the schematic diagram here.
Man and machine must cooperate in order to get this thing up a small hill.