This is the layout on the inside, with the power amplifier module and 12v regulator attached to a 1/8 x 4 piece of aluminum angle used as a heat sink.

I installed a small chipset fan, thinking that I might need a little airflow at full output on hot summer days at the antenna range, but it really isn't necessary. The ventilation holes drilled into the side of the top cover seem to be enough.

The PC board is held to the heat sink and chassis with 4-40 screws. Note the 2 near the RF module; these are placed to ensure a solid RF ground between the board and the amplifier IC.

Most of the parts on the board are SMT, though there are a few leaded parts sprinkled in there as well.