This video is one of 3 parts describing the homebrew MK5 3 band HF transceiver. It use parts that were left over from the MK4 project. It is designed as a backup rig for the caravan whilst going through the Australian outback. The main HF rig is the small but powerful IC706. However, the IC706 is very difficult to repair while travelling and so some form of backup is needed when travelling large distances to ensure there is some way of communicating in the event of a problem. So the homebrew rig, using standard components, is considerably easier to repair, and provide some sort of ability to seek help via the HF travelers network.