[Russell Boaler]

The inner workings of the cable drum are as per the attached pictures.

The wiring from the radio comes into the inside of the drum via the hollow mounting shaft and attaches to two grooved brass rings cast into a Bakelite housing. This housing is fixed to the mounting shaft with a small grub screw. My housing was shattered so I had to patch it back together and re-build the missing bits with some fibreglass.

Two spring loaded braided wire loops run in the brass grooves which attach to a pair of spring loaded terminals mounted in a Bakelite mount which are accessible on the outside of the drum. The drum body can spin freely on the mounting shaft and the wire loops running in the groove maintain a constant electrical connection.

I haven't figured out how the wiring that would be wound on to the outside of the drum would be connected to the spring loaded terminals... seem a bit odd as there's no means of a positive mechanical connection (like a threaded terminal and a couple of nuts would offer). Any ideas on how the wires might be connected would be appreciated... a couple of small hose clamps maybe???