The Cavelink provides through-rock communcations for deep camps.
Here is the manual
Internal name (limited to 8 characters) and number of each labelled unit.
For a basic set up the antenna is comprised of two metal plates earthed to the ground. For each unit the further apart the plates are the better and further the signal will travel. It is important that the plates are in good contact with the ground, use of water or wet mud is best for this. The routing of the wires in not important, but should not be wrapped round the spool. the wire has intermediate connection points if the full extent of the wire is not used. Multiple wires can be used to extend the distance. It does not matter which way round the wires are plugged into the unit.
For the best signal distance the (imaginary) lines between the antenna should be parallel in three dimensional space
The below instructions are starting from the front page, from anywhere this can be reached by pressing the can(cel) button until it is reached
The front screen has a line labelled inbox 2/3, this would be 2 unread of 3 messages
The cavelink set of stuff consists of all this in a blue plastic box