How to manufacture the coils.
The coils are wired round 30 mm nylon bolts.      
    The connection between wire and antenna segment 
            is done through a bit of welding wire.This is first soldered 
to the antenna segment.When this has got cool,
the nylon bolt is threaded on to the tube, and the
wire of the coil can be soldered without any       
melting of the nylon.
       Here above you can see, how the bottom coil is made.