Dr Boer at the University of Twente says that you can mount these mini-whip antennas on a conductive or non-conductive mast.
Whether the mast is conductive or not hardly matters for the reception.
He further goes on to sayWhat if the mast is not conductive? The amplifier will still measure the potential difference between the plate and the "ground" of the amplifier circuit. If the mast is not conductive, then the only thing connected to the circuit ground is the shield of the coaxial cable. In that case, the potential difference will be measured between the plate and whatever that cable shield goes to. If the cable shield is solidly connected to ground somewhere further on, it will work just as well as with a grounded mast.
http://www.pa3fwm.nl/technotes/tn09d.htmlif the mast is non-conductive, making a connection between the cable's shielding braid and a ground electrode.
Would I be right in thinking the grounding of the cable's shielding would be done from the bottom of the non-conductive mast?
i.e. the coax runs from the antenna down the non-conductive mast, then at the bottom of the mast I ground the cable shielding with an earth stake?