Thankyou for your suggestions and knowledge and sorry for the late reply.
Yes, I have a mobile but in the Scottish highlands even homing pigeons are slow.
Half meg line only for phone connectivity.
BUT... I purchased a 3 inch square "pocket hub" from EE for £15 a month...
THEN put it INSIDE a sealed plastic box
with insulation tape holding it closed
on top of a 20 foot piece of 2x2 inch wood beam
strapped to the side of the house
gave the elevation required for a constant 40meg connection with a USB feed coming back down into the base computer systems.
LAUGH if you will.... but it works. What put me onto the idea was the "tethering" suggestion. I just got to thinking out of the box and then put the hub INSIDE one.
Thanks again people. You saved yet another day.