In that case you need 2 routers ,R-1 in top of the mast with a (sensitive)
internal or external antenna having one of its ethernet ports connected to
an ethernet port of the second wireless router R-2 serving as a wireless
bridge and fitted lower on the mast ,having a not so sensitive antenna but
sufficient for communication with any wireless router or adapter inside
the house/shack.
R-2 should be set to communicate on an 'extremity' channel say channel 13
,which will hopefully not be needed by R-1. This to avoid that the 2
routers 'bite' each other .

A (wireless) router is a bi-directional input-output device .
When the wireless side is receiving it passes the information on to the
ethernet port serving as output and vice versa.

Hope the above makes sense



Surely all you need is a wireless card in the pc that you wish to connect to
the router on the mast. If you happen to have a router in the house as well
it is no different to your next door neighbour having a WiFi network. You
just connect to whichever router you wish to.

Jeff