I was thinking about changing tactics and fitting a loft aerial that I
can fit / adjust myself, but i`m not sure whether I might need to
consider a higher spec aerial than might normally be required if it was
mounted outside.




Take a look at the TLC aerials, they have one high gain version, just make
sure you buy the correct band .... check the IBA site to find out what your
transmitter is - and whether you need to set for horizontal or vertical
polarisation.

Rick