Welcome Mick,
The up side to your proposed solution is that it's cheap, just the cost of an antenna, a splitter/combiner and maybe some coax and connectors.
If you use an identical antenna, baluns and matched cables from the antennas to the combiner, you'll improve your chance of success. Still, the results may disappoint you. You may find multipath becomes a problem.
As a backup plan you may want to consider another option:
http://forum.tvfool.com/showthread.php?t=2882