It isn't really fair to expect a TV to cope with this sort of signal level as it isn't usually available from even an ambitious aerial system in a good signal area. Such levels can occur in cable TV and distribution systems, and of course, when people feel that with amplifiers, more is better!
Experimental setup is described here.
Return to loss/quality comparison
Selecting and siting your TV aerial
Aerial system components
Why DTT is different from an analogue install