Bravia 46 works fine from a dvd, but on tv, the picture keeps breaking up with coloured patches obliterating parts of the picture and the sound misses bits. The old CRT tv works fine when plugged in to the same arial

You may want to try a signal booster,or a different arial.Not sure if your old CRT or arial was digital ,but you should have a tools button on your remote or a diagnotic option in your menu that will show signal strenght.I have a Terk HDTVo.It is a small bomarang shaped antenna that pics up stations 50 miles north (direction it is pointing)and the only issue is when storms roll thru.I have added a motorola 484095-001-00 signal booster and that has solved most of the issues with the farthest stations plus added a few more from different directions.You could also add a antenna and if your original arial is run with coax just use a diplexer to combine the signals.Well hope this helps and good luck.