Can anyone recommend a sub-£50 specialist mains cable that improves TV pic quality (don't care about TV's sound cos I have an AV amp etc), please? I've tried a Tacima CS929 6-way mains conditioner (only £20.39 + p&p at Amazon; rrp £40), which made a spooky difference to my hifi (cleaner sound + improved spatiality/separation) but no difference to my TV & DVD pic. My TV is a plasma (Pana TH-42PX70). Thanks.