How can I reduce the static noise which is a loud high pitch buzzing when for example the picture has a light back ground. It doesn't happen when the picture is in darker colours.

Sounds like your TV has a fault, is the picture clear?

Have you tried retuning the channel using the manual fine tune option? The buzz aftern caused by the sound channelling picking up the interfarme informating for the picture which it should not do if it tunined correctly. One possible casue of this is if the signall from the TV station your watching is too strong does it only accour on one station or all stations? Canbe fixed by attenuating the signal but Ino idea where you purchase an TV signal attenuater in Bangkok if that where you are. Does another TV plugged into the same anntenna point have to same issue?