eurovox picture and sound breaks up..plz help

hi and thanks 2 all who help..i have a eurovox and on certain channels, not all i get a bad signal the picture and sound breaks up.
i have tried my box round my brothers house and it works fine.i have put a 6mb atenuator in the aerial point this doesent help.also changed the scart leads to gold plated,this doesent help..any help would be greatful

 

Try a higher DB attenuator. http://www.beststuff.co.uk/coaxial_accessories.htm

9DB TO 12DB should do the trick.

 

thanks i will try that