starview-Extended cable can't get all channels

I have just purchased a second starview for the back room when scanning only getting half of channels I normally get in front room no problem. I used splitter and about 15 metre run of cable but as I say i get some channels including some of premium but on other box fed off same splitter get twice as many.
I have factory rest rescanned etc few times no joy, any advice would be appreciated

thanks

 

simple don't use the splitter