SKy HD box knocking out my freeview

[hudster]

Hello all

I've just moved into an apartment where a TV/Satellite/DAB socket panel was installed in the lounge by the original builders. I've taken the cover off and all 3 of these sockets are fed by a single core cable which runs up to the roof.

I've got Sky HD plugged into the Satellite socket, and a Sony freeview box plugged into the TV socket.

Sky works fine all the time, but the freeview box will only work when the Sky box is switched off (or on the main menu). My assumption is that the Sky box tuner is causing distortion on the cable which runs up to the roof, as this feeds both digitial signals.

The freeview box shows full signal strength until Sky is switched on, and then it drops down to almost zero and will show no channels at all.

Can anyone confirm if the Sky box is meant to do this, or suggest a solution please? It seems strange to me to have a single core cable for terrestrial/digital TV and Sky but I am no expert.

Thanks in advance!