VM Box, single SCART and digisender
 

I have just taken as VM package (TV, internet, phone) and cannot find how to make a digisender work properly through the single SCART socket. I have a SCART socket box which I have plugged both the digisender and TV into. Both work but the reception on the remote TV is very poor.
Is the answer a 'through socket' like used on the AEI X7?
Would swop digisend for X7 but X& is 2.4 GHz where the digisender is 5.8 GHz so interference with Virgin router possible.