How can i fix my AV tv transmitter, ferguson, 3030T?

I recently bought a av transmitter to be able to watch sky tv in bedroom. Not sure if product is faulty but lost my receipt so trying to get it to work. I have set up the transmitter with scart to sky box and receiver is attached to bedroom tv with scart in the av slot. After trying this while both on the same channel i am picking up a very poor siginal and the main tv picture with the transmitter disapears and cant change channel through the receiver. Please if anyone has advice?