Transmission power weak

Structure is simple, worked after 5 minutes ...
However, the transmission power is not particularly good. Were the bone in different rooms, I had virtually no reception (hence went back the product) and even though we have very thin walls (old building). Within the same space everything worked, but the TV picture when receiving Graet was very poor. Took me a little reminiscent of the early days of analog TV.
I think of satisfactory quality you must have access significantly deeper into their pockets ...