Question about Yamaha R-N803d

The antenna supplied must be mounted on my window, otherwise nothing works. Our house is built earthquake-proof with a lot of iron. I bought a small special antenna that amplifies the signal with electricity and can be placed behind the unit without any problems.

I have a "no name" product from a competitor. If I look at the products here at Digitec, then a HAMA DAB/DAB+ antenna with power supply (Fr. 38.80) would definitely come into question, it looks identical in construction to mine.