Let me say something about the antenna connection through the adapter. You will notice with your new device that the digitally received sound quality is much better than the analogue from the house aerial. DAB+ is nothing other than the familiar analogue FM, simply transmitted in digital form. It therefore contains no background noise or interference. The clear digital signal makes listening to the radio with DAB+ much more pleasant for my ears than via the analogue signal from the house aerial, even with the throw antenna. However, since you like to listen to good music, I am sure that you will very soon use the good features of your device for the Internet.

Don't let the joy of your new radio be taken away from you. It is a very good device and will give you a lot of pleasure when everything is set up. Like all new devices in this price range, it is optimised for the Internet. Soon, you too will only be able to listen to the radio via the Internet. If you still want to use an adapter, this one might serve you:
Goobay antenna adapter (plug and connector)

There is an optical input - if that doesn't help, I would listen to the radio via the Internet, Ö1, Bayern, WDR, everything is available. And in very good quality!

The unit has only one connection for the supplied throw antenna. With an inexpensive adapter, you could probably also connect the house aerial to this connection (also 75 Ohm). How the unit selects the stations from the house aerial would have to be tested. This connection option was never an issue for me. I receive the stations with DAB+ and FM via the throw antenna flawlessly. Of course, an even larger selection of radio stations is available via the Internet.