A nice guy offered me his extra unit and I am (almost) up and running!
Before this I really had some difficulties I had to solve and I’ll post them here to help others.
First of all I could find the wifi network, from my Fritz!box ( Fritzbox) router/modem, but found out that was caused by my 2-in1 network combination of 2.4 and 5 GHz
Solution, before installing the WF first rename both networks f.e. Network2.4 and Network5
After that still no luck…
Although my USB power supply should deliver 1A, I didn’t trust it and replaced it by the one from my iPad and after that suddenly alot of networks popped up!
Solution: don’t use cheap USB power supplies!