DD0KP Hi Heiner
I read the article about this possibility but thank you for mentioning it.
The power supply for feeding the LNB is no problem.
I made a Bais-T with the possibility to switch between 12V and 18V and it works great.
The original question was whether it would be wise to supply the LNB with voltage 24/7.
Given the answer I leave it as it is and as long as the LNB continues to work.
Attached some photos of the Bais-T i have made
For the POTY in focus of the 1.2M dish see my avatar
73's and tnx for reply