I get this new turbo pump of model V 81-M (Model 969-8903). It creates good vacuum and is cute.
The annoying thing is that it creates high frequency noisy which makes you headache. My supervise doubts that it lacks smooth oil or I mount it in wrong way. I mount it as parallel to the ground.
Is this normal? It works at 1350 Hz and 10 W. It's not warm at all.