Topic: Keeping the dust/contaminants out !!
As the present design of the Nion allows TOO free a flow of air into the front panel, it would serve the unit's operational reliability in the long term if some kind of suitable/replaceable foam filter be designed and fitted right behind the Nion's front panel air vents. This would certainly help the units installed in difficult environments.
Just a simple feature request to help enhance the product's stability !!
Rgds.
AAPL