I know much of this is old history, but I'm curious about what the original intent (and intended use) of the Per-lux lights may have been. Perhaps Scheinwerfermann or Alaric Darconville can dredge up some history, or maybe we have some old truckers here.
For years, I saw the louvered Per-lux 200T lamps mounted low on long haul trucks. I even bought myself a set of the smaller PAR36 Per-lux Fogcutters in the 1970s. I seem to recall Per-lux described their product as all weather safety lights.
Yeah, I know Grote owns 'em now, and there's a halogen version of the 200T lamp marketed. They seem to catalog both driving and fog lamps now.
But I'm thinking of the old PAR46 200T lamps (I have a set, used, and am thinking of mounting them for offroad use on my F250) and even the smaller PAR36 version. Come to think of it, there's a New Old Stock set of Fogcutters in the shed amongst my junk (let's hear it for eBay).
I seem to recall seeing them often on oncoming 18 wheelers on divided highways. If memory serves, the bulbs were of substantial wattage and perhaps a 50 degree beam spread. Were these used mostly as an auxiliary low beam? Or were they considered some sort of driving lamp? Typical mounting location suggests fog lamps.
They were fairly complex, using a shielded filament sealed beam, then a set of cast metal louvers and finally a clear outer lens. It seems considerable effort was made to avoid upward glare.
I have to remind myself that standard U.S sealed beam lights of the period were pretty lousy. Maybe truckers hoped the Per-lux lights would do what their low beams should have done.