-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on
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30mm long 4 x 3.7mm internal bore light tunnel that is made of 4 pieces of surface silvered 1mm glass slips. Goes between the high power lamp and the first lens of the optics proper. The silvering is half "burnt" ? off one and 1/4 burnt off the other 3. Any reason why not to replace with some polished stainless steel 0.5mm sheet, formed around square bar and packing, into a rectangular tunnel? There is a 3 inch fan cooling the bulb and a 2 inch fan cooling this tunnel, and upwind of both fans, also cooling the main ps.