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TDC Projector Heat filter problems
- From: P3D <Alan.Hancock@xxxxxx>
- Subject: TDC Projector Heat filter problems
- Date: Tue, 22 Oct 96 18:55:10 GMT
Have seen a post recently about TDC projector heat filters that are
fogged over, and that has prompted me to also request some help on the
same subject.
It is possible to polish off the white fog that appears on these filters
using metal polish or fine jewelers rouge powder mixed with water.
Unfortunately if the filter has had a lot of exposure to heat then the
surface can become fogged, cratered and ridged to an extent that the
filter needs replacing, which I am sure is now the case with many of
these old projectors.
I have being trying to locate some direct replacement heat filters for
my TDC 716 Stereo Projector for some time now. The size of the filters
in my unit are 60mm diameter x 3mm thick and fit in a carrier with two
recesses that are designed to take filters of that size, with a metal
clip to hold the filter in.
It is possible to get modern superior scientific quality KG1 or KG3 type
heat shield filters made in this size but this would normally be a
custom made size in the UK, and would cost in excess of US $150.00 a
pair. It is not possible to cut down a larger sized standard square or
circular filter because they are made to size then tempered, this helps
the glass to withstand up to 300C. Trying to cut such glass when
tempered would shatter it.
Does any one know of a source of this type of filter? I have tried all
the usual 3D supply catalogues and projector companies. The only
possibly viable suggestion I have had is from Bob Aldridge, to use 54mm
square RBT projector heat filters which should be available as spares. I
have not yet measured the light path width going through the filters,
but it should fit within a 54mm square. The heat filters are mounted
between the condenser elements to maximise beam width to spread out heat
dissipation over as large an area of the filter as possible. It should
be fairly easy to make up a different filter carrier to take RBT
filters, assuming they are suitable to dissipate the required amount of
heat.
If anyone has any information about possible sources of supply of
suitable heat filters or further information about their own heat filter
arrangements for TDC projectors, I would be pleased to receive any
information or ideas you may have.
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