Thread: 4" f15 Refractor build with questions?
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Old 25-11-2015, 11:20 PM
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Merlin66 (Ken)
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Join Date: Oct 2005
Location: Junortoun Vic
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David,
Re the white light/ PST changeover... remember the PST etalon must be positioned at -200mm from the prime focus.
This may affect your thoughts on the length of the OTA.
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