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Old 10-10-2018, 09:54 PM
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mental4astro (Alexander)
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mental4astro is offline
 
Join Date: Jun 2008
Location: sydney, australia
Posts: 4,979
David, this is going to make your wheels spin!

Instead of letting your Mak cool, rather DON'T let it cool!

The problem that cooling introduces is the metal tube cools quickly, leaving the air inside the tube to create a temperature gradient between the metal tube and the baffle/primary mirror, and this produces the tube currents.

By insulating the OTA, you don't allow the metal tube to cool too quickly, there by not creating a temperature gradient between the tube and the internals of the OTA, and hence no tube currents.

A few of us have started doing this to our Maks. The insulation can be as simple as a black yoga mat! And the rolled up mat is made such that it extends over the corrector lens just like a dew shield, making it duel purpose. And the result is immediate with no waiting time between set up to observing. This has been done from 6" Maks to 9" Maks.

Alex.
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