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    Re: Mark 15 sextants
    From: Roger W. Sinnott
    Date: 2018 Oct 29, 15:07 -0400

    Thanks, Michael.  The telescope on my EBBCO (which is 45 years old) seems excellent for its purpose.  It is a Galilean type, about 2.5x, and I don’t see any chromatic aberration at all.  My problem is definitely the filters.

     

    Roger

     

     

    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Michael Bradley

    I've just bought an Ebbco, intending to use it as a class demo piece. . . .

     

     

    The snag for me is the telescope itself - there's a lot of chromatic abberation. If all your shades appear to have 'gone off', it may be the telescope that's the root cause.

    I've ordered a bit of 7/8" tube to make a sight tube, eliminating the telescope, I'll report back later ....

    Good sailing

    Michael Bradley

       
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