If you have a recent copy of S&T, JMI advertises in every isue. Just ask for the 2" Monorail Kit, currently 79.95. You can specify either a flat base or a radius base. The radius is perfect for a 12" id tube that you would probably use; the flat is for truss tube designs if you go that way.
I plugged your numbers into my version of newt and a 1.97" secondary will give 100% illumination over a a .16 diam, too small for even planets and the moon. A 2.14" diag give a barely adequate .385 coverage for 100%, I prefer at least .4~.5" coverage for the 100% cone. Naturally the 75% cone is bigger than you would ever need, but you have to get those minimums taken care of first.

• Explaination of 100% cone? - avecfort - May 21, 2001 - 13:36 UTC
  • 100% - bobmay - May 21, 2001 - 18:29 UTC
  • 100% ditto - walter - May 22, 2001 - 01:36 UTC
    • Suggestion? - avecfort - May 22, 2001 - 13:00 UTC
      • Diadonals, etc - walter - May 22, 2001 - 17:01 UTC
        • 24% of diameter obstruction by the secondary? - avecfort - May 24, 2001 - 07:40 UTC
          • Program for calculating contrast degredation by secondary size?? - avecfort - May 24, 2001 - 07:41 UTC
          • Secondary Obstruction - walter - May 24, 2001 - 20:52 UTC
            • Me thinks you're right :) - avecfort - May 25, 2001 - 05:03 UTC
              • Good Luck Building! - walter - May 25, 2001 - 12:03 UTC
                • Halmstad Sweden - avecfort - May 25, 2001 - 15:27 UTC