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    Problems with artifical horizons
    From: Alan S
    Date: 2012 Mar 20, 13:29 -0700

    I have two of the things, one being the Davis AH, people here are likely familiar with this device.

    I also have a home made AH, first surface mirror, 10" x 10", on a levelable base. I level the assembly using a couple of string levels and reasonably fine leveling screws 120 degrees apart.

    This afternoon, I'm in the Pittsburgh area, I did a couple of sun shots with the Davis AH sitting on the ground. IE was 1.8 Min On Arc. Measured angles were 90 D 48 Min, and 90 D 25 Min, without correction. Time was around 1430, Eastern Daylight Savings Time. Nothing further wad done, that is the sights were not reduced.

    I next brought the mirror AH out for an airing. Setting is on the ground, leveling the unit, I saw reflected sun, but could not find sextant sun, that would be the sun that moves when the index arm is swung.

    I next tried setting the mirror ah on an elevated surface, using an ironing board, which is about 40" high. After leveling the assembly, I tried a sun shot, rocking the sextant while swinging the index arm. Reflected sun was visible, but alas could not find the sextant sun.

    I assume that I'm doing something wrong, but cannot figure out what that might be. Anyone here got any bright ideas or suggestions?

    Thanks in advance for same.


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