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    Re: Site details
    From: Bill Morris
    Date: 2008 Nov 28, 11:15 -0800

    There shouldn't be any backlash with an A10, as it is provided with a
    backlash spring. The index bearing after 60-odd years is often in need
    of lubrication to ensure free movement (I once had one completely
    seized). The bearing can be difficult to pull apart and reassembling
    with the anti-backlash spring correctly tensioned can be a trying
    exercise. You can probably improve the index error by setting the
    instrument to a sea horizon, removing the read-out counter, setting it
    to zero (allowing for dip) and replacing.
    I will be covering these and other details in an e-book on A10
    restoration, due out at the end of February. It will be along the
    lines of my e-books on the reconditioning of the Mark IX series bubble
    sextant and my "Naked Nautical Sextant". See www.sextantbook.com for
    details. Meanwhile, you can contact me off line about your A10 if you
    Bill Morris
    On Nov 28, 4:08�pm, bruce hamilton  wrote:
    > All times GMT 27 Nov 2008
    > A-10 Sextant with 31.5' index error off the arc (horizon reading is lees
    > than zero in case if am mixed up)
    > Sextant has no other calibration. I frequently get LOP's within 2 miles
    > of my AP so I am happy. It has backlash so I try not to change
    > directions. �I suspect some other error as stars with higher altitudes
    > tend to give me bigger errors.
    > I am actually quite surprised that I am getting a fix that is close
    > enough to find the airport (or Bermuda) if I had do. I have an A-12 and
    > Mark IX, but I only drag out one an evening.
    > Thanks
    > I am presently using CelestNav 3.0 for the palm pilot to work out the
    > sites. I would appreciate any comments on the program. I like it for
    > everything but the fix calculation, but I think 3.0 is only a Beta.
    > AP 49d �16.1 N �123d 7.1 W
    > Pollux � 06:19:33 � 27d �59.3'
    > Vega � �06:16:31 � 13d � �0.3'
    > Betelg � 06:10:53 � 28d �44.3'
    > Altair � �03:56:11 � 22d �37.0'
    > Vega � �03:54:45 � 32d �06.9
    > Capella 03:52:46 � 39d �35.7'
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