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    Re: bubble sextant manual scanned, put on web
    From: Jean-Philippe Planas
    Date: 2006 Sep 7, 03:46 -0500
    Hello Paul,
    When you have time, it would be nice to put on line the Astrocompass sections as well as the sight reduction techniques and astro-navigation sections.
    Thanks again for this outstanding initiative.

    jean-philippe planas <jeanphilippeplanas@yahoo.com> wrote:
    Thanks a lot Paul for this excellent job. This is the exactly the kind of information I had been looking for for ages and never dare ask.

    Paul Hirose <cfuhb-acdgw@earthlink.net> wrote:

    I have scanned the "Sextants" section of Air Force Manual 51-40, "Air
    Navigation" (1955 and 1960 editions) and posted it on my little web
    site. This is good info for owners of U.S. bubble sextant models A-10,
    A-14/AN5851-1, A-15, MA-2, and Kollsman periscopic. The MA-1 pendulous
    mirror sextant is also covered.

    The page is 990 k, but 95% of that is the images. If you have a slow
    connection, it may be best to turn off graphics in your browser, read
    the text, and individually download the images you want.


    My new HP C3180 did the scans. It's a combination inkjet printer,
    flatbed scanner, and copier, priced at $100. This is my first experience
    with a scanner. As far as I can tell, this unit does a good job,
    especially considering its low price. To input text, I scan it in black
    and white mode and request the output as a .txt file. (OCR software is
    bundled with the unit.) Then I paste that into an HTML editor and clean
    up the OCR typos by hand. The biggest problem by far is that a hyphen at
    the end of a line invariably causes letter doubling. E.g., ad-ding (with
    a line break after the hyphen) comes out as "addding". Nevertheless,
    this process is enormously more productive and accurate than hand typing.

    Some of the "typos" are exactly what the original says. For example, the
    periscopic sextant section has a true heading formula: TH=TB-8RB [sic].
    I haven't fixed those mistakes, since my objective is to accurately
    reproduce the original.

    The C3180 can produce *much* sharper scans than the images on the web
    page, but more resolution means slower page loading, especially for
    users on dial-up. In addition, the physical size of some of the images
    on the screen becomes annoyingly large. So, I set the resolution just
    high enough to generate adequate images, and some I omitted entirely
    when I felt the text was understandable without them.

    It's fortunate that AFM 51-40 is loose pages bound by metal clips. The
    book comes apart easily. I imagine conventional binding would cause a
    lot of trouble getting the pages flat on the glass.

    I may put more of this manual online. If you have a burning desire to
    see a particular topic, speak up. I have only one volume from the 1955
    edition, but all three volumes of the 1960 edition. It captures an
    interesting time in air navigation. The sextant, astrocompass, and
    4-course radio range are in there, but so are VOR, TACAN, and Doppler.

    I block messages that contain attachments or HTML.

    Get your own web address for just $1.99/1st yr. We'll help. Yahoo! Small Business.

    Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates starting at 1¢/min.
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