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    Re: Kollsman periscopic pendulous sextant
    From: Gary LaPook
    Date: 2008 Sep 1, 00:01 -0700

    My last post did not come out right, I quoted Paul Hirose who we must
    thank for scanning in AFM 51-40.
    
    gl
    
    On Aug 31, 9:00 pm, "Gary J. LaPook"  wrote:
    > Gary LaPook wrote:
    >
    > You do not need 28 volts to illuminate the Kollsman periscopic sextants.
    > All you need are a couple of Caltronics number 328 miniature lamp light
    > bulbs which are the same size as the 28v bulbs originally installed in
    > the sextant but which operate on 6 volts. I made up a 6 volt power pack
    > for mine using 4 AA batteries which I attached to the back of the
    > averager with velcro. You can also use bulbs designed for 12 volts thse
    > are Caltronics number 330. You could then make a power cord to use a
    > cigarette lighter socket for power.
    >
    > 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.http://home.earthlink.net/~s543t-24dst/airnav/index.htmlMy 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.
    >
    >          More options Sep 6 2006, 10:07 pm
    >
    > From: Paul Hirose  ---.net>
    > Date: Wed, 06 Sep 2006 22:07:03 -0700
    > Local: Wed, Sep 6 2006 10:07 pm
    > Subject: bubble sextant manual scanned, put on web
    > Reply to author
    > 
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    >
    > Paul Hirose 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.
    >
    > http://home.earthlink.net/~s543t-24dst/airnav/index.html
    > 
    >
    > glap...---.net wrote:
    > >That is exactly what is used with the A-10 sextant, 4.5 volts from
    > >three size "D" batteries. If you have one of the more modern Kollsman
    > >sextants that use an electronic averager you do need to supply 28
    > >volts to the averager since they won't work on less. For use in an
    > >airplane, you can make a 28 volt power suppy with one integrated
    > >circuit and a small amount of soldering. The IC converts 12 volt DC to
    > >28 volt DC and costs about $25.00. I made one and can find the source
    > >for this IC if anybody wants to do the same. You can also get 27 volts
    > >out of 3, 9 volt batteries wired in series. This works fine for the
    > >lights but the averager uses about 150 ma so these betteries don't
    > >last long powering up the averager. And they are expensive.
    > >You can also replace the 28 volt bulbs, or in your case the 3 volt
    > >bulbs, with 6 or 12 volt bulbs that are the same size and power them
    > >up with other battery combinations or with a cable to your lighter
    > >socket in the plane. If anybody needs the source for these other bulbs
    > >I can find it again. I think I posted all of this information on bulbs
    > >and on the IC about a year ago so you can probably search the archive
    > >for it also.
    >
    > >gl
    >
    > >On Aug 31, 6:56 am, werner  wrote:
    >
    > >>Actually my Kollsmans are Euopean license builds (1 from Kollsman-
    > >>Germany and the other 2 from Kollsman-UK, and had been used in the
    > >>respective air forces). Those sextants have a 3 Volts lighting system.
    > >>28 Volts only go into the gimbal aircraft mount. Within it the voltage
    > >>is transformed into 3 Volts to go into the sextant. The usual method
    > >>(when not installed in an aircraft) is to use a modified flashlight
    > >>(instead of the bulb there is a connector for a cable) with 3 D-cells
    > >>(flashlights were provided in the storing case).
    >
    > >>Werner
    >
    > >>On 31 Aug., 04:49, glap...---.net wrote:
    >
    > >>>BTW, if you need a 28 volt power supply for using your sextant at home
    > >>>just go down to Home Depot and buy a water sprinkler system electric
    > >>>transformer which puts out 28 volts and is cheap.
    >
    > >>>gl
    >
    > >>>On Aug 27, 12:12 pm, werner  wrote:
    >
    > >>>>Hi,
    > >>>>Has anyone a manual for this sextant? I need one for the "non-bubble"
    > >>>>type, but with the pendulum. I have three of these sextants (two good
    > >>>>ones, one needs overhaul).
    >
    > >>>>Thank you.
    >
    > >>>>Werner
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