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    Re: Using star-star distances
    From: Hewitt Schlereth
    Date: 2008 Sep 24, 11:45 -0400

    George, thank you for your (typically)  thoroughgoing response. It's
    nice to know someone who's actually used an Ebbco. Your experience
    with it agrees with mine.
    My original Ebbco was bought in the early 70's and was the model with
    the small mirrors and is identifiable because it has two shades for
    the index mirror. In '75 I got the newer model which has larger
    mirrors and three shades for the index mirror.
    A few months ago I found one of these on eBay.uk and got it for $36
    (plus freight of $25). It's shades were all opaque and the stains on
    them suggested to me that the damage was caused by storing it wet with
    salt water. (I used to rinse mine in the galley sink when it got salt
    water on it). The mirrors on the eBay.uk sextant were a little  frizzy
    around the edges, but by transferring the shades from my Ebbco that
    needs a horizon mirror clip, I have a workable sextant. I've checked
    it here in St. John and it's giving me positions 1 to 2 miles from a
    known spot.
    Thanks again. I'm off to check out Plastimo.
    On 9/24/08, George Huxtable  wrote:
    >  Hewitt Schlereth wanted to find parts for his Ebbco plastic sextant, and Ken
    >  Gebhart wrote about John Weatherlake, who produced the original Ebbco
    >  sextants in his garage at Wargrave, Berkshire, England, ending-
    >  "Any information you may have, as a countryman of Mr. Weatherlake, will be
    >  appreciated."
    > Well, closer than just a couuntryman, we're only half-an-hour's drive apart
    >  (or a passage of two days down the Thames), being in the same county, until
    >  they shifted the boundary and moved us from Berkshire into Oxfordshire, .
    >  But I've never met him or seen his garage operation.
    >  Ken has it right, the Ebbco is now the  "Antares" model of Plastimo, a
    >  French company; they took it over several years ago. I don't know where they
    >  are actually made, now. It's in their catalogue at plastimo.co.uk, listed,
    >  curiously, under "Electronic navigation". It  looks just the same as the
    >  Ebbco product, but I've  seen one behind a glass window only. Plastimo have
    >  several US distributors. I doubt if they will supply bits and pieces, in the
    >  way that Ebbco would.
    >  I've owned a couple of Ebbco micrometer sextants in my time, and even an
    >  original Vernier model when I started sailing. Strengths and weaknesses have
    >  been listed before on this list and its predecessor, but for new readers,
    >  here they are again. They apply to the Ebbco version; the Plastimo Antares
    >  may or may not be the same. My present model is around 15 years old.
    >  For-
    >  Light, and easy to use.
    >  Stable and reproducible (to a minute or less, I've found). The rack was
    >  claimed to be machined into the plastic frame, rather than moulded, and I
    >  believe that.
    >  Claimed to be calibrated to within an arc-minute. That, I've never checked,
    >  thoroughly, but have found no reason to doubt it.
    >  When it's dropped on the cockpit grating, it just bounces. This has been
    >  checked (inadvertently) a few times.
    >  Against-
    >  Not very rigid. If you grip the handle over-tightly, you can shift one image
    >  (sideways) a bit with respect to the other (it comes back when you release
    >  the pressure). It's so light to hold, there's no call for such tight
    >  gripping.
    >  Not being skeleton-construction, as are most metal sextants, there's quite a
    >  lot more windage, and you can feel some buffeting in a strong breeze.
    >  The shades are a weak point. Presumably made as a photo-film sandwich, they
    >  can delaminate internally over the years, and then show a split-line where
    >  they have done so (though that doesn't seem to result in observable
    >  refraction).
    >  One of the adjusting screws bears on the back of the index mirror through
    >  its silvering, and over time leaves a spot on it. Poor design, there.
    >  Some light can get into the telescope around the edges of the shades, though
    >  it's easy to cobble-in a bit of baffling to intercept it.
    >  The mirrors and field-of-view are small, by modern standards.
    >  If having dropped it, you then tread on it (as happened to me once when my
    >  boat lurched), that sea-boot can end its days!
    >  =================
    >  You can often find secondhand Ebbcos on the British ebay, at ebay.co.uk  ,
    >  under "sextant" rather than "sextants", in the range of �10 to �20 (about
    >  US$ 20 to 40) There are two up there at present.
    >  For ordinary altitude navigation (but NOT for lunar distances), I rate the
    >  Ebbco as a very practicable tool.
    >  George.
    >  contact George Huxtable, now at george@hux.me.uk
    >  (switched from george@huxtable.u-net.com)
    >  or at +44 1865 820222 (from UK, 01865 820222)
    >  or at 1 Sandy Lane, Southmoor, Abingdon, Oxon OX13 5HX, UK.
    >  >
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