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I'm a proponent of the USSR SNO-T.  It is a copy of the Friberger.
Has excellent rigidity and has the lowest backlash of any sextant I've
used.  They are readily available on ebay for $250 - $325.  I
purchased one mine from India and had good results.  I believe this
sextant is a better value than the Astra and can be had for about the
same price if not less.  I suggest you ask Bill for his opinion of the
SNO-T, I am very satisfied with mine.

Given that, I have the following advice.  Purchase a copy of Bill
Morris's (Nav list menber) "The nautical sextant".  Covers just about
any sextant ever made and he is an excellent surce of information.
Take your time, don't just rush out and purchase a 2nd sextant - the
one you have is quite usable.


Keep practicing with the Davis MK25.  It is a very usable sextand and
wil give you lots of experience learning how to use a sextant.  A
couple of pieces of information on the Davis if you haven't already
figgured them out.

1) Always approach the sight from the same direction (either
decreasing the reading or increasing the reading).  Never go past
coincidence with the horizon and then correct by going back the other
way (unless you go quite a bit past).  The reason is the Davis has
extreme backlash.  Try measuring the indes error comming from
different sides of zero to find out exactly how much.

2) Temperature stability.  The mechanism may bind with changes in
temperature.  Le the sextant come to temperature B4 measuring.  Check
IE between measurements and do not correct for IE each time.  With a
bit of practice (and patience), you can come quite close to the
accuracy of the better sextants.
Quoting Philippe Posth :

> The best sextant is the one used by the best user.
>

[Note from FER: A reminder to one and all. The sextant is properly
referred to as a SNO-T, not a "SNO-T" (unless you use proper Russian
Cyrillic characters, which only one NavList member has done). I will
continue to edit posts which use anything but SNO-T to refer to this
type of sextant.]

   

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