Copyright 2004, 2003 by mymaryb2 and Joel
H. Jacobs, All rights reserved
I have
been a proponent of Russian sextants since I was first introduced to them,
and at this point have sold quite a few to satisfied
customers. They are well made and have a good
sturdy feel about them, and those navigators who have used them at sea have
found them to be reliable and accurate. The other noteworthy thing about Russian
sextants, and those made by Tamaya, are the excellence of their mirrors. They
are of outstanding quality. This sextant weighs only 2 1/2 pounds which is
much lighter than most and will be appreciated by those that take multiple
sights in series which is the recommended procedure. (The results are then
averaged.) The sextant's color is a very military looking shade
of grey-green which is common with the Russian Navy.
Since
these sextants are way under rated in the West, they represent a bargain for
those seeking a relatively inexpensive instrument with the same qualities of the
more favored brands such as Tamaya and the Plaths. They also represent an
outstanding alternative to
plastic, and those funky British ones, both with especially small
mirrors that sell for ridiculously high prices on
ebay .
Most of the Russian sextants
being offered on ebay come with scopes that present the image upside down and
are 7 Power. This design is commonly used for astronomical
observations by astronomers where it makes no difference when viewing the
heavens. This one was no exception, and the case is fitted only for this one
scope.
Astronomical scopes also have a much narrower field of view
which further limits their usefulness. You may wish to read my section devoted
to scope power which is below.
To use a sextant with this
type of scope requires that the user bring the horizon up to the celestial body
rather than bringing the celestial body down to the horizon. Even though this is
quite common with astronomical telescopes, the Russians are the only one's
using what is an astronomical design for contemporary sextants today. I
suspect that this is a carryover from a 100 years ago when Lunar Distances were
sometimes measured. I have tried it and found it to be unacceptable for these
reasons, and do not recommend it to any one trying to take sights from small
craft, learn CELNAV, or for that matter even experienced
navigators.
The only Russian
sextants we sell are those whose scopes present the object in a manner
familiar to navigators, not astronomers. So we have added a brand new 3.5 x 40
scope which we normally sell as an optional accessory. It fits perfectly,
and has been purchased by many Russian sextant owners for this very
purpose.
Presented here is a SNO-M type
sextant Serial No. 9001 without a date. The number that appears
on a plate on the box does not match, but the case is of the proper
type.
For those of you who have
the misfortune of owning or buying a sextant that you find you can't use, we
offer a 3.5 x 40 scope that fits perfectly, and we guarantee it or your
money back. If you want one let me know, and we'll offer it on ebay in a short
tem auction with a fixed BIN price of $120.00 plus S &
H.
CONDITION: This
sextant is in basically excellent condition considering its age. Some
paint has worn off on the arc outside the scale's readings, and is cosmetic
only. The index mirror has a thin line of corrosion along its inside edge which
is well out of the field of view. The horizon mirror's reflective surface is as
new There are no broken parts, and everything turns or moves
freely. Missing are a brush and screw driver which can be purchased
anywhere. The numbers on both sextant and case do not match. The case needs
some attention, and should be sanded and re-varnished. There is a Russian name
on its top. It has an unusual, positive mechanical hold down
clamp, There is no inspection certificate booklet.The booklet is rarely found
with their sextants. I do not find that to be important in contemporary
sextants because the error is so small as to be ignored in practical use.
Typical of all Russian sextants, the certificate on the inside lid of the case
is only an inventory of what's supposed to be in the case. As I said, Russian
Inspection certificates are in little booklets. I have never seen one that was
filled in. No illumination, again typical of this type. A copy of a SNO-M
booklet is included.
My RATING on this
sextant is FOUR AND ONE HALF STARS. Considering its age, I have no
reason to grade it down except that otherwise someone might
object.
ADDITIONAL COMMENTS: Russian
sextants are smaller than normal. They are a very handy size for a small
boat navigator. Its case is correspondingly smaller. This should be an
advantage to most people. The scope is said to be made by Carl
Zeiss, a noted lens manufacturer. There is no provision for a second scope.
The 7 power scope fits in the only
chock. SNO-M sextants are made for the Russian Navy, and are typically
seen in cases painted grey. This has been refinished and is varnished. You can
see the prices that Russian merchants are selling them for on ebay where
shipping to the States becomes a big expense at about $70.00 to
this must be added the $40 wire transfer fee which will be charged by your bank,
and their sometimes is a long delay in receiving them. This sextant
is shipped from S.E. Florida. The SNO-M frame is very similar to the
contemporary that of pre WW II C. Plath sextants and the Astra which
is made in China.
My opinion is based on
many years of seagoing experience as a celestial navigator, and include
serving as the editor
of the chapter on sextants of the 1977 Edition of "Bowditch", The American
Practical Navigator, NAVPUB 9; a member of the U.S. Naval Academy Navigation
Symposium Board, 1975-1978; the author of a book on marine sextants, Cornell
Maritime Press,1975, and the founding president of Nautech Maritime Corporation which
partnered with Tamaya of Japan in the introduction of the MS 733 Spica, the
MS 833, Jupiter, MS 933 Venus sextants and the famous NC-2 navigation
computer, in the U.S. market. I am also a retired Master Mariner, and hold
a U.S. Navy "D" Qualification as a Senior Skipper - Oceans. You can learn more
about sextants by visiting and reading about them in the sextants listed
in our ebay store. Go:
If you read the
following essay on sextant telescopes on someone else's auction, you should know
it is entirely my work product, and was taken from one of my previous listings
without my permission.
A READER ASKS A QUESTION about
scope power. Here's my response.
4 x 40 is considered a STAR Scope because
it transmits more light through the optics than higher powered scopes. Its
wider field of vision is an advantage in low light conditions.
7 x 35 and 7 x 50 are considered SUN
scopes because the higher power adds greater definition to the horizon and the
sun's limbs. It really makes for a precise LAN sight. On bright nights, they
work well with the moon. and can capture early rising planets at
twi-light.
As power increases, the ability to keep a
steady image decreases. Anything over 7 x 50, unless stabilized, has too narrow
a field of vision, and the image moves too much to be of much use from
small craft.
When given in the specs, Relative
Brightness, Relative Light Efficiency (adds 50% for coated lens to RB), and
Twilight factor are helpful in comparing the amount of light that reaches the
eye between various scopes.
For terrestrial objects, all you need is a
sighting tube, magnification is unnecessary because you need to be fairly close
in to shore to make out the objects and
identify them.
MORE INFORMATION - from the
internet from an unidentified
author:
"Here is what I know.
"I had the opportunity to use both of these types of
Russian(I should say Soviet)sextants.One was owned by a Polish ABS I served with
and he consistently got outstanding LOPs using his.He won an $1800.00 pool on
one transit when his final position was less than 0.2nm from the ships GPS pos.
when the evolution was stopped by the master. Both of these sextants types were
manufactured I believe in Riga,Latvia and someplace in East Germany between 1947
to 1988.
They were built for the Soviet Navy to rigorous
standards.They are clones taken from the Freiberger Prazisionmechanik Co.The
optics in the scopes were Zeiss optics.And as all Freiberger sextants are of the
Drum type.Very good quality machining, optics, very dependable and easy to
use.The Index mirror is standard size about 52 mm and I think also the silvering
is on the front face of the mirror.You will need to use cal. cylinders,dice or
dominoes to check perpendicularity of the Index mirror if that is the case.
The sextants I used were built in the ' 70's or early
' 80's.I can't say if there were instrument cal. sheets for these on the lids of
the boxes because I can't remember. All Freiberger sextants(man.after 1975)come
with a cert certifying they are free of Instrument Error for practical purposes
as do most sextants manufactured today.These Russian sextants are clones of
German Equipment.Cassens + Plath and Carl Plath sextants have a max. error spec
of 9" of arc over the arc's entire radius.Freiberger is right in there also so
your Russian sextant should be the same.
I would be more concerned about Collimation Error and
Index Error than Inst. Error.I wouldn't waste time and money trying to have the
arc calibrated.I had my MS-733 calibrated years ago at a good chunk of change to
find the whole error was 11" of arc.If you want it collimated there are many
places that will do that service for you."
Copied from a great site with lots of info on
CELNAV. Unsigned by its author. Here's the link.
http://www.i-DEADLINK-com/lists/navigation/0310/0050.html
RUSSIAN
SNO-M Drum Sextant SPECIFICATIONS:
Measuring Range:-5 to 140
degrees
Telescopes: 4.0 x 40mm: Coated
optics
Frame: Lightweight die cast aluminum alloy with corrosion
resistant light grey green finish.
Micrometer
Scale: reads to 1.0 min. Estimates to 1/5 min
Index
Mirror: 56 x 42 mm.
Horizon Mirror: 57mm
diameter.
Shades:
4 for index mirror
3 for horizon
mirror
Length of index arm: 8
3/4"
Weight: 2 1/2 lbs, 7 1/2 lbs in
case
Carrying case: Varnished light wood
(Spruce?) with placard - no
key
10 3/4 x 10 3/4 x 6 1/4 inches
INCLUDED
ARE:
- 1 SNO- M Marine Sextant
frame
- 1 3.5 x 40 NEW Scope, non
OEM
- 1 7 power scope OEM
- 1 Mirror adjustment
wrench
- 1 Varnished sextant
case
- 2 90 degree angle device
- 2 ocular lens shades
Please remember this is an
auction. We warrant and guarantee the accuracy of our statements,
and will willingly correct any of our own
mistakes.
International bidders welcome, but contact us
first. We have customers in Australia, Belgium, Canada, Chile, England,
France, Germany, Italy, Saudi Arabia, Spain, and the Eastern
Caribbean. The list is growing weekly.
Preferred payment by PayPal. Their credit card service
OK. Money Orders OK. Personal checks on U.S. banks only. Merchandise
will be held until cleared.
FULL RETURN
PRIVILEGES: This instrument is eligible for our warranty of
satisfaction on arrival. The winning bidder can return it within three
days of receipt if he is not completely satisfied. The only conditions are
that an email authorization be obtained, and that the instrument is
returned in its original condition and packaging, and be insured for
its full value. Unfortunately, shipping charges are not included in this offer
and are non-refundable.
SHIPPING & PACKING:
Due to the nature of this item, special protective packaging is used
for shipment. The cost of
shipping, packing, handling, and insurance to your destination, will
be calculated after the auction and is an additional charge. You may email us
before bidding to get these costs. We price shipping honestly, but
we do expect to be reimbursed for the nominal cost of packaging materials and
handling. The sextant we ship generally run between $22 - $27.50 depending
on the amount of insurance.
Copyright 2004,
2003 by mymaryb2 and Joel H. Jacobs, All rights
reserved
For those seeking more information
about the modern marine sextant, I suggest they get a copy of a book
written in 1975, now out-of-print. The Myths & the Truth about Selecting a Marine
Sextant. Cambridge MD: Cornell Maritime Press, 1975. 44pp, 10 illustrations.
Topics include scope power, mirrors, shade glasses, theoretical brightness,
accuracy, workmanship, accuracy, comparison of specifications. Softcover.
(16435) It is available at the University Library, all locations, of
The California State University for free.
A copy of this
book sold on ebay last year for $31.00, and that's not bad since it is
offered on the internet for over $125.00. A reprint can be ordered from
Amazon.com in hard or softcover. Prices start at
$38.00.
We are an AUTHORIZED
DEALER FOR NEW ASTRA SEXTANTS
