PRESENTED is Serial No. N 7028, dated 1977 all around good condition, with no index error, and with a Carl Zeiss 4 x40 erect standing “Star” scope. It is missing the 6 x 30 inverting collimation scope which is of no practical use. Frequently, you will see this make sextant sold only with the inverting scope which is useless at sea in smaller size vessels, and was mainly used for doing Lunar distances, an archaic sight.
OVERVIEW: I have been particularly impressed with the
Russian CHO-T sextants as a good alternative to the premium brands such as both Plaths and Tamaya. It also makes sense to invest in one rather than plastic which commands very high prices for what they are, and any sextant with smaller mirrors.
In our opinion, Russian sextants are becoming better known in this country,
and there prices have been on the rise. This is because of their large mirrors, compact size, quality optics and overall good construction found only in the serious sextants. However because so many of them are sold with only scopes that show the image upside down they may not be a good buy. The design of the CHO-T has some features similar to the Freiberger, but is smaller, by almost one inch on the vertical measurement which makes it ideal on small vessels where space is a premium. Some of the parts, such
as mirrors and the tangent screw, are interchangeable.
Those who have used this model sextant at sea, speak very highly of it. If you are a small boat navigator make sure to keep the enclosed tangent screw free of salt water and lubricated with WD-40 and you will have no problems. You
also will welcome the light weight and full size mirrors of a CHO-T compared to other lesser
cost alternatives. The mirrors are font silvered and care should be taken in cleaning them. If possible they should be washed with fresh water, and gently wiped dry with tissue. Do not rub or you may scratch the surface.
The only Russian sextants we sell are those which have a scope that presents
the object in a manner familiar to navigators, not astronomers.
If not fitted with one, we carry new 3.5 x 40 scopes which we sell as an optional accessory. It fits perfectly, and has been purchased by many Russian sextant owners for this very purpose. Write us for details.
CONDITION: All parts are in good condition, and freely working. The horizon mirror is in “new”condition, and the index mirror was just replaced and the optics retuned by us. A $125.00 value. The adjustable index error is 1 minute “on the arc” and there is a smidgen of side error which helps define the celestial body. The case has been refinished attractively with a clear coat over the blond (Russian Spruce) wood rather than the typical light grey. It has rubber feet, shows slight use at sea, and has a few small scratches. The inside cover of the case is an inventory card in Russian, but NO INSPECTION CERTIFICATE which is standard with these sextants since they were built to a standard of less then 10 seconds of arc error making this of no consequence. The numbers and date, SN 81268, 1976, on the placard of the case do not match the sextant. The 4 x 40 monocular focuses on infinity, and the micrometer drum magnifier is attached. It has a iridium lighting feature when charged by an independent light source. Inventory item 4, a smaller screw driver is missing as are the set of extra mirrors. There are a few places on the frame where some paint has pealed off and has been refinished. This is strictly cosmetic and can be ignored.
OUR UNCONDITIONAL GUARANTEE:
If not completely satisfied with your purchase it may be returned, if without damage, within three days of receipt in its original condition and packaging. Return items must be insured for their full value. A prior email authorization by us for the return is required. Unfortunately, no refund can be made for the cost of shipping, packaging and handling unless we are at fault.
ADDITIONAL COMMENTS: This sextant is smaller than normal, and is a very handy size for a small boat navigator. Its index arm measures 7 7/8′ which is about 1/2″ less than most full size sextants. Its case is correspondingly
smaller. This should be an advantage to most people. The scopes are made by Carl Zeiss, a noted lens manufacturer. CHO-T sextants are made for the Russian Navy, and are typically seen in cases painted grey. Decent examples of this sextant are frequently seen on ebay and some have been sold for less than many inferior brands.
BUYING IN RUSSIA: The better examples are priced around $375.00 in Russia, and the typical freight charge to the U.S. is $90 or more, to this must be added the $45 wire transfer fee which will be charged by your bank. Most
of the those that we have imported were received broken due to inadequate packaging. There is no recourse. So expect to have landed costs of $505.00 plus duty and the aggravation of a trip to the bank, a long delivery time, and the risk of breakage.
This sextant gets our 4 1/2 Plus Star rating because it is missing the collimation scope, and its paint is less than perfect .
ABOUT SEXTANT TELESCOPES AND MIRRORS: For serious navigation, don’t buy a plastic sextant. You will be mostly shooting twilight sights of stars and planets where large size mirrors are very important. They capture more light and the object has a larger surface to stay on, so that it doesn’t jump off as easily. No plastic has anything close to the big mirrors on the preferred brands.
The right scope is very important, and for twilight sights a 3.5 x 40 or 4 x 40 are the preferred choices because of their ability to pass through more light rays, and the lower power minimizes movement. A scope more powerful than 7 x 35 is useless from small craft unless stabilized because it also magnifies your own movement and that of the celestial body making it seem to be jumping around,
Be careful if you decide to choose a Russian sextant that the scope’s image is NOT upside down. Many of them are astronomical in design.
DOES MY OPINION COUNT: We are one of the few company’s still selling navigation instruments that know anything about them. For purposes of judging whether my opinion counts, I was 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 also am a retired Master Mariner, and held a U.S. Navy “D” Qualification as a Senior Skipper – Oceans. From 1995 until 2001, I served as a Varsity Offshore Coach at the U.S. Naval Academy.
RUSSIAN CHO-T Drum Sextant SPECIFICATIONS:
Measuring Range:-5 to 140 degrees
Telescopes: 4.0
x 40mm: Coated optics and 6 x 30mm collimation scope with cross hairs
Frame: Lightweight die cast aluminum alloy with corrosion resistant light gray finish.
Vernier
Scale: reads to 1.0 min. Estimates to 1/10 min
Index Mirror: 56 x 42 mm. aluminized on the rear side.
Horizon
Mirror: 57mm diameter.
Shades:
4 for index mirror
3 for horizon mirror
Length of index arm: 7 7/8″
Weight: 3.3
lbs, 8 lbs in case
Carrying case: Clear coated wood case with placard – no key
INCLUDED ARE:
1 CHO-T Marine Drum Sextant frame
1 3.5 x 40 Scope – OEM
1 Mirror adjustment wrench
1 sextant case
1 wrench for removing the handle
1 90 degree angle devices
Rubber eye piece for scope
1 vale of oil
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. It is available at the University Library, all locations, of The California State University for free.
