NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
SNO-T/CHO-M + Freiberger info
From: Doug Royer
Date: 2003 Oct 6, 17:07 -0700
From: Doug Royer
Date: 2003 Oct 6, 17:07 -0700
Courtney,welcome to the list.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 consistantly got outstanding LOPs useing 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 beleive 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 Instument Error for practical purposes as do most sextants manufactured today.These Russian sextants are clones of German Equipement.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 Rissian sextant should be the same.I would be more concerned about Collumation 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 collumated there are many places that will do that service for you. The Clausen Inst. Co. is the importer for Freiberger sextants in the U.S. and I am sure they have a website.If you need an owners manual maybe they can help. Hope this helps you out and good luck.
