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Re: Sextant Comparisons -> to Joel Jacobs...
From: Courtney Thomas
Date: 2004 Mar 20, 20:16 -0500
From: Courtney Thomas
Date: 2004 Mar 20, 20:16 -0500
Thank you Joel. Are the T and M sextants equivalent in quality ? Courtney Joel Jacobs wrote: > Hi Courtney, > > I think it has been explained here before that under the Cyrillic alphabet, > the English C is the same as the Russian S so that SNO-T and SNO-T are the > same sextant. Your SNO-T sextant has many similarities to the German > Freiberger, including its paint, but is appreciably smaller in size. It is a > more expensive sextant than the SNO-M. I have seen the SNO-M in both black, > and military green. > > Joel > > > ----- Original Message ----- > From: "Courtney Thomas"> To: > Sent: Saturday, March 20, 2004 5:39 PM > Subject: Re: Sextant Comparisons -> to Joel Jacobs... > > > >>Joel, >> >>I should have said...I have a SNO-M, not T. Anyway, the awful olive >>color and the one scope. I got it real cheap and want to bring it up to >>snuff. >> >>I also have a more recent SNO-T which has an agreable silver color and 2 >>scopes. >> >>But I obviously agree that the Russian sextants are good and a great buy. >> >>Appreciatively, >>Courtney >> >> >> >>Courtney Thomas wrote: >> >> >>>Joel, >>> >>>I have one and hate the color, but am otherwise satisfied. >>> >>>What is "black wrinkle paint" ? Where do I get it and how is it applied >>>for optimal esthetics ? >>> >>>Where can I get a proper scope for CELNAV ? How much ? >>> >>>Appreciatively, >>> >>>Courtney >>> >>> >>> >>>Joel Jacobs wrote: >>> >>> >>>>Fred, >>>> >>>>Your best bet is a Russian SNO-T sextant. They are very underrated, >>>>and have >>>>most all the features of the preferred brands, and even come in a >>>> > smaller > >>>>size for convenience. However, most of them are sold with only an >>>>astronomical scope which presents the image inverted, and IMO are >>>> > useless > >>>>for CELNAV. Configured with the 7 x scope, you should be able to buy >>>>one for >>>>$250.00 because they are a drudge on the market with out an erect >>>> > imaging > >>>>scope. You can read about them in detail at: >>>> >>>> >>>> > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3712084763&category=37971 > >>>>&sspagename=STRK%3AMESSE%3AIT&rd=1 >>>> >>>>They wont meet your standards for good looks, but you can get some >>>> > black > >>>>wrinkle paint, and make them look as pretty as you like. They are a >>>> > great > >>>>buy. >>>> >>>>Joel Jacobs >>>> >>>> >>>> >>>>----- Original Message ----- >>>>From: "Fred Hebard" >>>>To: >>>>Sent: Saturday, March 20, 2004 12:15 PM >>>>Subject: Re: Sextant Comparisons >>>> >>>> >>>> >>>> >>>>>Doug, >>>>> >>>>>No, I don't collect older equipment. I have been trying to acquire a >>>>>sextant suitable for lunar observations, so I look for sextants with >>>>>defects on Ebay that might still be serviceable. >>>>> >>>>>I have one British Husun that only has the "star scope." It's a 2.5x >>>>>power scope. It's my understanding that a more powerful one would >>>>> > give > >>>>>more precise readings. I checked this by buying an old Simex-type >>>>>sextant, which subsequently was sold. I have been looking for another >>>>>Husun with the inverting telescope or another instrument. The Cassens >>>>>& Plath was the first that came up which was suitable. >>>>> >>>>>In comparing the Cassens and Plath to the Husun, I would say, overall, >>>>>that I prefer the Husun at this time. It's prettier, with the >>>>>silver-inlayed arc; this increases my fondness for the instrument. >>>>> > The > >>>>>black crinkle finish is nicer than the Cassens and Plath's. All the >>>>>screws are varnished or painted brass; there's no aluminum to corrode >>>>>with steel screws or react with the brass or bronze (There's no >>>>>corrosion on my Cassens and Plath; it doesn't appear ever to have been >>>>>used for extended periods). >>>>> >>>>>The 2.5x scope on the Husun has a very wide field of view, wider than >>>>>the 4x "star scope" on the Cassens and Plath. I have seen no optical >>>>>aberrations in the Husun, while the Cassens and Plath star scope has >>>>>chromatic aberration, which rather surprised me (reddish fringe on the >>>>>bottom of the image and bluish fringe on the top). The aberration >>>>>makes it more difficult to check index error by measuring the sun's >>>>>semidiameter. >>>>> >>>>>The handle on the Husun is straight up and down. This makes some >>>>>lunars easier, whereas the tilted handle on both brands of Plaths, >>>>>while it makes looking at the horizon easier on the wrist, makes >>>>> > lunars > >>>>>more difficult. When holding the instrument between shots or while >>>>>waiting, the Husun is less fatiguing to hold >>>>> >>>>>The star scope on the Husun is in close to the horizon mirror. This >>>>>centers weight in the instrument, making it less fatiguing to hold. >>>>>Being close in to the horizon mirror, the smaller mirror does not >>>>>restrict the field of view of the instrument as much as one might >>>>>suppose. I suppose the larger mirrors would be "faster" optically, >>>>>however. >>>>> >>>>>The perceived weight of the two instruments is similar. I have not >>>>>actually weighed them. >>>>> >>>>>The lamp on the Husun can be swung around to illuminate my wrist band >>>>>when recording data. The lamp on the Cassens and Plath is guided to >>>>>illuminate the scales only, making recording data more difficult. >>>>> >>>>>The box on the Husun is significantly smaller than the box on the >>>>> > other > >>>>>instruments. >>>>> >>>>>These are my impressions after two days. >>>>> >>>>>Fred >>>>> >>>>------------------------------------------------------------------------ >>>> >>>>>Frederick V. Hebard, PhD Email: >>>>> > mailto:Fred@acf.org > >>>>>Staff Pathologist, Meadowview Research Farms Web: http://www.acf.org >>>>>American Chestnut Foundation Phone: (276) 944-4631 >>>>>14005 Glenbrook Ave. Fax: (276) 944-0934 >>>>>Meadowview, VA 24361 >>>>> >>>>>On Mar 19, 2004, at 5:44 PM, Royer, Doug wrote: >>>>> >>>>> >>>>> >>>>>>By the way,do you collect older sextants?Don't you also have some >>>>>> > older > >>>>>>British equipment you wrote about in the past?Just curious. >>>>>> >>>>>> >>> >>>-- >>>Courtney Thomas >>>s/v Mutiny >>>lying Oriental, NC >>>WDB5619 >>> >>> >> >>-- >>Courtney Thomas >>s/v Mutiny >>lying Oriental, NC >>WDB5619 >> > -- Courtney Thomas s/v Mutiny lying Oriental, NC WDB5619