ASTRA IIIB MANUAL PDF

The Astra IIIB is an all-aluminium sextant, and when introduced quickly became popular wooden box, with an adjustment key, test certificate, and user manual. Download Astra iiib sextant manual: ?file=astra+ iiib+sextant+manual Astra III Professional Sextant. This sextant. The Astra IIIB is made by the Changzhou Celestaire Instrument Co. in China, with whom and has instructions for easy installation. We are impressed with the.

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WinAstro Astro navigation on your PC. Its low price, excellent optics, and choice of horizon mirrors and other accessories makes it the perfect selection for beginners.

Also, and probably more importantly, many people find that the extra weight makes the sextant steadier when taking a sight. The sextant is electrically lighted by an LED on the arc and drum. Note that aluminum alloy sextants are not unique to this Chinese manufacturer, even the makers of the expensive brass versions offer aluminum alloy models, sometimes even more expensive than their brass models. The sight scope is 3.

The ebook must be read from a Windows PC. Since then its specification has steadily been improved, and it continues to offer good value for money.

The Astra optics are excellent and the instrument has a good feel to it. It is also been reviewed as the best source available for how to use metal sextants. Practice Artificial Horizon This bubble horizon replaces the normal scope on the sextant, and allows you to take a sight without being able to view the horizon.

Instruction manual for Astra III-B Marine – Search Yale Digital Content

Other differences are that it has an improved handle design, and the light can be dimmed for when viewing faint stars. It has long been used by many manufacturers for lightweight versions of their heavier brass or bronze sextants in order to reduce arm fatigue and unsteadiness among infrequent users.

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We are impressed with the ioib to which each component of the sextant is tested.

It is made of blackplastic, and has a matt black interior to astrra refletions. The index mirror is rectangular in shape and is the same size as used more expensive sextants. You then change the sextant angle to bring the body down astrq the hairline. Whilst the magnification obtained through having a scope instead of a plain sight tube can make your sights more accurate, there are times when a plain sight tube is an advantage.

The sextant comes in a varnished wooden box, with an adjustment key, test certificate, and user manual. Aluminum alloy is not new to sextant construction.

Sextant Astra IIIB

Yet, we know several asrra navigators who prefer the ASTRA IIIB merely because they can leave their expensive models at home without sacrificing noticeable accuracy. It comes mounted in a rectangular frame and has instructions for easy installation. They offer good value for money metal sextants – not as good as Freiberger and other high end sextants, but considerably more accurate than plastic ones.

We also carry a full line astr Davis plastic sextants.

This means the sextant does not have to be held as steady for them. Random units have been tested by us and several professional navigators, with results that rival the most expensive German and Japanese models. Slip-on Rubber Eyecup for Scope. For example, each mirror and shade glass is tested for perfect flatness astrx the Fresnel diffraction pattern method.

Beschrijving Metalen halfzicht Sextant in traditionele houten kist.

Astra IIIB Sextant

One can always use the price of this new one as a reference for evaluating the price of such an opportunity. It can take the optional rubber eye cap. The sextant comes with the traditional, manyal “4×40” telescope. An index mirror upgrade kit is available for older astrw having smaller, round, index mirrors. If you are a beginner, the much larger field of view makes it easier to identify the stars through the sextant; and if the boat is moving a lot a sight tube makes it easier to keep the body in view.

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Construction Details The frame is made from lightweight aluminum alloy which resists corrosion.

Astra IIIB sextant

Bargains on used instruments still exist. The Astra IIIB is an all-aluminium sextant, and when introduced quickly became popular due to its low price compared to other models then on the market. This bubble horizon replaces the normal scope asta the sextant, and allows you to take a sight without being able to view the horizon.

Its popularity has spread throughout the rest of the world as well, making it the the most recognized and supported sextant worldwide. Sight Tube Whilst the magnification obtained through having a scope instead of a plain sight tube can make your sights xstra accurate, there are times when a plain sight tube is astar advantage. Astra sextants are manufactured in China as a brand name for Celestaire. The Astra is dependable and more than accurate enough for the job.

We recommend the traditional mirror as opposed to so-called “full view” models, and the deluxe version, which has the larger mirrors. A serial number is provided at the time of sextant purchase.