User manual MEADE MA 12MM

[. . . ] Astrometric Reticle Scales: There are 4 reticle scales etched into the glass reticle (Fig. 2) of the eyepiece that correspond to the table below: Scale 1 Type Linear Diameter Scale Semicircular Position Angle Scale Description 0 to 50 Units; Segmented in Single Units with Circular Center Position 0 to 90 Degrees with Circular Center Position ® 3 1 MEADE MA ASTROMET ILLUMINATED 2 Fig. (1) Eyelens Focuser; (2) Red LED Illuminator with Continuously Variable Brightness Control; (3) Brightness Control Knob. [. . . ] Aim the telescope at or very near (within +/- 5°) the zenith (perpendicular to the ground). Release the set-screw of the eyepiece holder and rotate the Astrometric Eyepiece within the eyepiece holder so that a star drifts across the 90° mark of the Position Angle Scale and then exits across the 270° mark. Find the object that the position angle is measured for (e. g. , discernable edge or center line of a comet's jet or tail that extends across the eyepiece field of view). Read the position angle. 3. For example, if the nucleus of a comet is placed in the center of the Linear Diameter Scale, and the center of the tail (the object the PA measures for) is in-line with the first segment after 300 on the Position Angle Scale, then the PA of the center of the comet's tail is 305°. 3. 6. Important Note: The Position Angle Scale reads clockwise from 0° to 360° as used through mirror-lens Cassegrain telescopes (e. g. , Schmidt-Cassegrain, Maksutov-Cassegrain), or refractors where a diagonal mirror/prism is being used. If the Astrometric Eyepiece is being used without a diagonal prism or through a Newtonian reflecting telescope, the position angle reading should be reversed (e. g. , 90° translates to 270°). If the PA of a double-star, or other closely spaced objects is to be measured, use the Semicircular Position Angle Scale (2, Fig. To make a measurement on this scale follow the same steps outlined above, but with these important differences: · The Semicircular Position Angle Scale reads from 0° to 90° clockwise and counterclockwise. The clockwise direction is for measurements being made through mirrorlens Cassegrain telescopes (e. g. , Schmidt-Cassegrain, Maksutov-Cassegrain), or refractors where a diagonal mirror/prism is being used. Translate the 90° mark on the opposite side of the scale as 270°. The counterclockwise direction is for a Newtonian reflecting telescope or a telescope without a diagonal mirror/prism. In this case the 90° mark should be on the "left" side of the scale. Translate the 90° mark on the opposite side of the scale to 270°. 7. Once the scale is successfully calibrated along the east-west line of the sky, follow these steps to measure the position angle of a celestial object: 1. Place the reference object (e. g. , primary component of a comet nucleus) in the circular mark at the center of the Linear Diameter Scale (1, Fig 2. ). · 0 2 33 0 30 0 30 30 3 0 60 60 60 30 90 90 270 90 4 0 10 20 30 40 50 0 12 24 0 Fig. (1) Linear Diameter Scale, (2) Semicircular Position Angle Scale; (3) 360° Position Angle Scale; (4) Double Crossline/Concentric Circle Guiding Scale. 180 1 15 0 21 0 -3If the object to be measured is "below" the east-west line, then the entire reticle must be rotated 180° to position the object within the Semicircular Position Angle Scale. Place a star on the 90° mark on the Position Angle Scale Release the thumbscrew of the eyepiece holder and rotate the eyepiece until the same star is lined up on the 270° mark. Tighten the thumbscrew to lock the eyepiece in position. zWith the Semicircular Position Angle Scale turned "upside-down" the scale markings should be translated as shown: The Semicircular Position Angle Scale reads from 0° to 90° clockwise and counterclockwise. [. . . ] RGA Number Required: Prior to the return of any product or part, a Return Goods Authorization (RGA) number must be obtained by writing to Meade's Customer Service Department or by calling 800-626-3233. Each returned part or product must include a written statement detailing the nature of the claimed defect, as well as the owner's name, address, phone number, and a copy of the original sales invoice. This warranty is not valid in cases where the product has been abused or mishandled, where unauthorized repairs have been attempted or performed, or where depreciation of the product is due to normal wear-and-tear. [. . . ]