Orion 9966 manual

IN 256 Rev . A 08/05 Providi ng Excep tional Consumer Optica l Produc ts Since 1975 Customer Support (800) 676-1343 E-mail: support@telescope.com Corporate Offices (831) 763-7000 P .O. Box 1815, Santa Cruz, CA 95061 INSTRUCTION MANUAL Orion ® SkyQuest ™ XT12 Classic #9966 Dobsonian Reflecting T elescope[...]

2 Figure 1. The SkyQuest XT12 Classic Dobsonian. Right side panel Secondary mirror holder with 4-vane spider (not visible) Navigation knob Front brace Handle T op baseplate Ground baseplate Finder scope Finder scope bracket Eyepiece Focuser Optical T ube Altitude side bearing CorrecT ension (XT) Friction Optimization System Eyepiece rack Primary mi[...]

3 T able of Contents 1. Unpacking ............................................... 3 2. Assembly ................................................. 4 3. Using Y our T elescope .............................. 8 4. Collimation (Aligning the Mirrors) .......... 1 1 5. Astronomical Observing ........................ 13 6. Care and maintenance ............[...]

4 Box #3: Primary Mirror and Cell Qty . Description 1 Primary mirror 1 Mirror cell 3 Collimation knobs 3 Nylon washers 3 Springs 2. Assembly Now that you have unpacked the boxes and familiarized yourself with all the parts in front of you, it’s time to begin assembly . Assembly of the Optical T ube In order to prevent damage to the primary mirror[...]

5 of engagement on the shafts . The mirror cell is now ready to be installed into the tube. Assembling the SkyQuest XT12 mirror cell to the tube can be a bit tricky . This is because the large diameter and thin steel of the tube will cause the tube to become somewhat out of round once the rear end ring is removed. T o assemble the mirror cell to th[...]

6 tighten them until firm, but be careful not to strip the holes by over-tightening. If you use an electric screwdriver , do final tightening with a standard screwdriver to avoid stripping. 1. Screw the plastic feet into the underside of the ground baseplate (A) using the se lf-tapping wood s crews pr ovid- ed, with a Phillips screwdriver . Insert [...]

7 panel of the base you will notice two predrilled starter holes, about 6" apart. T ake the black wood screws and thread them into the starter holes with a Phillips screwdriver . Then you can “keyhole” the eyepiece rack onto the wood screws and con- tinue tightening the screws (Figure 1 1). If you want to be able to remove the rack, do not[...]

8 should seat onto the narrow end of the spacer . Repeat this procedure for the other altitude side bearing. 3. Attach a pull loop to the free end of each spring. Slide the loop through the opening in the ring on the end of the spring. 4. Now , pull each spring down using the pull loop, and posi- tion the spring’ s end ring over the head of the P[...]

9 lev el, b ut it should be place d on som ewh at flat groun d or pav e- men t t o en sur e s moo th move men t o f t he tele sco pe. Remember , never point the telescope at or near the Sun with- out using a proper solar filter over the front aperture! Altitude and Azimuth The Dobsonian base of the SkyQuest XT12 permits motion of the telescope alon[...]

10 screws will be needed until the object comes into the finder scope’s field of view . The SkyQuest XT12’s finder scope uses a spring-loaded bracket that makes alignment of the finderscope very easy . As you turn either of the thumbscrews, the spring in the bracket’s tensioner moves in and out to keep the finder scope secure in the bracket. [...]

11 expect the user to compensate for heavier accessories by adding weight to the opposite end of the telescope tube. Such counterweighting systems can be expensive and unwieldy . The CorrecT ension Friction Optimization system of the SkyQuest XT12 Dobsonian, however , solves the finicky bal- ance problem. The spring coils pull the tube down onto th[...]

12 has a hole in the cente r and a silv er bot tom. This helps cente r your eye so that collimation is easy to perform. Figures 19b throug h 19e assume you ha ve the collim ation cap in place. In addition to the collimation cap, the primary mirror is marked with a circle at its exact center . This “center mark” allows you to a chi eve a pre cis[...]

13 Now , try tightening or loosening one of the larger collima- tion thumbscrews with your fingers (Figure 23). Look into the focuser and see if the secondary mirror reflection has moved closer to the center of the primary . Y ou can tell this easily with the collimation cap and mirror center mark by simply watch- ing to see if the “dot” of the[...]

14 3000 feet. Alti tude helps because it decreases the amount of distor tion c ausing atmosp here yo u are lookin g throu gh. A good way to judge if the seeing is good or not is to look at bright stars about 40° above the horizon. If the stars appear to “twinkle”, the atmosphere is significantly distorting the incom- ing light, and views at hi[...]

15 bright objects, like planets and double stars. The Moon also takes higher magnifications well. Deep-sky objects, however , typically look better at medium or low magnifications. This is because many of them are quite faint, yet have some extent (apparent width). Deep-sky objects will often disappear at higher magnifications, since greater magnif[...]

16 of the stars and locate many pretty double and multiple stars. The famous “Double-Double” in the constellation L yra and the gorgeous two-color double star Albireo in Cygnus are favor- ites. Defocusing a star slightly can help bring out its color . E. Deep-Sky Objects Under dark skies, you can observe a wealth of fascinating deep-sky objects[...]

17 possible to take pictures of bright objects. Certain photo- graphic aids, such as the Orion SteadyPix, can help in taking photos by the afocal method. 6. Car e and Maintenance If you give your telescope reasonable care, it will last a life- time. Store it in a clean, dry , dust-free place, safe from rapid changes in temperature and humidity . Do[...]

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20 One-Y ear Limited W arranty This Or ion Sky Quest X T12 Cla ssic Do bsonian Reflec ting T elesc ope is warrant ed agai nst def ects in materi als or workman - ship for a perio d of one y ear from the date of purch ase. This wa rranty i s for the benefit of the or iginal r etail pu rchaser only . During this warran ty period Orion T eles copes &a[...]