Summary of Contents for ORION TELESCOPES & BINOCULARS SkyQuest XT10 9990
Page 1
INSTRUCTION MANUAL Orion ® SkyQuest XT10 ™ Dobsonian Reflector #9990 Customer Support (800) 676-1343 E-mail: support@telescope.com Corporate Offices (831) 763-7000 P.O. Box 1815, Santa Cruz, CA 95061 Providing Exceptional Consumer Optical Products Since 1975...
Page 2
Secondary mirror holder with 3-vane spider (not visible) Finder scope Finder scope bracket Eyepiece Focus knob Optical tube Altitude side bearing CorrecTension (XT) Friction Optimization system Right side panel Pull loop Front brace Eyepiece rack Handle Primary mirror cell Left side panel Top baseplate Ground baseplate Foot (3)
Table of Contents 1. Unpacking..........................3 2. Assembly ..........................4 3. Using Your Telescope ......................7 4. Collimation (Aligning the Mirrors) ..................10 5. Astronomical Observing ....................... 12 6. Care and Maintenance ......................15 7. Specifications........................16 1. Unpacking Moon filter Eyepiece rack The telescope will arrive in two boxes, one containing the Eyepiece rack mounting wood screws (length 3/4")
2. Assembly the top baseplate (D) with the remaining six base assem- bly screws in the predrilled holes. Tighten all six screws. Now that you have unpacked the boxes and familiarized your- 4. Tighten the six side screws installed earlier. self with all the parts in front of you, it’s time to begin 5.
Page 5
Installing the Eyepiece Rack The aluminum eyepiece rack is a standard accessory on SkyQuest XT10 Dobsonians. It holds four 1.25" eyepieces in a convenient place on the base, within easy reach while you’re observing. A 1.25" barlow lens also can be held in the rack. About halfway down the left side panel of the base you will notice two predrilled starter holes, about 6"...
Page 6
black 1/4" washers over the end of the screw. Now, thread screw (installed in step 1) and onto the narrow part of the the screw into the hole in the base side panel just below nylon spacer, as shown in Figure 7. You needn’t attach the cradle.
When moving the telescope, it may be convenient to grasp Focus 1.25" eyepiece adapter the front end of the telescope tube so that your fingers just lock protrude into it; this provides a convenient “handle”. thumb screw 2" eyepiece adapter Focus knob Figure 9: The large format focuser with eyepiece adapters...
Page 8
observe with your glasses off by just refocusing the telescope point you want to look at. Then look through the telescope’s the needed amount. If you suffer from severe astigmatism, eyepiece to see if that point is centered in the field of view. If it however, you may find images noticeably sharper with your is, the job is done.
Page 9
length of the eyepiece. Therefore, by using eyepieces of dif- in an eyepiece case. You can also remove the finder scope ferent focal lengths, the resultant magnification can be varied. and finder scope bracket, if you wish. Disengage the CorrecTension springs by unhooking them from the posts on Magnification is calculated as follows: the base, using the pull loops.
Figure 14. Collimating the optics. (a) When the mirrors are properly aligned, the view down the focuser drawtube should look like this. (b) If the optics are out of alignment, the view might look something like this. (c) Here, the secondary mirror is centered under the focuser, but it needs to be adjusted (tilted) so that the entire primary mirror is visible.
Page 11
reflections for the time being. The secondary mirror itself mary mirror reflection in the secondary mirror, as in Figure should be centered in the focuser drawtube, in the direction 14d. Don’t worry that the reflection of the secondary mirror parallel to the length of the telescope. If it isn’t, as in Figure (the smallest circle, with your eye reflected in it) is off-center, 14b, it must be adjusted.
necessary. It will take a little trial and error to get a feel for how is intended to get you ready for your voyages through the to tilt the mirror in this way to center the reflection. (It helps to night sky.
Page 13
D. Let Your Eyes Dark-Adapt eyepieces: a 25mm, which gives a magnification of 50x, and a 9mm, which gives a magnification of 139x. Other eyepieces Do not expect to go from a lighted house into the darkness of can be used to achieve higher or lower powers. It is quite the outdoors at night and immediately see faint nebulas, common for an observer to own five or more eyepieces to galaxies, and star clusters- or even very many stars, for that...
Page 14
A. The Moon ing) is necessary for a good view. You will probably see a bright “star” close by, which is Saturn’s brightest moon, Titan. With its rocky surface, the Moon is one of the easiest and most interesting targets to view with your telescope. Lunar VENUS At its brightest, Venus is the most luminous object in craters, marias, and even mountain ranges can all be clear- the sky, excluding the Sun and the Moon.
lations in the night sky, you will need to get a planisphere to If you have trouble finding the object, start the starhop again identify them. from the brightest star near the object you wish to view. This time, be sure the stars indicated on the star chart are in fact Start by choosing bright objects to view.
The large primary mirror and the elliptical secondary mirror dirty mirror). Wipe the mirror under water with clean cotton balls, of your telescope are front-surface aluminized and over- using extremely light pressure and stroking in straight lines coated with hard silicon monoxide, which prevents the across the surface.
Need help?
Do you have a question about the SkyQuest XT10 9990 and is the answer not in the manual?
Questions and answers